Stanford Research Systems SR510 User Manual

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MODEL SR510

LOCK-IN AMPLIFIER

1290- D Reamwood Av enue

Sunnyvale, CA 940 89 U.S.A. Phone: ( 408) 744- 9040 • Fax: (408) 744-9049 Email: info@thinkSRS.com • www.thinkSRS.com

Stanford Resear c h S y s tems, I nc .

Revision: 3.3 (11/2003)

TABLE OF CONTENTS

Condensed Information

SAFETY and Preparation for use 1 Symbols 2 Specifications 3 Front Panel Summary 5 Abridged Command List 6 Status Byte Definition 7 Configuration Switches 7

Guide to Operation

Front Panel 8 Signal Inputs 8 Signal Filters 8 Sensitivity 8 Dynamic Reserve 9 Status Indicators 9 Display Select 9 Output 9 Expand Function 9 Rel Function 9 Offset 10 Time Constants 10 Noise Measurements 10 Reference Input and Trigger Levels 11 Phase Controls 11 Power Switch 12 Local/Remote Operation 12 Default Settings 12

Rear Panel 13 AC Power 13 GPIB (IEEE-488) Connector 13 RS232 Interface 13 Signal Monitor Output 13 Pre-Amp Connector 13 A/D Inputs and D/A Outputs 13 Ratio Feature 13 Internal Oscillator 13

Guide to Programming

Communications 15 Command Syntax 15 Status LED's 15 RS232 Echo Feature 16 Try-out with an ASCII Terminal 16

Command List 17 Status Byte 20 Errors 20 Reset Command 20 Trouble-Shooting Interface Problems 21 Common Hardware Problems 21 Common Software Problems 21

RS232 Interface

Introduction to the RS232 21 Data Communications Equipment 22 Wait Command 22 Termination Sequence 22

GPIB (IEEE-488) Interface

Introduction to the GPIB 22 GPIB Capabilities 22 Response to Special GPIB commands 22 Serial Polls and SRQ's 23 Echo Mode using the RS232 23 Using Both the RS232 & GPIB 23

Lock-in Technique

Introduction to Lock-in Amplifiers 24 Measurement Example 24 Understanding the Specifications 25 Shielding and Ground Loops 25 Dynamic Reserve 26 Current Input 26 Auto-Tracking Bandpass Filter 26 Notch Filters 27 Frequency Range 27 Noise Measurements 27 Output Filters 27 Ratio Capability 27 Computer Interface 27 Internal Oscillator 27

SR510 Block Diagram

Block Diagram 28 Signal Channel 29 Reference Channel 29 Phase-Sensitive Detector 29 DC Amplifier and System Gain 29 Microprocessor System 29

Circuit Description

Introduction 30 Signal Amplifier 30 Current Amplifier 30 Notch Filters 30 Bandpass Filter 30 Reference Oscillator 31 PSD, LP Filters and DC Amplifier 31 Analog Output 31 A/D's 31 D/A's 32 Expand 32 Front Panel 32 Microprocessor Control 32

RS232 Interface 32 GPIB Interface 32 Power Supplies 33 Internal Oscillator 33

Calibration and Repair

Introduction 34 Multiplier Adjustments 34 Amplifier and Filter Adjustments 34 CMRR Adjustment 34 Line Notch Filter Adjustment 35 2xLine Notch Filter Adjustment 35 Repairing Damaged Front-End 35

Appendix A: Noise Sources and Cures

Johnson Noise 36 '1/f' Noise 36 Noise Spectrum 36 Capacitive Coupling 37 Inductive Coupling 37 Ground Loops 38 Microphonics 38 Thermocouple Effect 38

Appendix B: RS232

Simplest Case Using the RS232 39 Using Control Lines 39 Baud Rates 39 Stop Bits 40 Parity 40 Voltage Levels 40 'Eavesdropping' 40

Appendix C: GPIB

Introduction to the GPIB 41 Bus Description 41

Appendix D: Program Examples

IBM PC, Microsoft Basic, via RS232 42 IBM PC, Microsoft Fortran, via RS232 43 IBM PC, Microsoft C, via RS232 45 IBM PC, Microsoft Basic, via GPIB 47 HP-85, HP Basic, via HPIB 49

Documentation

Part Numbering and Locations 50 Parts List, Main Assembly 51 Parts List, Internal Oscillator 65 Parts List, Miscellaneous 66 Parts List, Front Panel 67 Schematic Diagrams 71

Safety and Preparation for Use

***CAUTION***: This instr um ent m ay be damaged if oper at ed with the LINE VOLTAG E SELECTOR set f or the wrong applied ac input-sour ce volt age or if the wrong f use is installed.

LINE VOLTAGE SELECTION

The SR510 operates fr om a 100V, 120V, 220V, or 240V nominal ac power source having a line frequency of 50 or 60 Hz. Before connecting the power cord to a power source, v erify that the LINE VOLTAGE SELECTOR car d, located in the rear panel fuse holder, is set so that the correct ac input voltage value is visible.

Conversion to other ac input volt ages requires a change in the fuse holder volt age car d pos ition and fuse value. Disconnect the power cord, open the fuse holder cover door and rotat e the fuse-pull lever to rem ove the fuse. Remove the small printed circuit board and select t he oper at ing voltage by orienting the printed c ircuit boar d to position the desir ed voltage to be visible when pushed firmly into it s slot . Rotate the fuse-pull lever back into its normal position and insert t he cor r ect fuse into the fuse holder.

LINE FUS E

Verify that the correct line fuse is installed befor e connecting the line cord. For 100V and 120V, use a ½ Amp fuse and for 220V and 240V, use a 1/4 Amp fuse.

OPERATE WITH COVERS IN

PLACE

To avoid personal injury, do not remov e the product cov er s or panels. Do not operate the product without all covers and panels in place.

WARNING REGARDING USE

WITH PH OTOMULTIPLIERS

It is relatively easy to dam age t he signal inputs if a photomultiplier is used improper ly with t he lock-in amplifier. W hen left c ompletely unt erminated, a PMT will charge a c ab le t o a few hundred volts in a ver y short time. If this cable is connected to t he lockin, the stored charge may dam age the front-end transist or s. To avoid this problem, pr ovide a leakage path of about 100 KΩ to ground inside the base of the PMT to prev ent charge acc um ulation.

LINE CORD

This instrument has a det achable, three- wire power cord with a thr ee- contact plug for connect ion to both the power sourc e and pr otective gr ound. The protect ive gr ound cont ac t connect s to the accessible metal part s of the instr um ent. To prevent electrical shock, always use a power sour ce out let that has a properly grounded pr ot ec t ive- gr ound cont act.

SR510 Specification Summary

General

Power 100, 120, 220, 240 VAC (50/60 Hz); 35 Watts Max Mechanical 17" x 17" x 3.5" (Rack Mount Included) 12 lbs. Warranty Two years parts and labor.

Signal Channel

Inputs Voltage: Single-ended or True Differential Current: 10 Impedance Voltage: 100 MΩ + 25 pF, ac coupled Current: 1 kΩ to virtual ground Full Scale Voltage: 100 nV (10 nV on expand) to 500 mV Sensitivity Current: 100 fA to 0.5 µA Maximum Voltage: 100 VDC, 10 VAC damage threshold Inputs 2 VAC peak-to-peak saturation Current: 10 µA damage threshold 1 µA ac peak-to-peak saturation Noise Voltage: 7 nV/√Hz at 1 kHz Current: 0.13 pA/√Hz at 1 kHz Common Mode Range: 1 Volt peak; Rejection: 100 dB dc to 1KHz Above 1KHz the CMRR degrades by 6 dB/Octave Gain Accuracy 1% (2 Hz to 100KHz) Gain Stability 200 ppm/°C Signal Filters 60 Hz notch, -50 dB (Q=10, adjustable from 45 to 65 Hz) 120 Hz notch, -50 dB (Q=10, adjustable from 100 to 130 Hz)) Tracking bandpass set to within 1% of ref freq (Q=5) Dynamic Reserve 20 dB LOW (1 µV to 500 mV sensitivity) 40 dB NORM (100 nV to 50 mV sensitivity) 60 dB HIGH (100 nV to 5 mV sensitivity) Bandpass filter adds 20 dB to dynamic reserve Line Notch filters increase dynamic reserve to 100 dB

Volts/Amp

Reference Channel

Frequency 0.5 Hz to 100 kHz Input Impedance 1 MΩ, ac coupled Trigger SINE: 100 mV minimum, 1Vrms nominal PULSE: ±1 Volt, 1 µsec minimum width Mode Fundamental (f) or 2nd Harmonic (2f)

Acquisition Time 25 Sec at 1 Hz

6 Sec at 10 Hz

2 Sec at 10 kHz Slew Rate 1 decade per 10 S at 1 kHz Phase Control 90° shifts

Fine shifts in 0.025° s t eps Phase Noise 0.01° r m s at 1 kHz, 100 msec, 12 dB TC Phase Drift 0.1°/°C Phase Error Less than 1° above 10Hz

Demodulator

Stab ility 5 ppm /°C on LOW dynamic reserv e

50 ppm/°C on NORM dynamic reserve

500 ppm/°C on HIG H dynam ic reserve Time Constants Pre: 1msec to 100 s ec (6 dB/Octav e)

Post: 1sec, 0. 1 sec, none (6 dB/Octave) or none Offset Up to 1X full scale (10X on expand) Harmonic Rej -55 dB (bandpass f ilter in)

Outputs & Interfaces

Outputs X (RcosØ), X Offset, Noise Output Meter 2% Precision mirror ed analog m et er Output LCD Four digit aut o- r anging LCD display shows same values as t he analog m et er s Output BNC ±10 V output corresponds to full scale input

<1Ω output impedance Reference LCD Four digit LCD display for r eference phase shift or frequency RS232 Int er f ace contr ols all funct ions. Baud rates from 300 to 19.2 K GPI B Inter face cont r o ls a ll f u n c tions. (I EEE-488 Std) A/D 4 BNC inputs with 13 bit resolution ( ± 10. 24 V) D/A 2 BNC outputs with 13 bit r esolution ( ± 10. 24 V) Ratio Ratio output equals 10X output divided by the Denom inator input . Interna l Oscillat o r Range: 1 Hz to 100 kHz, 1% accuracy

Stability: 150 ppm/°C

Distortion: 2% THD

Amplitude: 1% accurac y, 500 ppm/°C st ability

Front Panel Summary

Signal Inputs Single Ended (A), Tr ue Diff erential (A-B), or Current (I) Signal Filters Bandpass: Q-of- 5 Auto-tracking f ilter (In or Out)

Line Notch: Q- of - 10 Notch Filter at line frequency ( I n or Out) 2XLine Notch: Q-of - 10 Notch Filter at twice line frequency ( I n or Out)

Sensitivity Full scale sensitivity f r om 100 nV to 500 mV RMS for voltage inputs

or fr om 100 fA to 500 nA RMS for current inputs.

Dynamic Reserve Select Dynam ic Reserve Stability Sensitivity Rang es

LOW 20 dB 5 ppm 1 µV to 500 mV NORM 40 dB 50 ppm 100 nV to 50 mV HIGH 60 dB 500 ppm 100 nV t o 5 mV

Status I ndicat or s OVLD Signal O ver load

UNLK PLL is not locked to the referenc e input ERR I llegal or Unrecognized command ACT RS232 or GPIB interface Activity REM Remot e m ode: front panel has been locked-out

Display Select X Signal Amplitude at t he select ed phase ( AcosØ )

OFST Display the off set which is being added to the signal output

NOISE Compute and display t he noise on t he signal Analog Meters Displays Signal, Offset, or Noise as a fraction of full scale Output LCD's Displays Signal, Offset, or Noise in absolute units Output BNC's Output follows Analog Meter, ± 10 V for ± full scale Expand Multiplies the Analog Met er and Out put voltage by a factor X1 or X10. REL Set the Offset to null the output: subsequent readings are relat ive readings. Offset Enables or Disables Offset, and allows any offset (up to full scale) to be enter ed. Time Constants Pre-filter has time const ant s from 1 mS to 100 S (6 dB/Octave)

Post-f ilter has time const ant s of 0, 0.1 or 1.0 S (6 dB/Octave) ENBW Equivalent Noise Bandwidth. Specifies t he bandwidth when making Noise

measurem ent s. (1Hz or 10 Hz ENBW) Reference I nput 1 MΩ Input, 0. 5 Hz to 100 KHz, 100 mV minimum Reference Tr igger Trigger on r ising edge, z er o cr os sing, or f alling edge f/2f Mode PLL can lock t o eit her X1 or X2 of the reference input frequency Phase Controls Adjust phase in smoothly accelerating 0.025° steps , or by

90° steps. Pres s both 90° buttons to zero the phase. Reference LCD Display refer enc e phase sett ing or r eference frequenc y Power Switch Instr um ent settings f r om the last use are recalled on power-up

Abridged Command List

A Return t he ‘REL’ Status A0 Turn t he ‘REL’ off A1 Turn t he ‘REL’ on

B Return Bandpass Filter St at us B0 Take out t he Bandpass Filter B1 Put in the Bandpass Filter

C Retur n the Reference LCD Status C0 Display the Reference Fr equency C1 Display t he Ref er ence Phase Shift

N Retur n the ENBW sett ing N0 Select 1 Hz ENBW N1 Select 1 0 Hz ENBW

O Ret ur n O ffs et Stat us O0 Turn off Offset O1,v Turn on Offset, v = offset

P Return t he Phase Set t ing Pv Set the Phase to v. Abs(v) < 999 deg

D Retur n Dynam ic Reserve Set t ing D0 Set DR to LOW range D1 Set DR to NORM range D2 Set DR to HIGH range

En Return Expand St at us En,0 Turn Expand off En,1 Turn Expand on

F Return the Ref er ence Fr equenc y G Ret ur n t he Sensit ivity Set t ing

G1 Select 10 nV Full-Scale ... (G 1- G3 with SRS preamp only) G24 Select 500 mV Full-Scale

H Retur n Pr eam p St at us (1=inst alled) I Ret ur n t he Rem ot e/ Local Status

I0 Select Local: Fr ont panel act ive I1 Select Remote: Front panel inactive I2 Sele c t Remote with f u ll lo c k -out

J Set RS232 End-of-Record to <cr> Jn,m,o,p Set End-of-record to n,m,o,p

K1 Simulates Key-pr ess of button #1 ... (see un- abr idged comm and list) K32 Simulates Key- pr ess of but t on #32

Q Ret ur n t he value shown on t he Output

LCD

R Retur n the trigger mode R0 Set the trigger for rising edge R1 Set the trigger for + zero crossing R2 Set the trigger for falling edge

S Return t he display st at us S0 Disp lay X = Aco s Ø S1 Display Offset setting S2 Dis play Noise

T1 Return pre-filter setting T1,1 Set the pre-filter TC to 1 mS ... T1,11 Set the pre-filter TC to 100 S

T2 Return the post-filter sett ing T2,0 Remove post filter T2,1 Set the post filter TC to 0.1 S T2,2 Set the post filter TC to 1.0 S

V Return t he value of the SRQ mask Vn Set the SRQ Mask to the value n

(See the Stat us Byte def inition)

W Return the RS232 wait inter val Wn Set RS232 wait interval to nX4mS

L1 Return Stat us of Line Notch Filter L1,0 Remove Line Notch Filter L1,1 Insert Line Notc h Filter

L2 Return Stat us of 2XLine Filter L2,0 Remove 2XLine Notch Filter L2,1 Insert 2XLine Notch Filter

M Return t he f/2f Stat us M0 Set refer enc e mode to f M1 Set refer enc e mode to 2f

Xn Return t he v oltage at the rear panel

analog port n. ( n from 1 to 6)

X5,v Set analog port 5 to voltage v X6,v Set analog port 6 to voltage v

Y Return t he St at us Byte value Yn Test bit n of the Status Byte

Z Reset to def ault s ettings and cancel

all pending command

Status Byte Definition

Bit Meaning 0 Magnitude too small to calculat e

phase 1 Command Parameter is out-of -range 2 No detectable refer ence input 3 PLL is not locked to the reference 4 Signal Overload 5 Auto-off set failed: signal too large 6 SRQ generated 7 Unrecognized or illegal command

Configuration S witches

There are t wo banks of 8 switches, SW1 and SW2, located on t he rear panel. SW1 sets the GPIB address and SW2 set s the RS232 paramet er s. The conf igurat ion switches ar e read continuously and any changes will b e e ffective immediately.

SW1:GPIB Mode Switches

Bit Example Function 1 } up GPIB Address Switches

2 } up Address 0 to 30 allowed 3 } up 'up' for bit = 1 4 } down 'down' f or bit = 0 5 } up (Most Significant Bit)

6 down 'down' t o echo on RS232

(norm ally 'up')

7 up Not Used 8 up Not Used

If the GPIB mode switches ar e set as shown in the example column above, t hen the lockin will be addressed as G PIB device #23, and all GPI B commands and dat a will b e e c hoed over t he RS232 for de-bugging purposes.

SW2:RS232 Mode Swi t ches

Bit 1 Bit 2 Bit 3 Baud Rate up up up 19200

down up up 9600 up down up 4800 down down up 2400 up up down 1200 down up down 600 up down down 300

Bit Setting Explanation 4 up Odd parity

down Even parit y

5 up No par ity

down Parit y enabled

6 up No echo ( f or comput er )

down Echo mode ( for terminal)

7 up Two st op bits

down O ne st op bit 8 unused Eight data bits ar e always sent, regar dless of the

parity set t ing. The most significant bit is always zero.

Example: Bit 1 'down' and all others 'up' for RS232 communication at 9600 baud, no par it y, two stop bits, and no echo or prom pt s by the SR510.

SR510 Guide to Operation Front Panel

The front panel has been designed to be almost self-explanator y . The effec t of each key press is usually reflected in the c hange of a near by LED indicator or by a change in t he quant it y shown on a digital display. This discussion explains each section of t he front panel, pr oceeding left to right .

Signal Inputs

There are t hr ee input connector s locat ed in the SIGNAL INPUT section of the front panel. The

rocker switch locat ed abov e t he B input selects the input mode, either single-ended, A, differential, A-B, or current , I.

The A and B inputs are voltage inputs with 100 MΩ, 25 pF input impedance. Their connector shields are isolated from t he c hassis gr ound by 10Ω. These inputs are pr otect ed to 100V dc but the ac input should never ex ceed 10V peak. The

maximum ac input bef ore overload is 1V peak. The I input is a current input with an input

impedance of 1 KΩ to a virtual ground. The largest allowable dc curr ent before overload is 1

µA. No current larger than 10 mA should ever be applied to t his input. The conver sion ratio is 10

V/A, thus , the full scale current sensit ivities r ange from 100 fA to 500 nA with a max ac input before overload of 1 µA peak. You should use short cables when using the cur r ent input.

allowable signals at t he inputs . The notch frequencies ar e set at the factory to either 50 Hz or 60 Hz. The user can adjust these frequencies. (See the Maint enance and Repair section for alignment details.) These f ilter s pr ecede the bandpass filter in t he signal amplifier.

The bandpass filter has a Q of 5 and a 6 dB roll off in either direction. Thus, the pass band (between 70% pass points) is always equal to 1/5t h of the center frequency . The center frequenc y is continually adjusted t o be equal t o t he internal demodulator f r equenc y. When the refer ence mode is f, the filter tracks the reference. When the mode is 2f, the filter frequency is t wice the refer ence input frequency. The center frequency tracks as fast as the reference oscillator c a n s lew and may be used during frequency sc ans. The bandpass filter adds up to 20 dB of dynamic reserve f or noise signals outside the pass band, and increases the har m onic r ejection by at least 13dB. (2nd harm onic attenuat ed by 13 dB, higher harmonics at t enuat ed 6dB/ octave more.) If not needed to improve the dynamic reserve or the harmonic reject ion t hen t he filter should be left

OUT.

Sensitivity

The sensitivity is displayed as a v alue (1- 500) and a scale (nV, µV, mV). When using the current

input, which has a gain of 106 V/A, these scales read fA, pA, and nA. The two keys in the SENSITIVITY section mov e t he sensit ivity up and

down. If eit he r key is held d o wn, the s en s itivity will continue to change in the des ired direc t ion four times a second.

Signal Filters

There are t hr ee user selectable signal filters available; a line frequency not ch, a 2X line frequency notch, and an auto-tracking bandpass. Each of the filters has a pair of indicator LED's and a function key locat ed in the SIG NAL FILTERS

section of t he front panel. Pres sing a key will toggle the st at us of the appropr iate filter. The status of each filter is displayed as IN, filter active, or OUT, fi l te r in a c tive .

The notch filter s have a Q of 10 and a depth of at least 50 dB. Thus, the line fr equency not c h is 6 Hz wide and the 2X line notch has a width of 12 Hz. Both of these filters can incr ease the dynamic reserve up t o 50 dB at the notch frequencies. The achievable reser ve is limited by the maximum

The full scale sensitivit y can r ange from 100 nV to 500 mV. The sensitivit y indication is not changed by the EXPAND func t ion. The EXPAND function

increases the out put s ensit ivity ( Volts out / volts in) as well as the resolution of t he digital output display.

Not all dynamic reserves ar e av ailable at all sensitivities. I f the sensitivity is changed to a setting f or which the dynamic r eser ve is not allo we d , the dy n a mic res e r v e will c hange t o the next setting which is allo we d. Sensitivity takes precedence over the dynamic reserve. The sensitivity range of eac h dynam ic res er ve is shown below.

Dynamic Reserve Sensitivity Ran ge LOW 1 µV through 500 mV

NORM 100 nV t hr ough 50 m V HIGH 100 nV thr ough 5 m V

Dynam ic Reserve

REM indicates t hat t he unit is in the remote state

and that the front panel cont r ols ar e not operative. There are t wo remote stat es. The Remot e-WithLock o ut will not a llow any inputs from the front panel. The Remote- Wit hout - Lock out comm and allows you to return the front panel to operation by pressing the DI SPL AY UP key.

The dynamic reser ve ( DR) is set using the keys in the DYNAMIC RES ERVE section. The r eser v e is

displayed by the three indicator LED's, HIGH, NORM, LOW. Only those dynamic reserve settings available for the sensitivity are allowed (see above table) . For example, when the

sensitivity is 500 mV, the DR will always b e LOW. The dynamic reser ve and out put st ability of e a c h

setting ar e shown below. Setting Dy n amic Reserve Ou tput Sta bility

(ppm/°C) LOW 20 dB 5 NORM 40 dB 50 HIGH 60 dB 500

Since a higher DR results in degraded output sta b ility, y ou s hould use t he lowest DR sett ing f or which there is no overload indication. Note t hat using the Bandpass Filter prov ides about 20dB of additional DR and so allows you to oper at e with a lower DR s etting .

Status

Dip lay Sel ect

The keys in the DISPLAY section select the paramet er to be displayed on the out put meters

and the output on the OUT PUT BNC connector. The displayed param et er is indicated by one of t he

three LED’s and can be either t he demodulator output ( X), the offset (OFST), or the rm s noise

(NOISE). When displaying NOISE, the equivalent noise bandwidth (ENBW) is se lec ted in t h e TIME

CONSTANT section.

Output

The analog output is available at t he OUTPUT BNC. The input signal equal t o t he s elected full

scale sensitivity will generate a ± 10V out put when the EXPAND function is off. With the EXPAND on,

the output is multiplied by 10, eff ectively increasing the full scale sensitivity by 10. The ouptut impedanc e is <1Ω and t he output current is limited to 20 mA.

The analog meter always displays the OUTPUT voltage. Accur acy is 2% of full scale.

There are f ive STATUS LED's. OVLD indicates a signa l over load. This condition

can occur when the signal is too large, the sensitivity is too high, the dynamic reserve is too low, the off set is on, the expand is on, the time constant is not lar ge enough, or the ENBW is too large.

UNLK in d ic ates t h at the referen c e o s c illator is n o t phase locked to the external refer enc e input. This can occur if the ref erence amplitude is t oo low, t he

frequency is out of range, or the trigger m ode is incorrect f or the refer ence s ignal waveform .

ERR flashes when an er r or occ ur s on one of the computer int erfaces, such as an incorrect

command, invalid parameter, etc. ACT indicates act ivity on t he com put er interfaces.

This LED blinks every tim e a char act er is received by the SR510 or transmit t ed by the SR510.

The OUTPUT LC D disp lay pr ovides a r ead- out of the displayed paramet er in r eal units. The scale of

the displayed quantity is indicated by t he t hr ee scale LED's to the r ight of the display. This readout auto r anges and will re flect the sens itivity added when the EXPAND f unc t ion is on.

Expand

The output EXPAND is toggled by pressing the key in the EXPAND section. The expand status is indicated by the X10, ex pand on, and the X1,

expand off, LED's.

REL Function

The relative (aut o- zer o) func t ion is toggled by the key in the REL section. Every time t he rel stat us

LED is turned ON the offset value is set to minus the value of t he X output, thus zeroing the X out p ut. This function will work e v en if X is not the

current ly displayed param et er . If the output is greater than 1.024 t im es full scale, the REL

fun c tion will not b e a ble to zer o the output and the ON LED will blink . The of fset v a lue will then be set

to its max value. If NOISE is being displayed when the REL function is turned on, the noise ouptut will

require a sew seconds to s ettle again. If the manual OFFSET in ON when the REL

function is tur ned on, t he manual OFFSET will be turned OFF before the auto zero is done.

The REL func t ion and t he m anual OFFSET are both ways to ent er the offs et value. When the REL function is tur ned off using t he REL key the offset

is turned of f but the value is not lost. If the manual OFFSET is now tur ned ON, the off s et will b e that

set by the REL funct ion.

Offset

The OFFSET section controls the manual OFFSET. The offset is turned ON and OFF using

the upper key in the OFFSET section. When the offset is ON, the lower two keys are used to set the amount of offset. A single key press will advance the of f set by 0.025% of full scale. If the key is held down, the off set advances in larger and larger increments, the largest increment being

10% of full scale. When the offs et is turned OFF the applied offset r eturns to zero but the offset

value is not lost. The next pres s of the upper offset key (ret ur ns to ON) sets the offset to the

previously entered value. If an attempt is made to advance the offset v alue

beyond full scale, the OFFSET ON LED will blin k . An offset up to 1.024 tim es the full scale sensitivity

may be enter ed. When the expand is on, this is 10X the full scale output.

If the REL function is ON when the manual

OFFSET is t ur ned ON, the REL funct ion is tur ned OFF but the off set value rem ains the same. The OFFSET key s m ay now be used t o adjust this

offset value. Note that the offsets (either manual off set or those

generated by t he REL function) represent a fract ion of the full scale reading, and so their

absolute value will change when the s ensitivity scale is changed. A signal which has been nulled by an offset will n o t be nulled when t he sens itivity scale is changed. The analog meter and the output BNC indicate the sam e value given by the equation:

= 10Ae(AvVicosØ+Vos)

out where... Ae= 1 or 10 per the Expand setting

Av= 1/Sensitivity Vi= m agnitude of the signal Ø = phase between signal & reference

Vos= of f s et (fract ion of FS < 1.024)

Time Constant

There are t wo post demodulator low pass f ilters , labeled PRE and POST. The PRE filter precedes

the POST filter in the output amplifier. Each filter provides 6 dB/oct attenuat ion.

The PRE filter t im e const ant ranges from 1 mS to

100 S and is selected by the two keys below the PRE filter indicator LED's. Holding down either

key will a d v ance the time constant twic e a s ec o n d in the desired direction.

The POST filter time constant can be set to 1 S or

0.1 S, or can be removed altogether, NONE, using the two keys below the ENBW indicators. When set to NONE, the total attenuat ion is that of the

PRE filter, or 6 dB/ oct. When the POST filter is 1 S or 0.1S, the total attenuation is 12 dB/oct for

frequency c om ponent s beyond the larger of the POST and PRE f ilter bandwidths ( r ecipr ocal tim e

constant).

Noise

When the DISPLAY is set to NOISE, none of the PRE and POST ind icat or LED's ar e on. Inst ead,

one of the two ENBW indicator s will be on, showing the Equivalent Noise Bandwidth of the

rms noise calculation. The ENBW is set using the keys below the ENBW indicator LED's (same keys as used to set the POST f ilter ). The PRE filter keys do nothing in this case. Pressing the upper

key when the bandwidth is already 1 Hz will reset the rm s noise average (out put) to zero, res t arting

the calculation. Likewise with pr ess ing the lower key when 10 Hz is already selected.

The noise is the rms dev iation of the out put within a 1 or 10 Hz equivalent noise bandwidth about the refer ence frequency . A dc output does not contribut e t o the noise, the noise is determ ined

only by the ac 'wiggles' at t he output. By measuring the noise at dif f erent frequencies, t he frequency dependenc e of t he noise densit y can be found. This usually has the form of v

The noise computat ion assum es t hat t he noise has a Gaussian distr ibution ( such as J ohnson noise). Since the com put ation takes m any time constant s (reciproc al bandwidt h) , t he noise output should be allowed to approach a st eady value before a r eading is taken. For the 1 Hz ENBW, this time is on the order of 15 to 30 seconds; for the 10 Hz ENBW , the o utp ut stabilizes much fas ter. The n ois e o u tput will var y s lig htly sinc e the re will alwa y s b e n o is e v a riation s that a r e s lo w compared t o the bandwidth. Any DC component in th e ou tput will n o t cont ribute to the noise. Howeve r , a larg e DC ou tput will c a u s e the nois e computat ion t o initially rise to a large value bef or e approaching the f inal answer. As a r esult, t he com p utatio n will take longer to settle.

To obtain a value for the noise density, t he noise reading should be divided by the squar e r oot of the ENBW. Thus, when the ENBW is 1 Hz, the noise output is the noise densit y, and when t he ENBW is 10 Hz, the noise density is the noise output divided by √10. For exam ple, if the input noise is measured to be 7 nV with the ENBW set to 1 Hz, the noise density is 7 nV/√Hz . Swit c h in g the ENBW to 10 Hz results in a faster measurem ent and a reading of 22 nV on the output. The noise density is 22 nV/√10 Hz or 7

nV/√Hz. At frequencies » 10 Hz, the noise density should be independent of t he ENBW.

noise ~

1/f.

Reference and Trigger Level

The REFERENCE I NPUT BNC is lo c a ted in t his section. The input is ac c oupled and the

impedance is 1 MΩ. The dc voltage at this input should not exceed 100 V and the largest ac signal should be less than 10 V peak. The t hree indicators above the input BNC display t he

TRIGGER MODE. The single key above the input BNC is used to select the TRIGGER MODE.

If the center TRIGGER MODE LED is on, the mode is SYMMETRIC and the reference oscillator will lock to the positive zer o cr oss ings of the ac refer ence input . The ac signal must be symmetric (e.g. sine wave, s quar e wave, etc.) and have a peak to peak amplitude gr eat er t han 100 mV. A signal with 1 Vrms am plitude is r ecommended. The phase accuracy of the reference channel is specified for a 1Vr m s sinewave in the symmetric trigger m ode.

If the upper TRIGGER MODE LED is on, the mode is POSITIVE. The trigger threshold is +1V and the ref erence oscillator will lock t o the positive going transitions of t he refer ence input . This mode tr iggers on the rising edges of a TTL type pulse train. The pulse width mus t be great er than 1 µS.

If the lo w e r TRIGGER MODE LED is on, the mode is NEGATIVE. The trigger threshold is -1V and

the referen c e o s c illa tor wil l lo c k to the negative going transitions of t he refer ence input . This mode tr iggers on a negative pulse tr ain or on the falling edges of a TTL type pulse t r ain (rem em ber ing that t he input is ac coupled). The pulse width must be greater than 1 µS. Above the TRIGGER MODE indicators are the

REFERENCE MO DE LED's. The key below the REFERENCE MO DE indicators toggles bet ween f

and 2f. When the MODE is f, the lock-in will detect s ignals at t he refer ence input fr equency. When the MODE is 2f, the lock-in det ect s signals at twice the refer ence input frequency . In either case , the referen c e os c illa tor ha s a ma x im u m frequency of 100 KHz, thus, when in the 2f mode, the ref erence input f r equency may not exceed 50 KHz.

The REFERENCE DIGITAL DISPLAY shows eith e r the ref erence o s c illa tor f r equenc y or

phaseshift. The displayed parameter toggles between the t wo whenever t he SELECT key is

pressed. The appr opr iat e sc ale indicator below the display will be on. It is useful to check the frequency display t o ver if y that the lock-in has correct ly locked t o y our ref erence. The reference frequency is m easur ed to 1 part in 256 resolution.

Phase Controls

The phase shift bet ween t he refer ence osc illator and the ref erence input is set using the f our keys in the PHASE section. The t wo keys below the FINE label increment t he phase setting in small

amounts. A single key press will change t he phase by 0.025 degrees in the desir ed direction. Holding the key down will continue to change the phase with larger and larger s t eps with t he largest step being 10 degrees. The two 90° keys are used to change t he phase by 90 degree increments . The upper key will add 90 degrees and the lower key will su btract 90 degrees. Holding both keys down at once s et s the phase

shift back to zero. The REFERENCE DIGITAL DISPLAY automatically displays t he phas e

whenever any of t he PHASE key s ar e pr essed. The phase ranges fr om -180 degr ees to +180

degrees and is the phase delay f r om the refer ence input signal.

Power

This is the instrume n t's POWER switch. When the power is turned of f, the front panel settings are

retained so t hat the inst r ument will retur n to the same settings when the power is next turned on.

When the power is tur ned on, the OUTPUT

DIGITAL DISPLAY will show the SERIAL NUMBER of the instr ument and REFERENCE DISPLAY shows the model number of the

instrument. All displays return to normal after 2 seconds.

Local and Remote

When the instr um ent is progr ammed via the computer int erface t o be in the REMOTE state

WITHO UT LO CK-OUT, the DISPLAY UP key will return the instrument to LOCAL f ront panel control. If the instr ument is in the REMOTE WITH LOCK-OUT state, no front panel key will ret u r n the status to LOCAL. In this case, a RETURN TO LOCAL c om m and m ust be s ent over the computer interfac e or the power must be turned off and back on.

Defaults

If the REL key is held down when the POWER is turned on, the instr um ent settings will be s et to the

defaults shown below instead of t he settings in effect when the power was t ur ned off.

Parameter Setting BANDPASS OUT

LINE OUT LINE X 2 OUT SENSITIVITY 500 mV DYN RES LOW DISPLAY X EXPAND OFF REL OFF OFFSET OFF (value=0) PRE TIME CONSTANT 100 mS POST TIME CONST ANT 0.1 S ENBW 1 Hz REFERENCE MO DE f TRIGGER MODE SYMMETRIC REFERENCE DISPLAY FREQUENC Y PHASE 0°

Whenever def ault values ar e used at power up, the red ERR LED will turn on f or about 3 seconds. If the ERR LED is on when the instrument is

powered on without the LOCAL key down, then the instr um ent is ignoring the ret ained settings. This can be due to a low battery.

SR510 Guide to Operation

Pin Voltage Current Available

Rear Panel

AC Power

The ac line voltage selector car d, line fuse, and line cord receptacle ar e located in t he f use holder at the left side of the rear panel. See the section, Preparati on f or Use at the front of this manual for

instruct ions on set t ing t he ac voltage selector and choosing the corr ect fuse.

GPIB Connector

The SR530 has an IEEE 488 ( G PI B) int er f ace built in. The GPIB addr ess is set using SW1 located to

the right of t he interface c onnect or s. Refer to page 7 for switch sett ing details.

RS232 Connector

The SR530 has an RS232 interf ace. The connector is conf igur ed as a DCE. The baud rate,

parity, st op bits, and echo mode are select ed using SW2 locat ed t o t he r ight of the interface

connectors . Refer to Page 7 for switch setting details.

Signal Monitor O utput

1 + 20 100 mA 2 + 5 10 m A 6 - 20 100 mA

7 Signa l gr ound 8 Digital ground

Gene ral Purpose A/D and D/A

There are f our analog input port s, labeled X1 through X4. These inputs may be digitized and read via the com put er interfaces. The range is -

10.24 V to +10.24 V and the resolution is 2.5 m V. The input impedance is 1 MΩ. A digitization can be perfor m ed in about 3 mS but the result may take longer t o transm it over the interf ac e being used.

There are t wo analog output ports, labeled X5 and X6. The voltages at t hese ports m ay be program m ed via t he computer interfaces. The range is -10.24 V to +10. 24 V and the resolution is

2.5 mV. The output impedance is <1Ω and the output cur r ent is limited to 20 mA.

Ratio

Output X5 is the ratio output when not program m ed by the computer interface or s et via

the fr ont panel. X5 becom es the ratio output whenever the unit is t ur ned on.

This BNC provides the buf f er ed output of t he signal amplifiers and f ilter s . This is the signal just before t he dem odulat or. The output impedanc e is <1Ω. When a full scale input is applied, the peakto-peak am plitude at this output is 20 mV, 200 mV or 2 V for dynamic reserve settings of high, norm, and low, respectively.

Preamp Connector

This 9 pin "D" connector provides power and control signals to ext er nal per ipherals such as pr eamplifiers. The av ailable power is descr ibed below.

The voltage at X5 is t he ratio of the det ected signal output, X, t o the analog voltage at port X1.

An output of 10 V corres ponds to a ratio of 1. The ratio is comput ed by digitizing the dem odulat or

output and t he voltage at port X1 and then taking the rat io. The resolution is 0. 0025 V. For best accuracy, t he sens itivity should be set to provide

at least a 50% full scale signal and the analog denominator ( X1) should be 5V or greater. The

ratio is updated appr oxim at ely ever y 1. 5 mS. For the Ratio feat ur e to work, the voltage at the denominator input m ust ex ceed 40 mV.

Internal Oscillator

The INTERNAL OSCILLATOR is a voltage controlled oscillat or with a sine wave output . To

use the osc illator as the ref erence s o urce, connect the REF O UTPUT on the r ear panel to the REF

INPUT on the fr ont panel. The REF OUTPUT is a 1 Vrms sine wave. The SINE OUTPUT may be used as the st imulus to the experiment . The SINE

OUTPUT can be set to three amplitudes, 1 V, 100 mV, and 10 mV (rms) using t he amplitude switch.

The output impedanc e is 600Ω. The AMP CAL screw adjusts t he am plitude.

The oscillator frequency is controlled by the VCO INPUT voltage. A voltage f r om 0V to 10V will adjust the f r equency ac cor ding t o the VCO RANGE select ed. Thr ee r anges ar e available, 1 Hz/V, 100 Hz/V, and 10 KHz/V. The input impedance is 10 kΩ. Th e FREQUENC Y CAL screw adjusts t he frequency.

There are f our ways to set the frequency:

1) Connect X5 or X6 (D/A outputs) to the VCO INPUT. The fr equency is now cont r ollable via the computer int erfaces by pr ogr amming X5 or X6.

2) If the VCO INPUT is left open, then the oscillato r will run at the top of its range (i.e. 10 Hz,

1 KHz, or 100 KHz).

3) A 10 KΩ potentiomet er may be connected from the VCO INPUT to ground. This pot will then set

the fr equency .

4) Connect t he VCO INPUT to an exter nal voltage source which can provide 0 to 10V.

In all four cases, if the REF OUTPUT is connected to the REFERENCE I NPUT on the front panel, the

frequency m ay be read on the front panel REFERENCE DIGITAL DISPLAY or via the

computer int erfaces.

SR510 Guide to Programming

An example of a multiple comm and is: G 5; T 1,4; P 45.10 <cr>

The SR510 Lock-in Amplifier is r em ot ely program m able via both RS232 and GPI B interfac es. It may be used with laboratory computer s or simply with a terminal. All front panel features ( except signal input selection and power) may be controlled and read via t he computer int erfaces. The SR510 can also read the analog output s of other laboratory instr um ents using its four gener al pur pose analog input por t s. There are also two pr ogr ammable analog output ports available to prov ide general purpos e cont r ol voltages.

Comm unicating with the SR510

Before using either the RS232 or GPIB interface, the appropr iate c onf iguration switches need t o be

set. There are two banks of 8 switches, SW1 and SW2, locat ed on t he rear panel. SW1 sets the GPIB address and SW2 sets the RS232 paramet er s. The conf igurat ion switches ar e read continuously and any changes w ill be e ffective immediately. For details on switch settings, s ee page 7 at the front of this manual.

Command Syntax

Communications with the SR510 use AS CII character s . Commands to t he SR510 may be in eith er UPPER or lower cas e .

It is not necessary to wait between comm ands . The SR510 has a command input buf f er of 256 character s and pr ocess es the commands in the order r eceived. Likewise, t he SR510 has an output buf fer (for each interfac e) of 256 characters.

In general, if a command is sent without paramet er s, it is inter pr eted as a request to read the status of the associated f unction or setting. Values returned by t he SR510 are s ent as a string of ASCII char act ers t erminated usually by car r iage retur n, line-feed. For example, after the above command is sent , the following read commands would generate the r esponses s hown below.

Command Response from t he SR510 G <cr> 5<cr><lf>

T 1 <cr> 4<cr><lf> P <cr> 45.10< cr > < lf>

The choice of ter m inat ing characters sent by the SR510 is determined by which interfac e is being used and whether t he 'ec ho' feat ur e is in use. The term inating sequence f or the GPIB interf ace is always <cr>< lf > (with EOI). The default sequenc e for RS232 is <cr> when the echo mode is off, and <cr> < lf> when the echo mode is on. The term inating sequence f or the RS232 interface may be changed using the J comm and.

A command t o the SR510 consists of one or two command letters, arguments or parameters if necessary, and an ASCII carriage ret ur n (<cr>) or line-feed (<lf > ) or both. The different part s of the command do not need to be separated by spaces . If spac es are included, they will b e ignor ed. I f more t han one paramet er is required by a command, the param et ers m ust be separated by a comma. Examples of commands ar e:

G 5 <cr> set the sensitivity to 200 nV T 1,4 <cr> set the pre filter to 30 mS F <cr> read the reference frequency P 45.10 <cr > set phase shift to 45. 10° X 5,-1. 23E-1 < cr> set por t X5 to -0.123 V

Multiple commands m ay be sent on a single line. The commands m ust be separ at ed by a semicolon (;) character. The commands will n o t be exec u ted until the ter m inating car r iage return is sent.

Note that the terminating char act er s are sent with each value retur ned by t he SR510. Thus, the response to the command string G;T1; P< cr > while using the RS232 non-echo mode would be 5<cr>4<cr>45.10<cr>.

Front Panel S ta tus LED's

The ACT LE D f lashes whenever t he SR510 is sending or receiving charact er s ov er the comput er

interfaces. The ERR LED f lashes whenever an er r or has

occurred, s uch as, an illegal command has been received, a par am et er is out of range, or a communicat ion buff er has exceeded 240 character s . This LED flashes for about thr ee seconds on power-up if t he batt er y voltage is insufficient t o r et ain pr evious instr um ent settings.

The REM LED is on whenever t he SR510 is program m ed to be in the remote state.

RS232 Echo and No Echo Operation

In order to allow the SR510 to be operat ed from a term inal, an echo f eature has been included which causes the unit t o echo back commands rec eived over the RS232 port . This feature is enabled by setting switch 6 on SW2 to the DOWN position. In

this mode, the SR510 will send line-feeds in addition to carr iage returns with each value retur ned and will a ls o s end the prompts 'OK>' and '?>' t o indicate that the pr evious com m and line was either processed or contained an error. Operat ing t he SR510 fr om a terminal is an ideal way to learn the commands and r es ponses bef ore attem pt ing t o program a computer to contr ol the SR510. When the unit is controlled by a computer , the ec ho featur e should be turned off t o prevent t he s ending of spurious characters which the comput er is not expecting.

Try-Out with an ASCII Terminal

Before at t em pting any detailed program m ing with the SR510, it is best to try out the commands using a terminal. Connect a term inal with an RS232 port to t he RS232 connector on t he rear panel of the SR510. Set the baud rat e, parit y, and

stop bits t o match the term inal by setting SW2 per the switch set t ing t able given on page 7. The echo mode should be enabled (switch 6 DOWN).

After setting SW2 and connecting the term inal, hold down the REL key whi le turning the unit on. This causes the SR510 to assum e its def ault settings so t hat t he following discussion will agree

with the actual re sponses of t he SR510. The ACT and ERR LED's on t he front panel will f la s h for a second and the sign-on m essage will appear on the terminal. Following the m es sage, the prom pt 'O K> ' will be displa y e d. This indicat e s that th e SR510 is ready to accept commands .

to the terminal. Now read the gain using the sensitivity r ead

command, G<cr>. The response should be 24 meaning that the sensitivity is at the 24th setting or 500 mV. Change the sensit ivity by typing G19<cr >. The sensitivity should now be 10 mV. Check the fr ont panel to mak e sure this is so.

The output of the lock- in is read by typing the command, Q1<c r >. The response is a signed floating point number with up t o 5 significant digits plus a signed exponent. Change the gain to 10 uV using the G10 com m and. The response to the Q1 command will now be sim ilar to the pre v iou s o n e except t hat the exponent is differ ent.

Attach a DC voltmeter to the X6 output on the rear panel. The range should allow for 10V readings.

The voltage at t he X6 output can be set using the X6 command. Type X6,5.0<cr> and the X6 output

will change to 5.0V. To read this back to the terminal, just type X6<cr>. When setting the X6

voltage, t he volt age m ay be sent as an integer (5), real (5.000) , or floating point ( 0. 500E1) num ber.

Now connect the X6 out put to the X1 input (also on the rear panel). X1 through X4 ar e analog input ports . To read the voltage on X1, si mply type X1<cr>. The response 5.000 should appear on the terminal. The analog port s X1 through X6 can be used by your computer to read outputs of other inst r um ent s as well as to control other laboratory par am eters.

At this point, the user should experiment with a few of the comm ands. A detailed command list follows.

Type the lett er 'P' followed by a carriage ret ur n (P<cr> ). The SR510 responds by sending to t he term inal the char acters 0.00 indicating that t he phase is set to 0 degrees. In general, a command with no argument s or param et ers reads a sett ing of the unit. To set the phase to 45 degrees, type the comm and, P45<cr >. To see that the phase did change, use the SELECT k ey on t he front panel to display the phase on the REFERENCE DIGITAL DISPLAY. Typing the phase read

command, P< cr>, will now return the s tr in g 45 .00

SR510 Command List

The first letter in each command sequenc e is the command. The rest of the sequence consists of paramet er s. Multiple parameter s ar e separated by a comma. Those param eters shown in {} are optional while those without { } ar e required. Variables m and n represent integer parameters while v represent s a real number. Parameter s m and n must be expressed in integer f ormat while v may be in integer, real, or floating point f ormat .

The F command r eads the refer ence frequency. For example, if the ref erence frequency is 100 Hz,

the F comm and retur ns the string "100. 0". If the refer ence frequency is 100. 0 kHz, the string "100.0E+3" is ret ur ned. The F command is a read only command.

G {n}

If n is included, the G command sets t he gain (sensitivity) . If n is absent, the gain setting is returned.

A {n}

If n is "1", the A command causes the auto offset routine to r un. Every time an "A 1" command is

received, t he aut o offs et function is executed. If n is "0", then the auto offset is tur ned off. If n is absent, then the auto offset st atus is returned. Note that if the manual offset is on, an "A 1" command will turn o ff the m anual offset befor e executing the aut o offs et funct ion.

B {n}

If n is "1", the B command sets the bandpass filter in. If n is "0", the bandpass filter is taken out. If n

is absent, t hen the bandpass f ilter status is returned.

C {n} If n is "1", the C command sets the reference LCD display to show the phase setting. If n is "0", the

LCD will display the refer enc e frequency. If n is absent, the paramet er being displayed (frequency or phase) is returned. Note that the P and F commands ar e used to read the act ual values of the phase and fr equenc y.

D {n} If n is included, the D command s ets the dynamic reserve. If n is absent, the dynamic reserve

setting is ret ur ned.

n Sensitivity 1 10 nV 2 20 nV 3 50 nV 4 100 nV 5 200 nV 6 500 nV 71 µV

82 µV 95 µV 10 10 µV 11 20 µV 12 50 µV 13 100 µV 14 200 µV 15 500 µV 16 1 mV 17 2 mV 18 5 mV 19 10 mV 20 20 mV 21 50 mV 22 100 mV 23 200 mV 24 500 mV

Note that sensit ivity sett ings below 100 nV are allowed only when a pre-amplifier is connect ed.

n Dyn Res 0LOW 1NORM 2 HIGH

Note that not all dynamic reserv e settings ar e allowed at every s ensit ivity.

E {n}

If n is "1", the E command turns the output expand on. If n is "0", the expand is turned off. If n is

absent, the expand status is returned.

The H command reads t he pre-ampli f i er stat us. If a pre-am plifier is connect ed, a "1" is returned,

otherwise, a "0" is r et urned. The H command is a read only command.

I {n} If n is included, the I command sets t he remotelocal st atus. If n is absent, the remote-local stat us

is returned.

n Status 0 Local: all front panel keys ar e oper ative 1 Remote: front panel keys ar e not

operative. The display up key re t urns the status to local.

20 Quad Down 21 Select Display (f/ phase) 22 Sensitivity Up 23 Sensitivity Down 24 Dyn Res Up 25 Dyn Res Do wn 26 Display Up 27 Display Down

2 Lock-out: front panel keys are not

operative. No key retur ns the status to local. Another I command is needed t o return to loc a l.

When using the GPI B interface, the REN, LLO, and GTL comm ands ar e not implement ed. The I command is used by bot h interf aces to set the remot e- local status.

J {n1,n2, n3, n4}

The J command sets the RS232 end-of-record character s sent by the SR510 to those specif ied

by the ASCII codes n1- n4. If no argument is included, t he end- of-r ec or d sequence r eturns to the default ( a carriage return) , other wise, up to four char acters may be specified. The end- ofrecord r equired by the SR510 when receiving commands is not affected.

K n The K command simulat es a front panel key press. The effect is exactly the same as press ing

the selected key onc e. The paramet er n is required.

nKey 1 Post Time Constant Up 2 Post Time Constant Down 3 Pre Time Constant Up 4 Pre Time Constant Down 5 Offset Up 6 Offset Down 7 Zero Phase (Simultaneous 90¡ Up and

Down) 8 Line Notch Filter 9 Bandpass Filter 10 Line X 2 Notch Filter 11 Relative (Auto Offset) 12 Offset (On/Off) 13 Expand 14 Local (Display Up when REMOTE) 15 Reference Trigger M ode 16 Reference Mode (f/2f) 17 Degrees Up 18 Degrees Down 19 Quad Up

L m {,n}

The L command set s and reads the status of the line notch filters. If m is "1", then the 1X line

notch is selected, if m is "2", the 2X line notch is selected. The par am et er m is required. If n is "1", the L command sets the selected f ilter in. If n is "0", the select ed filter is t aken out. If n is absent, the status of the selected filter is ret urned.

M {n} If n is "1", the M command sets the reference mode to 2f. If n is "0", the reference mode is set

to f. If n is absent, the reference mode is returned.

N {m}

If m is "1", the N command sets the ENBW to 10 Hz. If m is "0", the ENBW is set to 1 Hz. If m is

absent, the ENBW setting is retur ned.

O {n} {,v}

If n is "1", the O command turns the offset on. If n is "0", the offset is tur ned off. If n is absent, the

offset st at us (on or off) is returned. (The value of the off s et is read using the S and Q commands.) If n is included, then v may also be sent. v is the offset value up to plus or minus full scale in units of volts. For example, to offset half of full scale on the 100 µV sensitivity, v should be "50. 0E-6" or an equivalent value. However, if the sensitivit y is then changed to 200 µV, the off s et is now half of the new full scale or 100 µV. When the sensitivity is changed, the offset is retained as a const ant fract ion of full scale rat her than as a voltage refer r ed to the input. The expand funct ion will, o n the other hand, preser v e the value of the offset as an input refer r ed voltage. Once a value of v is sent, the of f set may be turned off and on without losing the offset value by using the O command without the v par am eter. Note that if the auto offset is on, an "O 1" command will t u rn the au to offset of f and tur n the manual offset on without changing the actual offset value.

P {v}

If v is absent, the P command returns the phase setting f r om -180 to +180 degrees. When v is

included, t he phase is set to the value of v up to ±999 degrees.

The Q comm and retur ns the output reading in units of volts . For an input signal of 50 µV on a full scale sensitivity of 100 µV, the Q com m a n d will retur n the string "50.00E-6". The parameter read

is the same as that being shown on the output display and can be changed with the S command.

R {n}

If n is included, the R command s ets the reference input t ri gger m ode. If n is absent, the trigger

mode is retur ned.

n Mode

0 Positive

1 Symmetric

2 Negative

S {n}

If n is included, the S comm and select s the paramet er shown on the analog meter and output digital display as well as the out put BNC. If n is absent, the paramet er being displayed is returned.

n Display

1 Offset

2Noise

T m {,n}

The T command sets and reads the stat us of the tim e const a nt s. If m is "1", the pre time constant

is selected, if m is "2", the post time constant is selected. The par am et er m is required. If n is included, t he T c ommand set s the select ed time constant . If n is absent, the setting of the selected time const ant is retur ned.

n Pre Time Constant ( m=1)

11mS

23mS

310mS

430mS

5 100mS

6 300mS

71S

83S

910S

10 30 S

11 100S

n Post Time Constant ( m=2)

0 none

1 0.1 S

21 S

U m {,n}

The U command set s and reads the unit's ROM calibration bytes. m is the address offset of the

byte, 0- 255. If n is absent, the value of the addressed calibration byt e is r et ur ned. If n is included, t he addr ess ed calibrat ion byt e is set to the value of n, 0-255. The new value will be in effect unt il the power is t urned off or a reset command is issued. Use of this command is not recommended.

V {n}

If n is included, the V comm and sets the GPIB SRQ (s er vice r equest ) mask to t he value n. If n is

absent, the value of the SRQ mask is returned.

W {n}

The W command s et s and reads the RS232 character wait interval. If n is included, the SR510

will wait n*4 mS between charact er s sent over the RS232 interface. This allows slow comput er interfac es t o keep up. n can range from 0 to 255. If n is absent, the wait value is ret urned. The wait interval is set t o 6 on power-up.

X n {, v} n designates one of t he 6 general purpose analog ports locat ed on t he rear panel. If n is 1,2,3, or 4,

the X comm and will r e turn the v o ltage on the designated analog input por t (X1-X4) in volts. If n is 5 or 6, then v may also be sent. If v is included, the designated analog output por t (X5 or X6) will be set to v volts where v has the range -10.24V to +10.24V. If v is absent, the output value of the selected port is retur ned. On power-up, port X5 is the rat io out put. An "X 5" command will read the ratio output. An "X 5" command with the par ameter v will set port X5 to v v o lts, overrid in g the r a tio outp ut. Port X5 will retur n to the ratio output on power- up or reset.

Y {n}

The Y command reads the status byte. (See below for a definition of t he Status Byt e.) n

designates one bit, 0- 7, of the status byt e. If n is included, t he designat ed bit of t he status byte is retur ned. The bit which is read is then reset. If n is absent, t he value of the entire byt e is returned and all status bits ar e then reset. This status byte may also be read over the GPIB using the ser ial poll command.

The Z command caus es an int er nal reset. All settings r et ur n to their default values. The ERR

LED will be on for about 2 seconds to indicate that the stor ed instrum ent set t ings are being ignored. If the RS232 echo mode is on, the sign-on message is sent over the RS232 interf ace.

Status Byte

Overload. This bit is set if there is a signal

overload. This can happen when the sensit ivity is too high, t he dynam ic reserve is too low, the offset is on, or the expand is on. Overloads on the general purpose A/D inputs or t he ratio out put are not detected.

The SR510 maintains an 8-bit st at us r egist er which the user may r ead to obtain informat ion on the unit's s t atus. The status byt e may be read in two ways: by sending the Y command, which retur ns the value of the byte in ASCII coded decimal, or, when using the G PIB, by perfor m ing a serial poll. The retur ned st atus byt e reflect s all of the status conditions which have occurred since the last t ime the byte was read. After the status byte has been read, it is cleared. Thus, the status byte should be read initially to clear all previous conditions (especia lly aft er a power up or after settings have been changed) .

The definitions for each bit of t he status byte are given below:

Bit 0 Busy. When this bit is set, it indicates the SR510

has unprocessed com m ands pending on its command queue. For RS232 communicat ions, this bit is always high since the Y command its elf will be an unprocessed comm and. This bit is not reset when read but only when ther e ar e no pending commands. Since the SR510 buff er s incoming commands, it is not necessary to read this bit befor e sending each com m and. Commands received while t he SR510 is executing a previous comm and ar e stored unt il all previously received comm ands have been ex ecut ed.

Bit 5 Auto Offset Out of Range. This bit is set if the

auto off s et function cannot zer o the out put because the out put exceeded 1.024X f ull scale.

Bit 6 SRQ. This bit is high if the SR510 has generated

an SRQ on the GPIB interface. This bit is reset after the SR510 has been serial polled. This bit is set only for stat us reads via a serial poll, ie., Bit 6 always zero for t he RS232.

Bit 7 Command Error. This bit is set when an ill egal

command st r ing is received.

Errors

Whenever a 'par am et er out of range' or an 'unrecognized comm and' er r or occur s, the appropriate status bits are set and the ERR LED

flashes. I n addition, any com m ands remaining on the curr ent comm and line (up to the next <cr>) are lost. The ERR LED will also light if any of the

internal comm unicat ion buffers overflows. This occurs when 240 charact ers are pending on the command queue or out put queue. The ERR LED

will go off as soon as all buffers drop below 200 character s again.

Bit 1 Command Parameter Out of Range. This bit is

set if a paramet er associated with a com m and is not in the allowed range.

Bit 2 No Refe rence. This bit is set when no reference

input is detected, either because the amplitude is too low or the frequency is out of range.

Bit 3 Unlock. This bit is set when the reference

oscillator is not locked t o the referenc e input. If there is no referenc e input, bit 2 (no ref erence) will be set but bit 3 (unlock) may not be.

Bit 4

Reset

The Z command r esets the unit to its default state. The default f r ont panel sett ings are list ed in the DEFAULTS section of t he Guide to Operations.

In addition, t he int erface status returns to LOCAL, the SRQ mask is clear ed, the RS232 charact er WAIT interval is set to 6, and the terminat ing sequence is reset t o the proper def aults.

The command and out put buffers are cleared by the Z comm and. Therefore, it is bad pr actice to use the Z command before all previous commands have been processed and all responses have been received.

Troubl e-Shooting Interface Problems

If you are having difficult y get t ing your comput er to communicat e with t he SR510 look to t he sections on the RS232 and GPIB inter f aces for some tips specific to your particular inter f ac e.

An ASCII term inal is a valuable aid for debugging interfac e pr oblems. You can use it to:

1) bec o m e familiar with the SR510's com m and

structure,

seen Microsof t ' s Interpreted Basic on the IBM PC occasionally send a curly bracket ( ASCII

253) when it was supposed to have sent a carriage ret ur n (ASCII 13) .

2) Your computer's baud rate has been changed and no longer matches t he SR510's baud rate.

3) The initial com m and sent to t he SR510 was invalid due to a garbage char ac t er left in the command queue f r om power-up, or, the first character in you com puter' s UART is garbage, also due to power-up. It is good practice to send a few carr iage returns to t he SR510 when your program begins, and have y our program clear- out its UART at the start of your program.

2) see GPI B bus transact ions by us ing the GPIB echo mode,

3) eavesdrop on t r ans act ions when using the RS232 interface,

4) substit ut e a hum an for the SR510 by using a null modem cable ( to make the DTE a DCE ) and attaching t he term inal to the port to which you would normally have connected t he SR510. This allows you to tes t your program ' s responses t o inputs which you pr ovide fr om the terminal.

Common Hardware Problems include:

1) The RS232 or GPIB cables ar e not properly attached.

2) The configuration switches for the RS232 character ist ics or GPIB addres s ar e not set correct ly (Make sur e the RS232 echo is off when using the RS232 interface with a computer . The GPI B with RS232 echo mode should be off when not debugging t he G PI B interface.)

3) Your computer requires an RS232 control line to be asserted, but your cable does not pass it between the SR510 and the com put er, or, your comput er is not ass erting the DTR line on the RS232.

Commo n Software Problems incl ud e:

1) You have sent t he wrong c ommand t o ask for data fr om the SR510. Your progr am will wait forever for a response which is not going to come. This m ay not be your fault; we have

4) The SR510 is not sending the corr ec t ' end- ofrecord' marker for your computer. For example, it appear s t hat M icrosoft 's Rev 3.2 FORTRAN on the I BM PC under DOS 2.1 requires two car r iage returns for an end-ofrecord m ar ker. The J command can be used to set the SR510 end-of- r ec ord mar ker to 2 carriage ret ur ns . [The end-of-recor d m arker is that sequenc e which indicates that the response is complet e. Fr om the keyboard, a single carriage retur n is t he end- of-r ec or d marker.]

5) Answers are com ing back f r om the SR510 too fast, over writing t he end- of-r ecor d mark er s, and causing the comput er to hang waiting for a complete res ponse. In this case, the W command can be used to slow down the response tim e of the SR510 prevent ing overwriting.

6) Answers are com ing back f r om the SR510 too slowly due to the W6 default setting f or the character int er val t ime. Use the W command to speed up the trans m ission from the SR510. This can cause problems f or the GPI B interfac e if the echo mode is on (switch 6 of SW21).

Th e S R510 with t he RS232 Int erf ace

The RS232 is a popular serial interf ac e st andar d for bit s erial communication. Despite t he existence of t he standar d t here are many permut at ions of contr ol lines, baud r at es, and data form at s. If you do not have a lot of experience interfac ing RS232 equipment you should read Appendix B for a description of the RS232 and interfac ing tips.

Data Communications Equipment (DCE)

The SR510 is configured as DCE so that it may be connected direct ly t o a term inal. If the SR510 is to be interfac ed with anot her DCE device, a special cable (somet imes r eferred to as a 'modem' cable) is required. To use the RS232 interf ace you m ust set the s witches in SW2 to match your computer ' s baud rate, par it y, and number of stop bits. Refer to Page 7 for details.

Wait Command

The SR510 normally waits unt il the RS232 'Clear to Send' cont r ol line (CTS) is assert ed bef ore sending character s. However, some comput er s do not set and reset the CTS line, possibly causing the SR510 to send data when t he computer is not ready to read it. The SR510 may be 'slowed down' using the W comm and. Sending 'Wn' causes t he unit to wait nX4 mS before sending each character ov er the RS232 bus. The command W0 s et s the wait inter val to zero and results in the fastest tr ansm ission. The wait interval is set t o 6 (24 mS) on power-up.

Termination Sequences

The default RS232 termination characters ar e sufficient to interface with most computers, howev er, it will o c c as ionally be nec e s s a r y to send special terminating sequences t o f it t he requirement s of some computers. This can be done with the J comm and. The format for the command is:

J {n1,n2, n3,n4}

where n1, n2, n3, and n4 are decimal values between 0 and 255 corres ponding to t he dec imal ASCII codes of t he desired termination char act ers. For instance, if the desired terminat ion sequence is an asterisk, (ASCII 42), t wo carriage ret ur ns, (ASCII 13), and a line feed, (ASCII 10) , the appropriate com m and is:

J 42,13,13,10

Up to four terminating charac t er s may be specified by the J command. If no arguments are sent with the J command, the t erminating sequence r et ur ns to the default ( echo on: <cr>< lf>; ec ho off: <cr>).

The J command does not affect the t erminating character (<cr >) required at t he end of commands received by the SR510. It also does not affect the term inating sequence sent with data over the GPIB interface.

The SR51 0 with the GP IB Interface

For a brief introduct ion t o the GPI B standard, please read Appendix C at the back of this manual. Befor e using t he GPIB interface you must set t he switches in SW1 per the instruct ions on page 7.

GPIB Capabilities

The GPIB capabilit ie s o f the SR510 consist ent with IEEE standard 488 ( 1978) ar e shown in the table below. Also shown are the responses of the SR510 to some standar d c ommands.

Code Function SH1 Sour ce handshake c apabi lity

AH1 Accept or hands hake capabil it y T5 Basic Talker, Serial Po ll, Unaddress ed t o

talk if addressed to listen

L4 Basic Listener , Unaddressed to listen if

addressed to talk

SR1 Ser vice reques t capability PP0 No parallel poll capabil ity DC1 Device Clear capability RL0 REN,LLO, GTL not im plement ed.

'I' command sets Remote-Loc al.

SR510 Response to GPIB Commands Mnemonic Command Response

DCL Device Clear Same as Z com m and SDC Selected Same as Z com m and

Device Clear

SPE Ser ial Poll Send St at us Byt e,

Enable & clear status byte

If a G command is sent requiring an answer of 24 (sensitivity = 500 m V), the SR510 would respond with the str ing

24*<cr><cr><lf>

Because the SR510 can be controlled by an RS232 interface as well as the GPI B, the remotelocal functions are not standard. There is no local with lock out stat e. When in the local state, remot e commands ar e processed, even without the REN command being issued. This is because

the RS232 interfac e has no pr ovision for bus commands and r em ote com m ands over the RS232 interface would never be enabled.

Serial Poll s and Service Requests

The status byt e sent by the SR510 when it is serial polled is the same stat us byte which is read using the Y comm and (except for bit 6, SRQ). Of course, when t he SR510 is serial polled, it does not encode the stat us byte as a decimal num ber. The SR510 can be programm ed t o gener ate a service request ( SRQ) to the G PIB controller ever y time a given status condition occurs. This is done using the V{n} com m and. The mask byte, n (0-

255), is t he SRQ mask byte. The mask byte is always logically anded with the st atus byte. If the result is non-zer o, the SR510 generates an SRQ and leaves the stat us byte unchanged until the controller per f or m s a serial poll to determine the cause of t he service request . When the unit has been serial polled, t he st atus byt e is reset to reflect all of the status conditions which have occurred since t he SRQ was gener at ed.

For example, if we want to generat e an SRQ whenever there is an over load or unlock condition, we need an SRQ mask byte equal to 00011000 binary, or 24 dec imal ("V24" com m and). The byte 00011000 binary corres ponds t o the status byte with the 'no referenc e' and ' unlock' stat us bit s set. If an overload occurs, then an SRQ will be generated. The ser ial poll will return a stat us byte showing SRQ and overload. If an unlock condition occurs bef or e the serial poll is concluded, another SRQ will be generated as soon as t he serial poll is finished. A second serial poll will reflect t he unlock condition.

GPIB with RS232 E cho Mode

It is sometimes us ef ul when debugging a GPIB system to have some way of monitoring exactly what is going back and fort h over the bus. The SR510 has the capability t o echo all characters sent and received over the GPI B to its RS232 port. This mode of operation is enabled by setting switch 6 of SW1 t o t he DOWN position. The baud

rate, stop bits, and parit y of the RS232 port are still s e t by SW2. Of course, the RS232 port

operates at much lower speeds t han t he GPIB and will slow down the GPI B data rate in this mode. (Use the W0 command t o allow the RS232 interfac e t o run at full speed, other wise, the G PIB transactions may take so long that the controller can hang.) During act ual use, this m ode should be disabled.

Th e S R510 with BOTH Interfaces

If both inter f aces are connect ed, comm ands may be received fr om either inter f ace. Responses are always sent to t he sour ce of the request (except in GPIB echo mode) . It is unwise to send commands from the two interfaces at the same time since the character s from differ ent sour ces can bec om e interleaved on the com m and queue and r es ult in 'unrecognized comm and' er r or s.

Any SRQ generated by t he 'no ref erence, ' unlock', 'overload', and 'auto over-range' conditions will also reset t he corresponding bit in t he SRQ m ask byte. This is to prevent a const ant err or condition (such as no referenc e applied to t he input) from continually inter r upt ing t he controller. W hen such an SRQ occurs, the contr oller should change some param et er so as to solve the problem, and then re- enable the SRQ mask bit again using the V command.

The Loc k-in Tec hnique

A Measurement Examp le

The Lock-in technique is used to detect and measure ver y small ac signals. A Lock-in amplifier can make accur at e measurem ent s of small signals even when the signals are obscured by noise sources which may be a t housand t im es larger. Essentially, a lock- in is a filter with an arbitrar ily narrow bandwidth which is t uned t o t he frequency of the signal. Such a filter will reject m o s t unwanted noise to allow the signal to be measured. A typical lock-in application m ay require a center frequenc y of 10 KHz and a bandwidth of 0. 01 Hz. This 'filter' has a Q of 106 well beyond the capabilit ie s o f passiv e ele c tronic filters.

In addition to f ilter ing, a lock-in also provides gain. For example, a 10 nanov olt s ignal can be amplified to produce a 10 V out put-- a gain of one billion.

All lock-in measurem ents share a few basic principles. The technique requires t hat the experiment be ex cited at a f ixed frequency in a relatively quiet part of the noise spect r um. The lock-in then detects the respons e from the experiment in a ver y narrow bandwidth at the excitation fr equenc y.

Applications include low level light detection, Hall probe and str ain gauge meas ur em ent, micro-ohm meter s, C-V testing in semiconductor research, electron spin and nuclear m agnet ic res onance studies, as well as a host of other situat ions which require the det ec t ion of small ac signals.

Suppose we wish to measur e the res istanc e of a mater ial, and we have the rest r ict ion that we must not dissipate very m uch power in the sample. If the resist ance is about 0.1Ω and the current is

restricted to 1 µA, then we would expect a 100 nV signal from t he resistor . There ar e many noise signals which would obscure t his sm all signal -60Hz noise could easily be 1000 times larger , and dc potentials fr om dissimilar met al junctions could be lar g e r still.

In the block diagram shown below we use a 1Vrms sine wave generat or at a frequency wr as

our ref er ence s ource. This source is curr ent limited by the 1 MΩ resistor to prov ide a 1 µA ac

excitation to our 0.1Ω sample. Two signals are prov ided to the lock-in. The

1VAC reference is used to tell the lock-in the exact frequency of the signal of inter est. The lock-in's Phase-Lock Loop (PLL) c ircuit s will track this input signal frequency without any adjustm ent by the user. The PLL out put may be phase shifted to provide an output of cos(wrt+Ø).

The signal from t he sam ple under test is amplified by a high gain ac coupled differential amplifier. The output of this am plifier is m ultiplied by the PLL output in t he Phase-Sensit ive Detect or ( PSD). This multiplication shif t s each frequency component of the input signal, ws, by the

refer ence frequency , wr, so that the output of the PSD is given by:

Vpsd = cos(wr+Ø) cos(wst)

= 1/2 cos[(wr + ws)t+Ø] +

1/2 cos[ ( wr - ws)t+Ø]

The sum fr equency com ponent is attenuated by the low pass filter, and only those diff er ence frequency c om ponent s within t he low pass filter 's narrow bandwidth will pass thr ough t o t he dc amplifier. Since the low pass f ilter c an have t im e constant s up t o 100 seconds, the lock-in can reject noise which is more t han .0025 Hz away from the refer ence frequency input.

For signals which are in phase with t he r ef erence, the phase cont r ol is usually adjusted for zer o phase differ ence bet ween t he signal and the refer ence. This can be done by maximizing the output signal. A m or e sensit ive technique would be to adjust t he phase to null the signal. This place s the referen c e os c illa tor at 90 degr ees with respect to the signal. The phase cont r ol can now be shifted by 90 degr ees to maximize the signal. Alternatively, since t he phas e cont r ol is well calibrated, t he phase of t he signal can be measured by adding 90 degrees t o the phase setting which nulls the signal.

single pole f ilter is 1 /4RC. The o utput will c o n v e r g e exponentially t o t he final value with a 10 second time const ant . If we wait 50 seconds, the out put will have come to within 0.7% of its final value.

The dynamic reser ve of 60 dB is required by our expe c tation that the no is e will b e a thousand times larger than t he s ignal. Additional dynamic reser v e is available by using the bandpass and notc h filters.

A phase-shift er r or of the PLL tracking circuits will cause a measurem ent error equal to the cosine of the phase shift error. The SR510’s 1° phase accu racy will no t make a s ig n ificant c on tribution to the measur em ent err or.

Specifications for the Example Measurement Specification Value Error

Full Scale Sensitivity 100 nV Dynamic Reserve 60 dB Reference Fr equency 5 kHz Gain Accuracy 1% 1% Output Sta b ility 0. 1 % /°C 1% Front- End Noise < 7 nV/√Hz 1.2% Output Tim e Const ant > 10 S 0. 7% Tota l RMS Error 2%

Understanding the Specifications

The table below lists som e specif icat ions for the SR510 lock-in amplifier. Also listed are the error contribut ions due to each of these it em s. The spec ificatio n s will allow a me as u rement with a 2% accuracy t o be made in one minute.

We have chosen a ref erence frequency of 5 kHz so as to be in a relatively quiet part of the noise spectrum . This frequency is high enough to avoid low frequency '1/ f ' noise as well as line noise. The frequency is low enough to avoid phase shifts and amplitude error s due t o the RC time constant of the source im pedance and t he cable capacit ance.

The full-scale sensitiv it y of 100 nV m atches t he expected signal from our sample. The sensitivity is calibrated to 1%. The instrum ent's out put sta b ility also a ffects the m ea s u rement a c c uracy. For the r equired dynamic reserve, the output sta b ility is 0. 1 %/°C. F or a 10°C temperat ure change we can expect a 1% error .

A front - end noise of 7 nV/√Hz will manife s t itself as a 1.2 nVrm s noise after a 10 second low-pass filter since t he equivalent noise bandwidt h of a

Shielding and Ground Loops

In order to achieve t he 2% accuracy given in this mea s uremen t exam ple , we will have to be careful to minimize the various noise sources which can be found in the laborat or y. (See Appendix A for a brief discussion on noise sources and shield ing) While intrinsic noise (Johns on noise, 1/f noise and alike) is not a problem in this m easur ement, other noise sources could be a problem. These noise sources can be r educed by proper shielding.

There are t wo methods f or connecting t he lock- in to the exper im ent: the fir st method is more convenient, but t he s econd eliminates s pur ious pick-up more eff ect ively.

In the first met hod, the lock- in uses the 'A' input in a 'quasi-diff er ent ial' mode. Her e, the lock- in detects t he signal as the voltage between t he center and out er conduct or s of the A input. The lock-in does not for c e A's shield to ground, rather it is connected to t he lock-in's ground v ia a 10½ resistor . Because the lock-in must sense t he shield voltage (in order t o avoid t he large gr ound loop noise between the experiment and t he lockin) any noise pickup on the shield will appear as noise to the lock- in. For a low impedance source

(as is the case here) the noise picked up by the shield will also appear on the cent er c onduct or. This is good, because the lock- in's 100 dB CMRR will reject m o s t of this common mode noise. However, not all of t he noise can be rejected, especially the high fr equenc y noise, and so t he lock-in may overload on t he high sensitivity ranges.

Quasi-Differ ential Connection

The second method of connecting the experiment to the lock- in is called the 'true- diff er ential' mode. Here, the lock- in uses t he differ ence bet ween the center conduc t or s of the A & B inputs as the input signal. Both of the signal sources are s hielded from spurious pick-up.

With either m ethod, it is important to minimize both the comm on mode noise and the common m ode signal. Notice that t he signal source is held near ground potent ial in both cases. A signal which appears on both t he A & B inputs will not b e perfect ly cancelled: the common mode rejection ratio (CMRR) spec ifies t he degr ee of cancellation. For low frequencies t he CMRR of 100 dB indicates that the comm on mode signal is canceled to 1 part

in 105, but t he CMRR decreases by about 6 dB/octave ( 20 dB/ Decade) s t arting at 1KHz. Even

with a CMRR of 105, a 10 mV common mode signal behaves like 100nV differential signal.

True-Diff er ent ial Connection

There are som e additional considerat ions in deciding how to operat e the lock-in am plifier:

Dynamic Reserve (DR) is the r atio of the largest noise signal that t he lock-in can tolerat e bef ore

overload to t he full scale input. Dynamic reser v e is usually expressed in dB. Thus a DR of 60 dB means that a noise source 1000 tim es larger than a full scale input can be present at the input without aff ecting the measurement of the signal. A higher DR results in a degraded output s t ability since most of the gain is DC gain after the phase sensitive detect or . In general, the lowest DR which does not cause an overload should be used.

The Current Input has a 1 kΩ input impedance and a current gain of 106 Volts /Amp. Cur r e nts

from 500 nA down to 100 fA full scale can be measured. The impedanc e of the signal sourc e is the most important factor to consider in deciding between voltage and curr ent measurements.

For high source impedances, (>1 MΩ) or small current s, use t he current input. Its relatively low

impedance greatly r educes t he am plitude and phase error s caus ed by the cable capacitancesource impedance t ime c onst ant. The c able capacitance should stil l be kept sm all to m inimize the high frequenc y noise gain of t he current preamplifier.

For moder at e sour c e impedances or larger current s, t he voltage input is prefer r ed. A small value resistor m ay be used to shunt the sour ce. The lock-in then measur es t he volt age across t his resistor . Select the resistor value t o keep the source bias voltage sm all while providing enou gh signal for the lock- in to measure.

The Auto-Tracki ng Bandpass Filter has a Q of 5 and follows the ref er ence frequency . The

passband is theref or e 1/ 5 of the reference frequency. The bandpass filter can provide an additional 20 dB of dynam ic r eser ve for noise signals at frequencies out s ide the pass band. The filter also impr oves t he harmonic r eject ion of the lock-in. The second har m onic is att enuated an additional 13dB and higher harm onics ar e attenuat ed by 6 dB/octave m ore. You may wish to use the bandpass f ilter and select a low dynamic reserve sett ing in order to achieve a better output sta b ility. Sinc e the pro c es s o r can only set the bandpass filter' s center frequency to within 1% of the ref erence fr equenc y, this f ilter can contribute up to 5° of phase shift error and up to 5% of amplitude error when it is used. In addition, the

bandpass filter adds a few nanovolts of noise to the fr ont end of the instrument when it is in use.

Line Notch Fi l ters should be used in most mea s uremen t situa tions. The filter s will re je c t

about 50 dB of line frequenc y noise ( about a factor of 300). If your reference frequency is one oct ave away, then t hese filters will in troduce a 10° phase shift er r or, and a few percent amplitude err or. Their effec t on your signal is negligible if your refer ence frequency is mor e than t wo octaves away.

The frequency ra nge of t he SR510 lock-in amplifier extends from 0.5Hz to 100KHz. No

additional cards ar e required for the instr um ent to cover its f ull frequency range. The SR510 can be used to detec t a signal at the reference fr equenc y or at twice the reference frequenc y t o allow for convenient measur em ent of t he harmonic of the signal.

Noise measurem ent is a feature whic h a llo ws direct meas ur em ent of the noise density of the

signal at the ref er enc e frequency. This is a useful featur e to assess at what frequency y ou should run your exper iment.

Output Fil t er s can have one pole (6 dB per octave) or two poles (12 dB/ octave). A two-pole

filter pr ovides a signal to noise improv em ent over a single-pole filter due to it s st eeper roll off and reduced noise bandwidth. Single-pole filters ar e prefer r ed when the lock-in is used in a servo system to avoid oscillation.

In many servo applications, no output filtering is needed. In this case, the SR510 may be m odified to reduce t he output time constant to about 20 µS. Contact t he factor y for details.

Ratio Capability allows the lock-in's output to be divided by an external voltage input. This f eat ur e

is important in ser vo applications t o m aintain a constant loop gain, and in experiments to normalize a signal to the excit at ion level.

Computer I nt er f ace allows a comput er to control and to recor d data from the instr ument. This is the single most important feature for extending the

lock-in's capabilities and it' s us ef ul lifetime. Measurem ent s which are im pr act ical without a computer becom e s imple when a comput er is used to coordinat e var ious par t s of the experiment.

The Inter nal Oscill at or pr ovides a refer ence source fo r t h e loc k -in. This allo ws the lock -in's

frequency to be set without an additional signal generator . It also provides a sine wave to be used as the signal stimulus in an experiment. The frequency m ay be set via the computer interface as well as manually.

SR510 Block Diagram

Several new concepts are used to simplify the design of SR510 lock-in amplifier . I n addition to implementing recent adv ances in linear integr at ed circuit technology, the instrument was designed to take full advantage of its microprocessor controller to improve perfor mance and to reduce cost.

As an example of the new techniques used in the SR510, consider the har m onic reject ion problem . Previously, lock-in ampl if iers used a PLL with a square wave output . The Fourier com ponent s of the square wave cr eat ed a serious problem -- t he lock-in would respond t o signal and noise at f , 3f, 5f,. ad inf initum . Quite often, one component of this picket f ence of frequencies would land on

some noise source, giving a spur ious res ult. To overcome t his difficulty designers employed tuned amplifiers or het er ody ning techniques. All of t hese 'fix-ups' had dr awbacks, including phase and amplitude error s , sus cept ibilit y to drift, and cardswapping to change f r equenc ies.

In contr ast, the SR510 detect s the signal by mixing a refer ence sine wave in a precision analog multiplier. Because of t he low harmonic content of this s in e wav e , the in s trum e nt is in s en s itive t o harmonics. This approac h has eliminated t he difficulty, per f ormance c om pr om ises, and cost of the older tec hniques.

The Signal Channel

The instrument has both current and voltage inputs. The cur r ent input is a virtual ground, and the 100 MΩ voltage inputs can be used as singleended or tr ue differential inputs.

There are t hr ee signal filters. Each of thes e filters may be switched 'in' or 'out' by the user. The first filter is a line notch f ilter. Set to either 50 or 60 Hz, this filter pr ov ides 50 dB of rejection at the line frequency. The second filter pr ov ides 50 dB of rejection at t he first harmonic of the line frequency. The third filter is an auto-track ing bandpass f ilter with a center frequency tuned by the micr oprocessor to the frequency of the signal. These three f ilter s eliminate most of the noise from the signal input befor e the signal is amplified.

A high-gain ac amplifier is used to amplify the signal before enter ing the phas e sensit ive detector . The high gain which is available fr om this program m able amplifier allows the lock-in t o operate with a lower gain in its dc amplifier. This arrangem ent allows high stability oper ation even when used on the most sensitive ranges .

Refer ence Chann el

The processor c ont r olled ref er ence input discriminator c an lock t he instr ument's PLL to a variety of refer ence s ignals. The PLL can lock to sine waves or to logic pulses with virtually no phase error . The PLL output is phase shift ed and shaped to provide a pr ecision sine wave to the phase sensitive detect or .

Phase S ensitive Det ector

The Phase Sensitive Detector is a linear multiplier which mixes the amplified and filter ed signal wit h the ref erence sine wave. The difference frequency c om ponent of the multiplier's out put is a dc signal that is propor t ional to the amplitude of the signal. The low-pass filter which follows can reject any frequency components which are more than a fraction of a Hertz away from the signal frequency.

DC Amplifier and System Gain

A dc amplifier amplifies the out put of the low pass filters. The tot al system gain is the product of t he ac and dc amplifier gains. The partit ioning of t he system gain between t hese two amplifiers will affect th e sta b ility and dynamic reser ve of the

instrument. The output is most stable when most of the gain is in the ac amplifier, however, high ac gain reduces the dynam ic r eser ve.

For the m ost demanding applications, the user may specify how t he system gain is partitioned. However, with pref ilter s t hat are able t o provide up to 100 dB of dynamic reserv e, and with chopper sta b iliz e d d c a mplifi e rs, m o s t us e rs will not b e concerned with just how the system gain is allocated.

A Microprocesso r Based Design

The instrument was designed to take full advantage of it s micropr ocessor controller. This approach provides sever al key advantages... The instrument may be interfaced to a laboratory computer over the RS-232 and IEEE-488 interfac es. In addition to simply reading data f r om the lock-in, t he c omputer can control all of the instrument settings with simple ASCII c om m ands.

A key featur e of the instrum ent is its four A/D inputs and two D/A outputs. These analog I/O ports m ay be used to read and supply analog voltages to an exper iment or measur ement. All of the input and out put port s have a full scale range of ±10. 24VDC with 2.5 mV resolution and 0.05% accuracy.

Computer control can eliminate set-up errors, reduce tedium, and allow more com plete data recording and post m easur em ent analysis. Also, the comput er can play an active r ole in the data acquisition by adjusting gains, et c. , in r espons e t o changing measurement conditions.

The microproces sor based des ign eliminates many analog component s t o im pr ove perfor m ance, reliability, and reduce cost. Each unit is computer calibrat ed at t he factor y, and calibration constant s ar e placed in the inst r um ent's read-only mem or y . The SR510 has only one-fift h of the analog trimm ing components that are found in older designs.

Creative progr am m ing on the us er's part can extend the inst r um ent's capabilities. Fo r exam ple , the lab comput er can instruct the lock- in to measure t he signal at zero and ninety degrees of phase. Doing so allows both the amplitude and phase of the s ignal of inter est to be measur ed.

Circuit Description

between the t wo transistor s and therefore their gain match and com m on mode rejection.

Introduction

The SR510 Lock-in amplifier is an integr at ed instrument combining state of the art analog design with advanced microproces sor based control and inter f ac es. This discussion is intended to aid the advanced user in gaining a bett er understanding of t he inst r ument.

The SR510 has 8 main circuit areas: t he signal amp lifier, the refe rence os c illa tor, the demod ulator, the analog output and controls, the front panel, the micr opr oces sor , the computer int erfaces, and the power supplies. With the except ion of the front panel and a few pieces of hardware, the entire lock- in is built on a single printed circuit board. Each sect ion is isolated f r om the others as much as possible to prev ent spurious signal pickup. To aid in the location of individual components, the first digit of each part number generally refer s t o the schem at ic sheet number on which it occurs. To help f ind the part on the circuit board, t he parts list includes a location on t he circuit board f or each com ponent .

Signal Amplifier

Assuming the input select or switch is set to a voltage input, t he s ignal is coupled in through capacitors C101 and C102. The input im pedance is set by the 100 MΩ resistors R101 and R102 over the oper at ing frequency r ange. Note that R103 isolates t he signal shields from t he instrument ground forcing the return signal current back along the cable shields. The signal is then applied differ ent ially to t he gat es of Q101. Q101 is a low noise dual JFET. The drain curr ent thr ough R109 is kept constant by 2/2 U101. The other half of U101 maintains a virt ual null between the dr ains of the two transistors and t hus an identical current flows through R110. Any input that would cause a differential between the two drains is amplified by 1/2 U101 and fed back via R112 in such a way as to reduce t hat diff erential. Since the two transist or s ar e at equal and constant cur r ents, their gate- s our ce potentials are c onst ant. Thus , the fed back signal which appears at t he source of the right hand trans istor exactly mat ches the input. Likewise, t his signal will match t he input to the left hand transist or but with the opposit e sign. Resistors R112 and R110 attenuate the fed back signal from t he out put of U101 resulting in a differential input, single ended output , fixed gain of 10 amplifier. P101 adjusts t he current balance

The output of the pr e-amp is scaled by r esist ors R119-R122 and analog switch U103 which mak e up a 1-2-5- 10 attenuat or. The signal is then amplified by 2/2 U102. I nput overload is sensed through diodes D101-D104.

Current Amplifier

When the input select or is set to current, the input to the pre-am p comes from the out put of the current to voltage converter, 1/2 U102. U102 is a low voltage-noise bipolar op amp. Q102 serves as an input buff er to provide low current- noise t o the input. The op amp always maintains a null at the gates of Q102 t hus providing an input impedance of 1KΩ (R128). The input curr ent is convert ed to a voltage by R135 and the op amp. Q103 bootstr aps out the summing junction capacitanc e of Q102.

Notch Filters

U107 is a high Q, line frequency, not ch filter which can be switched in and out by analog switch 1/4 U106. The frequenc y and dept h of the filter can be adjusted with P102 and P103. Resistors R146R149 and switch U108 make up a selectable attenuat or . U118 is a line frequency 2nd harmonic notch filter select ed by 2/4 U106. P104 and P105 adjust the f r equency and depth. The second notch filter has a gain of 3 and its output is scaled by U110 and resistors R156-R159. The s ignal then takes two paths; to invert ing amplifier U111 and to the input of the tracking bandpass filter . U111 has the same gain as the bandpass filter . The output of either U111 or the bandpass f ilter is selected by 3/4 U112 and 4/ 4 U106 and amplified by U113. U114 and U115 provide a last stage of gain and scaling and the f inal output is ac coupled and buffer ed by 4/4 U208.

Band pass Fil t er

The bandpass filter is a t hr ee op amp statevariable active filter . 3/ 4 of U201 make up the three op am ps of the standar d filter. U203, U204, and U205 are analog switches which select t he feedback capacitor s f or the 5 decades of operation. The two halves of U202 are mat ched transconduc t ance am plifiers oper at ing as program m able, volt age controlled, current sources which take the place of t he normal, frequency setting, r esist or s. A voltage proport ional to the

refer ence frequency is conver t ed int o a current by 1/4 U208 and Q201. This current program s the effective "resistance" of the two transconductance amplifiers and thus, tunes the center frequency of the filter to follow the refer ence. The output of the filter is buffered by 4/4 U201. The two remaining op amps in U208 are used to detect signal overloads thr oughout t he am plifier c hain.

Reference Oscillator

The refer ence input signal is ac coupled and buffer ed by U301. R378 isolates the ref erence shield from t he lock- in ground to prevent ground loop currents . 1/2 U303 switches the polarit y of the ref erence reaching com par at or U304. U305 is a retr iggerable one-s hot whose out put indicates a no refer ence condit ion if no com par ator pulses ar e generated f or 3 seconds.

U309 is a dual transconductance am plifier in a triangle VCO configuration. U310 selects the integrating capacit or depending on the frequency range. The VCO frequency is determined by t he program m ing curr ent t hr ough R318 and therefor e by the output voltage of U308. C306 is the phaselocked loop low pass filter which is buff er ed by U308. U307 is a programm able current sour ce used to charge and dischar ge C306. The amount of curr ent available to U307 is determ ined by the VCO control voltage, thus, the trac king rate of the VCO is proport ional to t he VCO frequency. The triangle output is com par ed to a const ant voltage by U314. 1/2 U313 and 1/2 U312 select f or 2f operation. This signal is fed back t o the phase detector U306 t o be compared with the ref erence output of U304. U315 compar es the triangle output with a var iable voltage t o gener at e a square-wave signal phase-shifted fr om the refer ence. The range of this fine phase shift control is -5 to 95 degrees.

The output of U315 serves as the ref erence to a second phase-locked loop. This second PLL uses a similar proport ional tr acking t r iangle VCO. Comparator U329 looks at t he square wave output of the VCO while comparator U328 det ect s the zero cross ings of the triangle output . 1/2 U327 selects one these c om par at ors to feed back to the phase detect or , U316. Since the squar e and triangle output s ar e in quadr at ur e, U327 selects either an in-phase or quadr at ur e relationship between the t wo VCO's. Thus, the out put of the second VCO can be shifted from -5 to 185 deg from the reference.

The triangle output is divided by R363 and R362 before r eaching t r ansconduc t ance am plifier 2/ 2 U322. The amplitude of the triangle input to this amplifier is enough to just s at ur ate the input and provide a sine wave output. 2/2 U325 then amplifies the sine wave befor e it goes to the demodulator. U324 is a com par ator which generates a squar e wave in-phas e with t he sine output. U326 divides the frequency of the squar e wave by 8 and 2/2 U327 selects the fr equency of the square wave chopper .

Demodulator and Low Pass Amplifier

Amplifier U402 and switch U401 select the polarity of the refer ence s ine wave. This allows phase shifts up t o 360 degrees from the referenc e input. The sine wave is ac coupled by U403 and inverted by U404. U405 selects alter nat ing polarities of t he sine wave at the chopper frequenc y, f/ 2 or f/16. This chopped sine wave is then m ultiplied by the output of the s ignal amplifiers by t he analog multiplier U406. The synchronous out put of t he multiplier that c or r esponds to the in-phase signal is a square wave at the chopper frequency. The output is ac coupled by U407 to remove the dc offset of the multiplier. U408 invert s the signal and U405 chops the square wave t o r ecover a dc output. U409 buffer s the chopper output bef ore the first low pass time constant. Op amps U416 and 2/2 U402 make up the first low pass amplifier with relays U411-U415 and U417 selecting t he time const ant . The second low pass amplifier is U419. Analog switch U418 selects the tim e constant and gain. The full scale output of U418 is 5 volts.

Analog Output and Control

The dc output of t he demodulator/ low pass amplifiers is passed to the refer ence input of multiplying DAC U50 2. The DAC is progra mmed with the appropr iate attenuation to calibrate the overall gain of the lock-in. Every gain setting in each dynamic reser ve is calibrat ed independently and the proper attenuat ions ar e stored in the unit's ROM.

A/D's

Analog multiplexer U504 selects t he signal to be digitized by the micropr oces sor . This signal can be either the lock- in out put or one of the four independent analog inputs buffered by U501. These general purpose inputs ar e locat ed on t he rear panel of the instr um ent. The selected signal

is sampled and held on capacitor C502 and buffer ed by 4/4 U508. The A/D conversion is done by successive approximation using comparator U514 to compare the sampled and held signal with known outputs of U505, a 12 bit DAC with a precision refer ence. Note that the out put of U506, an 8 bit DAC is summed with the output of U505. This 8 b it DAC corrects for offse t error s which c a n accumulate as analog voltages pas s t hr ough buffer s, S/H am ps, and compar ators . These offsets are measur ed after each unit is manufact ur ed, and values to c om pensat e for these offsets are placed in the unit's ROM. The polarity of t he offs et-cor r ected 12 bit DAC is set by 2/4 U511 and the SIGN bit yielding 13 bits of resolution fr om -10.24 t o +10.24 v olts.

D/A's

In addition to pr oviding ref er ence v oltages for A/ D conversion, t he DAC output volt age m ay be multiplexed by U507 to one of eight sam ple and hold amplifiers which prov ide analog output and control voltages . The microproc essor r efres hes each S/H amplif ie r every few millise c onds to prevent dr oop. Two of these output s are available as general program m able out put s on the rear panel. Two are used to program the band pass filter and t he refer ence os cillator phase shift. One output is subt r acted from the lock-in output in U508 to provide a variable off set and another is the rm s noise output. Two output s are not used.

Microprocesso r Control

The microproc essor , U701, is a Z80A CPU clocked at 4 Mhz. 16K bytes of firmware are stored in t he ROM, U702. U703 is a 2K byte static RAM, backed-up by a lithium bat t ery. A powerdown standby circuit, Q701, preserves the RAM contents when the power is turned off. The batter y has a life of 5-10 years. The CPU has power-up and power-down r eset s to prevent erroneous execution during turn-on or short sags in the line voltage.

U704 is a 3-channel counter. One channel generates t he baud r ate for the RS232 interface while the other two are used to measur e the frequency or per iod of the refer ence os cillator. U709 provides a gate pulse to count er 0. Multiplexer U708 selects whether t he gate is a single period of the ref erence (period measurem ent ) or a gate of known duration (fr equency m eas ur em ent). Counter 1 is a program m able divide by N counter whose out put is either counted f or one period of the reference, or, gener at es the gat e pulse during which refer ence pulses ar e counted.

I/O address es ar e decoded by U705, U706, and U707. The micropr ocess or controls t he lock- in functions t hr ough I/O ports U714-U721. U713 generates an int er r upt to the CPU every 4 msec to keep the micr opr ocess or executing in real time.

Expand

Amplifier 3/4 U511 is the X10 expand amplifier. U516 selects the display and output , eit her the output of U511 or one of the DAC outputs. Overload is detected by 1/4 and 2/4 U515 and the signal monitor is driven by 3/ 4 U515.

Front Panel

There are 62 led's on the fr ont panel contr olled by 8 serial-in, parallel-out shif t r egist er s. All 8 shift registers ar e written t o simultaneously and 8 consecutive write oper at ions ar e r equired to set the LED's. The liquid cryst al displays are managed by the display cont r ollers, U601 and U602. Exclusive-or gat es U605 and U606 drive the left over segment s. Octal latch U604 provides the logic bits for these extra segm ent s as well as the keyboard r ow strobes. U603 reads the switch closures as the r ows ar e scanned.

RS232 Interface

The RS232 interface uses an 8251A UART, U801, to send and receive byt es in a bit serial fashion. Any standard baud r at e from 300 to 19.2K baud may be selected with t he configurat ion switches. The X16 transm it and receive clock comes f r om counter 2 of U704. The RS232 interf ac e is configured as DCE so that a ter m inal may be connected with a st andar d cable. When a data byte is received by t he UART, the RxRDY output interrupt s the CPU to prevent the data from being overwritten.

GPIB Interface

The interfac e t o the GPIB is provided by U802, an MC68488 General Purpose I nterface Adapter (GPI A). The GPIB data and control lines are buffer ed by drivers U808 and U811. Because t he GPIA uses a 1 MHz clock, wait st ates are provided by U805 to synchronize I /O trans act ions with t he 4 MHz CPU. The GPIA interrupts the CPU

whenever a GPIB t r ansaction occurs which requires the CPU’s response. ( The G PIB address is set by switch bank SW1. )

Power Supplies

The line transfor m er provides two out put s, 40VAC and 15VAC, both center -tapped. The trans f ormer has dual primaries which may be selected by the voltage selector car d in t he fuse holder. The 15VAC is rectified by diode bridge BR2 and passed to 5V regulator U909. The output of U909 powers the micr opr oces sor and its related circuitry. The 40VAC output is half-wave rectified by BR1 and regulated by U901 and U902 to provide +20V and -20V. Thes e t wo dc voltages are then r egulated again by 15V regulat or s U903U908. Each 15V regulator powers a separ at e section of t he lock- in to reduce coher ent pick up between sections. U911 and U912 provide plus and minus 7.5V and U910 generates + 5V for the analog circuits.

Internal Oscillator

The internal oscillator is on a sm all circuit boar d attached to the rear panel of the instrum ent. Local regulators, Q1 and Q2, provide power t o the board. The VCO input is int er nally pulled up by R12. This pulls the VCO input to 10V when the VCO input is left open. 2/4 U1 translates the VCO input voltage to pr ovide a negat ive cont r ol voltage to U2, the funct ion generator. P3 adjusts the VCO calibration. U2 is a sine wave generator whose frequency r ange is select ed by the VCO Range switch and capacitors, C4-C6. P2 adjusts the sine wave symmet r y at low frequencies. 4/4 U1 buffer s the output of U2. P1 adjusts the amplitude of the output sine wave. The output amplitude on t he SIne Out is selected by t he amplitude switch. The output impedanc e is 600Ω.

Calibration and Repair

This section details calibration of the instrum ent. Calibration should only be done by a qualified electronics tec hnician.

Now set the both time const ants to 1S. Adjust P404 at location F4 to zer o the out put. This adjustment has a r ange of 20% of full scale on the HIGH dynamic res er ve sett ing. ( 2% on NORM and

0.2% on LO W). This zeroes t he DC output of the unit on all dynamic reserve r anges.

********** WARNING **********

The calibration procedure r equir es adjust ing the instrument with power applied and so there is a risk of per sonal injury or deat h by electric shock . Please be careful.

Most of the calibration param et er s ar e determ ined by a computer aided calibration procedur e af ter burn-in at t he fact ory. Thes e calibrat ion paramet er s are quite st able and so will no t need to be adjusted. Calibration param et er s which may need field adjustment ar e detailed below.

Multiplier Adjustments

On the HIGH dynamic reserve sett ing, there c an be some ref erence f r equency feedthr ough. This

section describes how to null this unwanted output.

This adjustment r equir es an oscilloscope and a signal generator which can proved a 500Hz refer ence signal.

Allow the unit to warm up f or about 1 hour. Reset the unit by turning it off and back on while

holding the REL key down. Select voltage input A and connect a 50Ω

term inator or shorting plug to t he A input BNC connector. Connect the 500 Hz reference signal to

the ref erence input. Set the SENSITVITY to 1mV and DYN RE S to HIGH. The PRE TIME

CONSTANT should be set t o 1mS and the POST TIME CONSTANT to NONE. Connect the scope

to the OUTPUT on the front panel. Set the scope to 2V/div and 5mS/ div. Ext ernally trigger t he s cope

using the ref er ence input s ignal. After about 60 seconds, the scope display should

show a 500 Hz sine wave on a 30 Hz (500/16 Hz) square wave. Remove t he 4 s crews holding the top panel on. Slide the top panel back about half way. Using a small screwdriver, adjust P402 at location D2 to minimize the 500 Hz output. Adjust P403 at location C2 to minimize the 30 Hz out put.

Replace the top panel.

Amplifier and Filter Adjustments

This section describes how to adjust t he Comm on Mode Rejection and Line notch filter f r equencies. An oscilloscope and a signal generator which can provide an accurat e line fr equency and twice line frequency s ignal are requir ed.

Allow the unit to warm up f or about 1 hour. Reset the unit by turning it off and back on while

holding the REL key down. Remove the 4 scr ews holding down the top panel.

Slide the panel back about halfway.

CMRR

Set the r eference frequency to 100 Hz. It is convenient to use t he SYNC output of t he signal generator as the ref erence input if it is available. Connect the sine output of the signal generator t o the A input and set the input select or to A. Wi th the SENSITIVITY at 100mV, adjust the amplitude

of the input signal to 100m V (full scale). Now set the input selector to A-B and c onnect the

signal to both the A and B inputs. Set the SENSITIVITY to 20µµµµV, the DYN RES to NORM and the BANDPASS fiter IN. Connect t he scope to the SIGNAL M ONITOR output on the rear panel. Set the scope to AC coupled, 0.2V/ div, and 10mS/div. Ext er nally tr igger t he scope using the refer ence input signal.

The CMRR is adjusted by the single turn potentionmeter located at A1 under the single hole at the front of the signal shield. (The shield is the aluminum box on the left side of the main board) . Using a small screwdriver, car efully adjust the pot to minimize the 100 Hz out put on the scope. After nulling the output , set the sensitivity to 2µµµµV and null the output again.

Notch Filters

Replacing the Front-End Transistors

Set the r eference frequency to 60.0 Hz (50. 0 Hz). It is convenient t o use the SYNC output of the signal generator as t he r eferenc e input if it is available. Connect t he sine out put of the signal generator t o the A input and set the input selector to A. With th e SENSITIVITY at 100mV, adjust the

amplitude of t he input s ignal to 100 mV (full scale). Set the LINE NOTCH to IN, the SENSITIVITY to

10mV, and the DYN RES to LOW. Connect the scope to t he SIGNAL MONITOR output on the

rear panel. Set the scope to AC coupled, 0.2V/ div, 10mS/div. Tr igger t he scope exter nally using the refer ence input signal.

The LI NE NOTCH frequency and dept h ar e adjusted by the pair of 20 turn potentiometers

located under t he m iddle two holes in the signal shield (row 4 on the circuit boar d). Using a small screwdriver, c ar ef ully adjust one pot until the line output on t he scope is minimized. Then adjust t he other pot until the output is minimized. Iter ate between the t wo pots until there is no furt her improvement. Set the SENSITIVITY to 5mV, 2mV, and 1mV, repeating the adjust m ent s at each

sensitivity. Repeat this procedur e using a r ef er ence

frequency of 120.0 Hz (100.0 Hz) and the LINEX2 NOTCH filter. The LINEX2 NOTCH is adjusted by the pair of 20 turn potent iomet er s located under the back t wo holes in the signal shield (row 5 on the circuit boar d) .

Replace the top panel.

Both the voltage and c urrent front end tr ansist or s (Q101 and Q 102) are 2N6485 (IMF6485) dual JFETS. These trans istor s ar e selected at the factory to meet the noise specifications.

This section outlines their r eplacem ent pr ocedur e in the event t hat they become damaged during use.

1) Remove the AC power cor d f r om the unit.

2) Remove top and bottom panels.

3) Release the signal shields by rem oving t he four scr ews which hold it onto the circuit board. Be car eful not to lose the nuts. Carefully slide the s hields back and then lift them out.

4) The input tr ans ist or s ar e located on the main board, just behind the input select or switch. Q101 is the voltage ( A, A-B) front end, and Q102 is the current (I) front end. Desolder and replace the appropr iat e transist or .

5) Replace the signal shields. Be car ef ul t o check that the shields do not touc h any circuit board tr aces ar ound their edges.

6) Replace the top and bot t om panels.

7) If Q101, the voltage front end has just been replaced, t he Comm on M ode Rejection needs to be readjust ed using the pr oc edur e described in the Amplifier Adjustm ent s section.

Appendix A: Noise Sources and Cures

And Other s. Other noise sources include flicker

noise found in vacuum tubes , and gener ation and recombination noise found in sem iconduct or s.

Noise, random and uncor r elat ed f luct uat ions of electronic signals, f inds its way into exper im ent s in a variety of ways. Good laborator y practice can reduce noise sources t o a manageable level, and the lock-in technique can be used to recover signals which may st ill be b uried in nois e . Intrinsic Noise Sources

Johnson Noise. Arising from f luct uat ions of electron density in a r esist or at finite temper at ure, these fluct uat ions give r ise to a mean square noise voltage,

_ V2 = ∫4kT Re[Z(f)] df = 4kTR ∆f

where k=Boltzman' s c onst ant , 1. 38x10-23J/°K; T is the absolute tem per atur e in Kelvin; the r eal part of the impedanc e, Re[z(f )] is the resistanc e R; and we are looking at the noise source with a det ector , or ac voltm eter, with a bandwidth of ∆f in Hz . Fo r

a 1MΩ resistor,

1/2

(V2)

= 0.13 µV/√Hz

All of these noise sources ar e incoher ent . Thus, the tot al noise is the square root of the sum of the squares of all the incoher ent noise sour ces.

Non-Essential Noise Sources

In addition to t he "intrinsic" noise sources listed above there ar e a variety of "non-ess ent ial" noise sources, i.e. thos e noise sour ces which can be minimized with good laborat or y pr act ice. It is worthwhile to look at what m ight be a typical noise spectrum enc ount er ed in the laborator y environment:

To obtain the rm s noise voltage that y ou would see across t his 1MΩ res is tor, we m u ltiply

0.13µV/√Hz by the s quar e r oot of the detector bandwidth. If, for example, we were looking at all frequencies bet ween dc and 1 MHz, we would expect t o see an rms Johnson noise of _

1/2

(V2)

'1/f Noise'. Arising from resist ance f luct uat ions in a current carr ying r esist or, the mean squar ed noise voltage due to '1/ f' noise is given by

_ V2 = A R2 I2 ∆f/f

where A is a dimensionless constant, 10 carbon, R is the resistance, I the current, ∆f the

bandwidth of our detect or, and f is the frequency to which the detector is tuned. For a c ar bon resistor car r ying 10 mA with R = 1k, ∆f = f = 1Hz , we have

= 0.13 µV/√Hz*(106 Hz)

= 3 µVrms

noise

1/2

= 130 µV

-11

for

Noise Spectrum

Some of t he non-essential noise sources appear in this spectrum as spikes on the intrinsic background. Ther e are several ways which these noise sources work t heir way into an exper im ent.

Capaciti ve Coupl i ng. A voltage on a nearby piece of apparat us ( or operat or) can couple t o a

detector v ia a stray capacit ance. Although C

stray may be very small, t he coupled in noise may st ill be larger than a weak exper imental signal.

Inducti ve Coupl ing. Here noise couples to the experiment v ia a magnet ic f ield:

Inductive Noise Coupling

Capacitive Noise Couplin g

To estimat e t he noise current through C

stray

into

the detector we have

i=C

stray

dV = jwC

strayVnoise

where a reasonable approximat ion t o C

stray

can be made by treating it as parallel plate capacitor.

Here, w is the radian frequency of the noise source (per haps 2 * π * 60Hz ), V

noise

is the noise voltage source am plitude ( per haps 120 VAC). For an area of A = (.01 m)2 and a distance of d =

0.1m, the 'capacitor' will have a v a lu e o f 0.009 pF and the result ing noise curr ent will b e 400pA. This meager cur r ent is about 4000 times larger than the most sens itive cur r ent scale that is available on the SR510 lock-in.

Cures for c apacitive coupling of noise signals include:

A changing current in a nearby circ uit gives r ise to a changing magnetic field which induces an em f in the loop connecting the detector to the

experiment. (emf = dØB/dt.) This is like a transf ormer , with the ex per iment-det ec t or loop as

the secondary winding.) Cures for induct ively coupled noise include:

1) rem oving or turning off t he interf er ing noise source (dif f icult t o do if the noise is a broadcast station),

2) reduce t he area of the pick-up loop by using twisted pairs or c oaxial cables, or even t wisting t he 2 coaxial cables used in differential hook-ups,

3) using magnetic shielding to prev ent t he magnetic f ield from inducing an emf (at high frequencies a simple m et al enclosure is adequate),

4) measur ing currents, not voltages, fr om high impedance experiment s.

1) rem oving or turning off t he interf er ing noise source,

2) measur ing voltages with low impedance sources and meas ur ing curr ents with high impedance sources t o r educ e the eff ect of i

stray

3) installing capacit ive shielding by placing both the experiment and the detector in a metal box.

Resisti ve Coupl i ng ( or 'Gr ound Loops' ) . Currents through common connections can give

rise to noise voltages.

Microphonics provides a path for mechanical noise to appear as electr ical noise in a circuit or

experiment. Consider the simple circuit below:

The capacitance of a coax ial cable is a function of its geomet r y so mechanical vibrations will cause the cable capacitance t o var y with time. Since C=Q/V, we have

Resistive Couplin g

Here, the detector is measuring the volt age acr os s the experiment, plus the voltage due to the noise current pass ing thr ough the f inite res istanc e of the ground bus. This pr oblem ar ises becaus e we have used two differ ent grounding points which are not at exact ly the same potential. Some cur es for gr ound loop problems include:

1) grounding everything to the same physical point,

2) using a heavier ground bus t o reduce t he potential drop along the gr ound bus,

3) rem oving sourc es of large current s from ground wires used for sm all signals.

C dV + V dC = dQ = i dt dt dt

so mechanical vibrations will cause a dC/dt which in turn gives rise to a current i, which will affect the detector . Ways to eliminate m icrophonic signals include:

1) eliminate mechanical vibrat ions,

2) tie down ex p e r imenta l c a b les s o they will no t sway to and fr o,

3) use a low noise cable that is designed to reduc e microphonic eff ects.

Thermocouple Ef f ect . The emf created by dissimilar m et al junctions can give rise t o m any

microvolts of dc potent ial, and can be a source of ac noise if the temperat ure of the junction is not held constant. This effect is large on t he scale of many low level measurement s.

Appendix B: Introd ucti on to the RS 23 2

The 'RS232' is a standard f or bit ser ial asynchronous dat a com m unicat ion. The standard defines the f ormat for data transmission, t he electrical specifications for the signal levels, and the mechanical dimensions of c onnect or s.

Despite the definition of a s t andar d, ther e are so many perm ut ations of control lines, dat a f ormat s, and transm ission speeds, t hat get t ing two RS232 devices to comm unicat e usually requires som e work.

In this sec tion, we will pr o v id e s ome basic informat ion t o aid you in connect ing your RS232 device to the SR510 Computer Interf ace.

CASE 1 - The Simplest Configuration.

the terminal responds t o a c ontrol line, it will believe that the SR510 is not r eady to accept data (because the line is not passed in t his exam ple) and will therefor e not send any dat a.

CASE 2 - RS 232 with Control Lines.

The data lines are the sam e as in Case 1. In addition to the dat a lines, there ar e two contr ol lines used:

CTS - Pin 5 "Clear to send" is a signal asserted by t he DCE to tell the DTE that t he DCE is ready to receive data.

DTR - Pin 2 0 "Data Terminal Ready" is a signal asserted by the DTE to tell the DCE that the DTE is ready to receive data.

In this case, one wire is used to send data from device A to device B and another wire is used to send data fr om device B to device A. Notice that pin 2 is an output on device A and an input on device B. (It is good practice to run the ground, pin 7, between the devices as well). The RS232 defines two types of devices; DTE (Data Ter m inal Equipment) and DCE (Data Comm unications Equipment.) An RS232 port on a comput er may be either a DTE or DCE but nearly every term inal with an RS232 port is a DTE. RS232 ports on a computer which are int ended t o connect t o a modem, such as the COM1: port on the IBM PC, are DTE. The SR530 is configured as DCE, and so it may be directly connect ed t o ASCII terminals and to the COM: port s on IBM PC's and compatibles.

As an example, consider connec t ing an RS232 ASCII comput er term inal to the SR510 using a 2 wire link. The term inal is a DTE and the SR510 is a DCE. To operate correct ly, the SR510 and the term inal must have the sam e settings for baud rate, parity, and number of stop bits. The contr ol lines in the RS232 Standard, which are used to indicate that a device is r eady t o accept dat a, must also be connected corr ectly at the term inal end. If

The SR510 responds to the c ont r ol lines as follows:

1) If the lines are not connec t ed, the SR510 assumes t hat you are ready to receive data.

2) Da t a will n o t b e transmitted fr o m the SR510 if

the DTR lin e (pin 20) is lo w. This is us e ful in th e case when your progr am is not yet ready to receive data. If data transm ission is not suspended, t hen dat a m ay be overwritt en in your computer ' s UART (as it is not being retrieved by the progr am and so will be lo s t.) When t his happens, the ' over -run' flag will be s et in your computer ' s UART and it may be recognized by the operating system , generat ing an er r or message such as "I/O Device Error " (See the "W" command in the SR510 Command List for another way to slow data transm ission. )

Baud Rate

The RS232 baud rate of t he SR510 is switch selectable from 300 t o 19.2K baud (see configurat ion switch set t ing in the front of this manual.) 19. 2K baud means that data is transm it t ed at 19,200 bits/sec ond. With one start bit, 2 stop bits, 8 data bits, and no parity bits, each ASCII charact er requires 573 µsec to be

transm it t ed (11bits/ 19. 2K baud. ) The typical data string 5. 1270< cr > has 7 character s, requiring 4 msec to be sent.

If a parity opt ion was selected, the parit y bit would be sent after the 8t h data bit, but before the first stop bit.

Stop Bits

Generally, select ion of 2 st op bits will re s u lt in fewer data trans m ission err or s. Parity

Parity

The Parity bit pr ovides a check against f ault y data transf er. It is not commonly used in local data transm ission environm ent s. If the parit y option is selected, t he SR510 will t ransm it 8 data b its and a parity bit, however , no parity check of incoming data is done.

Voltage Levels

The RS232 uses bipolar voltage levels:

Final Tip

When you are trying to get the RS232 to work with your comput er, it is helpful t o be able to 'eavesdrop' on the RS232 data lines going between the SR510 and the com put er. This can be done with an ASCII RS232 terminal and the following connector :

To test the connect or, place t he hook c lip on pin 2 of the same connect or (shor t ing pin 2 to pin 3.) Now, when you type at the terminal keyboard, data tr ansm itted from pin 2 is received at pin 3 and displayed on the t erminal screen. To use as a debugging tool, att ach the hook clip to either pin 2 or pin 3 of the RS232 cable on the SR510 to show either data s ent fr om the Computer or the SR510. The baud rate, par it y, and stop bits of the terminal must m atch those of the SR510 and the computer. If your terminal has a mode which will display control char act er s (such as carriage ret ur ns and line feeds) it is helpful to oper at e in that mode.

The control lines use positive log ic. For ex am ple, the DCE tells the DTE that it is clear to send (CTS) by placing > +3 VDC on pin 5 of the interface. Similarly, the DTE can tell the DCE that it is n ot ready by placing -3 VDC on pin 20 (DTR) of the interface.

The data lines, pins 2 and 3, use negat ive logic. A 'zero' bit is represent ed by a positive voltage and a 'one' bit is repr esented by a negative voltage. A start bit is a positive voltage and a stop bit is a negative voltage. Dat a is transm itted with the least significant bit f ir st . The lett er 'A', which has the ASCII code 41H (0100 0001) , would appear as follows:

A variant of the 'eavesdr opping' appr oac h is diagrammed below:

With this cable arr angem ent , t he ASCII terminal can listen to the data passing in both directions. The on ly d r a wb a c k is that the terminal will display garbled data if bot h devices transm it dat a at the same time.

Appendix C: Introd uction to the GPIB

The I EEE- 488 St andar d specif ies t he volt age levels, handshake requirem ent s, timing, hardware details, pinout and connect or dim ensions f or a 16 line, bit parallel bus. Many instr um ents may be connected in series t o com m unicat e over the same cable. Because t he bits are passed in parallel, the GPI B is fas t er than the RS232.

The controller ( gener ally your com puter) coordinates dat a t r ansfer on the bus by designating all part icipating instr um ent s ( including itself) as eit her a talker or a listener. Listeners c an receive data placed on t he bus by the Talker. Devices can have the capacity t o oper ate in either mode. The addr ess of each device is set by switches in the device and must be bet ween 0 and

30.

Bus Descr iption

Byte Transfer Cont r ol Group. This consists of 3

negative logic lines that implement the GPIB handshaking. The NRFD (Not Ready For Data) line is held low by any designated listener who is not ready t o accept data. When every listener is ready, t he line goes high and the talker may release data t o the bus. After data is on the bus, the talker pulls the DAV (Data Valid) line down. At this point, each listener retrieves the data. Before and during the retrieval of the data, the listener holds the NDAC (No Data Accepted) line down. When every listener has r eceived t he data, the NDAC line goes high, allowing the t alker t o release the DAV line high. Finally, the listener pulls down the NDAC line until another t r ansf er is initiated.

Data Bus : Ther e ar e eight dat a lines which use negative logic and pass the bits of each byte in

parallel. General Interface Lines: These five lines operat e

independently of t he hands hake lines and use negative logic.

1) The EOI (End or Identif y) line is used by the

talker t o designate the end of message.

2) The SRQ (Service Request ) line is used by any

device to ask fo r service. The controller can ser ial poll each device (each device retur ns an 8 bit status byt e) to determine who needs attention. It can also do a parallel poll using the EOI and ATN lines where each device is assigned a single dat a line.

3) The ATN (Attention) line makes both talkers

and listeners accept infor m ation and passes control of the DAV line to the contr oller. This line is used by the controller to ident ify talkers and listeners thr ough t heir addr esses .

4) The REN (Remote Enable) line changes the

status of an instrum ent from local to remote.

5) The IFC (Interfac e Clear) line clears t he bus of

all data and activity. Though GPIB is a very power f ul interface, str ict

protocol mus t be observed f or it to operate successfully.

Appendix D: Program Examples

All of the program examples which follow do the same thing, only the c omputer, language, or interfac e is changed. The program s read the Channel 1 and 2 Out puts and write the result s to the comput er scr een. In addition, the X6 analog output por t is ram ped from 0 to 10V.

Program Example 1: IBM PC, Basic, via RS232

In this exam ple, the I BM PC's ASYNC port (known as CO M1: or AUX: to DOS user s ) will be u s e d to communicat e with t he SR510. Only two wires between the I BM PC's ASYNC port and the SR510 are needed (pins #2 & #3 of the RS232), but pins 5,6, 8 and 20 should be connected together on the connect or at the IBM end.

10 ′ EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT 20 ′ USING IBM PC BASICA AND THE COM1: RS232 PORT. 30 ′ 40 ′ 50 ′ ON THE REAR PANEL OF THE SR510, SET SWITCH #1 OF SW2 DOWN 60 ′ AND ALL OTHER SWITCHES IN SW2 UP. (9600 BAUD, NO PARITY) 70 ′ 80 OPEN ″COM1:9600,N,8,2,CS,DS,CD″ AS #1 90 ′ SET UP COM1: PORT TO 9600 BAUD, NO PARITY, 8 DATA BITS, 2 STOP BITS, 100 ′ IGNORE CTS (CLEAR TO SEND), DSR (DATA SET READY), 110 ′ AND CD (CARRIER DETECT). 120 ′ 130 PRINT #1, ″ ″′CLEAR UART BY SENDING SPACES 140 PRINT #1,″Z″′RESET SR510 150 FOR I = 1 TO 200: NEXT I ′WAIT FOR RESET TO FINISH 160 ′ 170 X = 0 ′INIT X6 OUTPUT TO ZERO 180 ′ 190 PRINT #1, ″Q″′READ OUTPUT 200 INPUT #1,V1 ′INTO V1 210 ′ 220 PRINT ″OUTPUT = ″;V1 230 ′ 240 X =X + .0025 ′INCREMENT X6 OUTPUT BY 2.5 MV 250 IF X > 10 THEN X = 0 ′RESET X6 RAMP 260 PRINT #1, USING ″X6, ##.###″;X ′SET X6 OUTPUT VOLTAGE 270 ′ 280 GOTO 190 ′LOOP FOREVER

Program Example 2: IBM PC, Microsoft Fortran v3.3, via RS232

Machine language routines to int er f ac e t o the COM1: RS232 port are provided in the file RS232.OBJ found on t he SR575 disk. These routines allow for simple inter f acing t o t he SR510 at 19.2 kbaud from FO RTRAN programs.

$storage:2 $include: ′for232.inc′ [ for 232.inc must be included to call subroutines in RS232.OBJ [ link with RS232.OBJ (on SR565 disk) [ RS232.OBJ defines: [ init [ initializes COM1: to 19.2 kbaud [ txstr (str) str is a string terminated with ′$′ [ transmits str to COM1: [ rxstr (str) str must be declared with length of 15 or greater [ fills str with string received from COM1: [ if and error occurs, nocom is called. [ Nocom should be a FORTRAN subroutine in your program.

To use these routines, the file 'for232. inc' ( also on the SR575 disk) must be 'included' in the FORTRAN source.

Only two wires between t he IBM PC's ASYNC port and t he SR530 are needed (pins #2 & #3 of the RS232), but pins 5, 6,8 and 20 should be connected t oget her on the connect or at the IBM end.

program test

character *20 str1,str2

[ Example program to read the SR510 outputs and ramp the [ X6 analog output using Microsoft FORTRAN v3.3 and the [ COM1: port. Set all switches in SW2 to UP on SR510 [ for 19.2 kbaud.

[ initialize COM1: port to 19.2 kbaud

call init

[ set character wait interval to zero

call txstr(′w0$′)

[ reset X6 to zero

x6=0.0

[ read output into string variable str1 20 call txstr(′q$′)

call rxstr(str1)

[ convert string variable into real variable v1

read (str1,1000) v1

1000 format (bn,f10.0)

[ print results to screen

write(*,2000) v1

2000 format(′ Output 1=′,G10.3)

[ ramp x6 by 2.5 mV

x6 = x6 + .0025 if (x6.gt.10) x6 = 0.0

[ make x6 command string

write (str2,3000) x6

3000 format (′x6,′,f7.3,′$′)

call txstr(str2)

[ and loop forever

goto 20

stop end

[ ***********************************

subroutine nocom

[ in case of a timeout error, this routine runs [ put your error handler here.

[ write(*,*) char (7)

write(*,*)′RS232 Tiemout Error!′

stop end

Program Example 3: IBM PC, Microsoft C v3.0, via RS232

Machine language routines to int er f ac e t o the COM1: RS232 port are prov ided in the file RS232.OBJ found on t he SR565 disk. These routines allow for simple inter f acing t o t he SR510 at 19.2 kbaud from C programs.

#include <stdio.h>

/* Compile with >MSC program name/AL;

link with RS232.OBJ (on SR565 disk)

RS232.OBJ defines: init ()

Initializes COM1: to 19.2 kbaud

txstr (str);

Char *str; str must terminate with ′$′ char

Sends string str to COM1:

rxstr (str); str must be declared with 15 characters

or more length. Fills str with string received from COM1:

To use these routines, the large model must be used. Compile with the /AL switch and link with RS232.OBJ.

Only two wires between t he I BM PC's ASYNC por t and the SR530 are needed (pins #2 & #3 of the RS232), but pins 5, 6, 8 and 20 should be connected t oget her on the connect or at the IBM end.

main ()

If an error occurs, your procedure nocom() is called. Nocom() must be a C procedure in your program.

Example program to read the SR510 outputs and ramp the x6 analog Output using Microsoft C v3.0 (large model) and the COM1: port. Set all switches in SW2 to UP on SR510 for 19.2 kbaud.

{ char str1[20], str2[20]; float v1,x;

init (); /* init COM1: port to 19.2 kbaud */ txstr (″w0$″); /* set character interval to 0 */

x = 0; while (1)

{ txstr (″q$″); /* read channel 1 output */ rxstr (str1); /* into str1 */ sscanf (str1, ″%f″, &v1); /* scan str1 for a float variable */

x += 0.0025; /* increment x6 output by 2.5 mV */ if (x >= 10) x = 0; sprintf (str2, ″X6,%f$″, x); /* make x6 command string */ txstr (str2); /* send x6 command */

/* print results to screen */ printf (″Output = %10.36\n″, v1); }

} /* ********************************************* */ nocom ()

/* error handling routine goes here */

{

printf(″RS232 Timeout Error\n″);

putch (7);

exit ();

}

Program Example 4: IBM PC,Microsof t Basic, via GPIB

This program r equir es t he Capital Equipment Corporation GPIB card for the IBM PC or XT. It has firmwar e in ROM to interface high level languages to the G PI B.

Subro u tine calls in M ic rosof t BASIC are done t o memor y locat ions specified by t he nam e of the subroutine. The addr ess is relative to t he segment address specified by t he DEF SEG st at em ent preceding CALL.

10 ′ EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT 20 ′ USING IBM PC BASICA AND THE CAPITAL EQUIPMENT CORP. GPIB INTERFACE CARD 30 ′ 40 ′ 50 ′ ON THE SR510 REAR PANEL, SET SWITCHES #4 AND #6 ON SW1 TO DOWN (DEVICE 60 ′ ADDRESS = 23, RS232 ECHO ON) AND SWITCH # 1 ON SW2 TO DOWN (RS232 BAUD 70 ′ RATE = 9600). ALL OTHER SWITCHES SHOULD BE UP. 80 ′ NOTE THAT THE RS232 ECHO IS FOR DEBUGGING AND DEMOSTRATION PURPOSES, 90 ′ UNDER NORMAL CONDITIONING, SWITCH # 6 OF SW1 SHOULD BE UP SINCE THE RS232 100 ′ ECHO SLOWS DOWN THE GPIB INTERFACE. 110 ′ 120 DEF SEG = &HC000 ′BASE ADDRESS OF CEC CARD 130 INIT=0: TRANSMIT=3: RECV=6: ′ADDRESSES OF CEC FIRM WARE ROUTINES 140 ADDR%=21: SYS%=0 ′CONTROLLER ADDRESS 150 INZ$ = ″IFC UNT UNL MTA LISTEN 23 DATA ′Z′ 13″ 160 ′ 170 Q$ = ″IFC MTA LISTEN 23 DATA ′Q′ 13″ 180 X6$ = ″IFC MTA LISTEN 23 DATA ′X6,″ 190 LISN$ = ″IFC UNT UNL MLA TALK 23″ 200 ′ 210 ′ 220 CALL INIT(ADDR%,SYS%) ′INIT X6 OUTPUT TO ZERO 230 CALL TRANSMIT(INZ$,STATUS%) ′RESET SR510 240 GOSUB 540 ′CHECK TRANSMIT STATUS 250 ′ 260 X = 0 ′INIT X6 OUTPUT TO ZERO 270 ′ 280 CALL TRANSMIT(Q$,STATUS%) ′READ OUTPUT 290 GOSUB 540 300 GOSUB 450 ′GET RESULT 310 V1 = VAL(ANS$) ′INTO V1 320 ′ 330 ′ 340 PRINT ″OUTPUT = ″;V1 350 ′ 360 X = X + .0025 ′INCREMENT X6 OUTPUT BY 2.5 MV 370 IF X>10 THEN X 0 ′RESET RAMP 380 X$ = X6$ + STR$(X) + ″′ 13″′MAKE X6 COMMAND STRING

In this program, the CEC card's ROM starts at OC0000H, the syst em controller's addr ess is 21, and the SR530 has been assigned as GPIB address 23.

To monitor the GPIB activity with an RS232 term inal, SW1- 6 should be down, and t he ASCII term inal should be attac hed t o the rear panel RS232 connector.

390 CALL TRANSMIT (X$,STATUS%) ′SET NEW X6 VOLTAGE 400 GOSUB 540 410 ′ 420 GOTO 280 ′LOOP FOREVER 430 ′ 440 ′ GET AN ANSWER STRING FROM THE SR510 450 CALL TRANSMIT(LISN$,STATUS%) ′MAKE SR510 A TALKER 460 GOSUB 540 470 ANS$=SPACE$(10) ′INIT ANSWER STRING 480 CALL RECV(ANS$,LENGTH%STATUS%) ′READ RESULT INTO ANS$ 490 GOSUB 540 500 RETURN 510 ′ 520 ′ 530 ′ CHECK STATUS OF LAST TRANSMISSION FOR ERRORS 540 IF STATUS%=0 THEN RETURN ′STATUS OKAY 550 PRINT ″STATUS CODE = ″;STATUS%;″ ON GPIB: ERROR″ 560 STOP

Program Example 5: HP85 via GPIB

This program pr ov ides an example of an HP85 program using the GPIB inter face which could be used to cont r ol the lockin amplifier. I n this example, t he SR510 should be addressed as device #16 by setting t he switch bank SW1 per the instruct ions Page 7.

10 x=0

20 OUTPUT 716 ; ″Q″

30 ENTER 716 : V1

40 DISP ″OUTPUT = ″ : V1

50 X = X + .0025

60 IF X>10 THEN X+0

70 OUTPUT 716 : ″X6,″:X

80 GOTO 20

Documentation

This section contains t he par t s lists and schematics f or the SR510 lock-in amplifier .

The first digit of any part number can be used to locate t he scematic diagram for the part. For example, R415 is located on sheet 4 of the schematic diagrams.

SR510 PARTS LIST

Main Assembly PCB Parts Li st

NO REF. SRS par t # VALUE DESCRIPTION

1. BR1 3-00062-340 KBP201G/BR-81 D I nt egr at ed Circuit ( Thru-hole Pkg)

2. BR2 3-00062-340 KBP201G/BR-81 D I nt egr at ed Circuit ( Thru-hole Pkg)

3. BT1 6-00001-612 BR-2/ 3A 2PIN PC Bat t er y

4. C 101 5-00069- 513 .1U Capacitor, Mylar/ Poly, 50V, 5%, Rad

5. C 102 5-00069- 513 .1U Capacitor, Mylar/ Poly, 50V, 5%, Rad

6. C 103 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

7. C 104 5-00008- 501 22P Capacitor , Cer am ic Disc, 50V, 10% , SL

8. C 105 5-00002- 501 100P Capacitor, Ceram ic Disc, 50V, 10% , SL

9. C 106 5-00008- 501 22P Capacitor , Cer am ic Disc, 50V, 10% , SL

10. C 107 5-00030- 520 2200U Capacitor, Elect r olyt ic, 16V, 20% , Rad

11. C 108 5-00030- 520 2200U Capacitor, Elect r olyt ic, 16V, 20% , Rad

12. C 110 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

13. C 111 5-00081- 516 1P Capacitor, Silver Mica, 500V, 5% , DM15

14. C 116 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

15. C 117 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

16. C 118 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

17. C 120 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

18. C 121 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

19. C 122 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

20. C 123 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

21. C 124 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

22. C 125 5-00030- 520 2200U Capacitor, Elect r olyt ic, 16V, 20% , Rad

23. C 126 5-00030- 520 2200U Capacitor, Elect r olyt ic, 16V, 20% , Rad

24. C 127 5-00057- 512 .22U Cap, Stac ked M et al Film 50V 5% -40/+85c

25. C 128 5-00057- 512 .22U Cap, Stac ked M et al Film 50V 5% -40/+85c

26. C 129 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

27. C 131 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

28. C 132 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

29. C 133 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

30. C 134 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

31. C 136 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

32. C 137 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

33. C 145 5-00009- 501 24P Capacitor , Cer am ic Disc, 50V, 10% , SL

34. C 146 5-00009- 501 24P Capacitor , Cer am ic Disc, 50V, 10% , SL

35. C 147 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

36. C 148 5-00017- 501 47P Capacitor , Cer am ic Disc, 50V, 10% , SL

37. C 201 5-00020- 501 7.5P Capacitor, Ceramic Disc, 50V, 10% , SL

38. C 202 5-00109- 525 150P Capacitor, Polystyr ene, 50V, 5%, Ax

39. C 203 5-00048- 566 .0015U Cap, Polyester Film 50V 5% - 40/+85c Rad

40. C 204 5-00051- 512 .015U Cap, St ack ed M et al Film 50V 5% -40/+85c

41. C 205 5-00055- 512 .15U Cap, Stac ked M et al Film 50V 5% -40/+85c

42. C 206 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

43. C 207 5-00059- 512 .47U Cap, Stac ked M et al Film 50V 5% -40/+85c

44. C 208 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

45. C 209 5-00109- 525 150P Capacitor, Polystyr ene, 50V, 5%, Ax

46. C 210 5-00048- 566 .0015U Cap, Polyester Film 50V 5% - 40/+85c Rad

47. C 211 5-00051- 512 .015U Cap, St ack ed M et al Film 50V 5% -40/+85c

48. C 212 5-00055- 512 .15U Cap, Stac ked M et al Film 50V 5% -40/+85c

49. C 213 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

50. C 214 5-00059- 512 .47U Cap, Stac ked M et al Film 50V 5% -40/+85c

51. C 215 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

52. C 216 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

53. C 217 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

54. C 218 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

55. C 230 5-00055- 512 .15U Cap, Stac ked M et al Film 50V 5% -40/+85c

56. C 301 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

57. C 302 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

58. C 303 5-00009- 501 24P Capacitor , Cer am ic Disc, 50V, 10% , SL

59. C 304 5-00110- 525 560P Capacitor, Polystyr ene, 50V, 5%, Ax

60. C 305 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

61. C 306 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

62. C 307 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

63. C 308 5-00058- 512 .33U Cap, Stac ked M et al Film 50V 5% -40/+85c

64. C 310 5-00008- 501 22P Capacitor , Cer am ic Disc, 50V, 10% , SL

65. C 311 5-00008- 501 22P Capacitor , Cer am ic Disc, 50V, 10% , SL

66. C 312 5-00017- 501 47P Capacitor , Cer am ic Disc, 50V, 10% , SL

67. C 313 5-00017- 501 47P Capacitor , Cer am ic Disc, 50V, 10% , SL

68. C 314 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

69. C 315 5-00038- 509 10U Capacitor, Electr olyt ic, 50V, 20%, Rad

70. C 317 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

71. C 318 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

72. C 319 5-00058- 512 .33U Cap, Stac ked M et al Film 50V 5% -40/+85c

73. C 320 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

74. C 321 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

75. C 322 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

76. C 323 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

77. C 324 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

78. C 325 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

79. C 326 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

80. C 327 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

81. C 328 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

82. C 329 5-00033- 520 47U Capacitor, Electr olyt ic, 16V, 20%, Rad

83. C 330 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

84. C 331 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

85. C 332 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

86. C 333 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

87. C 334 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

88. C 335 5-00016- 501 470P Capacitor, Ceram ic Disc, 50V, 10% , SL

89. C 336 5-00016- 501 470P Capacitor, Ceram ic Disc, 50V, 10% , SL

90. C 337 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

91. C 338 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

92. C 401 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

93. C 402 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

94. C 403 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

95. C 404 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

96. C 405 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

97. C 406 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

98. C 407 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

99. C 408 5-00003- 501 10P Capacitor , Cer am ic Disc, 50V, 10% , SL

100. C 409 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

101. C 410 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

102. C 411 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

103. C 412 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

104. C 413 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

105. C 414 5-00053- 512 .033U Cap, St ack ed M et al Film 50V 5% -40/+85c

106. C 415 5-00072- 513 10U Capacitor, M ylar / Poly, 50V, 5%, Rad

107. C 416 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

108. C 417 5-00060- 512 1.0U Cap, Stac ked M et al Film 50V 5% -40/+85c

109. C 418 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

110. C 419 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

111. C 420 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

112. C 421 5-00013- 501 33P Capacitor , Cer am ic Disc, 50V, 10% , SL

113. C 422 5-00013- 501 33P Capacitor , Cer am ic Disc, 50V, 10% , SL

114. C 501 5-00012- 501 330P Capacitor, Ceram ic Disc, 50V, 10% , SL

115. C 502 5-00136- 519 .01U Capacitor, Polyst yr ene, 50V, 5%, Rad

116. C 503 5-00007- 501 220P Capacitor, Ceram ic Disc, 50V, 10% , SL

117. C 504 5-00002- 501 100P Capacitor, Ceram ic Disc, 50V, 10% , SL

118. C 505 5-00008- 501 22P Capacitor , Cer am ic Disc, 50V, 10% , SL

119. C 506 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

120. C 507 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

121. C 508 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

122. C 509 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

123. C 510 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

124. C 511 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

125. C 512 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

126. C 513 5-00054- 512 .047U Cap, St ack ed M et al Film 50V 5% -40/+85c

127. C 514 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

128. C 515 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

129. C 516 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

130. C 517 5-00002- 501 100P Capacitor, Ceram ic Disc, 50V, 10% , SL

131. C 518 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

132. C 519 5-00049- 566 .001U Cap, Polyest er Film 50V 5% - 40/ + 85c Rad

133. C 520 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

134. C 521 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

135. C 523 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

136. C 525 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

137. C 526 5-00023- 529 .1U Cap, Monolythic Ceramic, 50V, 20% , Z5U

138. C 527 5-00023- 529 .1U Cap, Monolythic Ceramic, 50V, 20% , Z5U

139. C 701 5-00007- 501 220P Capacitor, Ceram ic Disc, 50V, 10% , SL

140. C 702 5-00007- 501 220P Capacitor, Ceram ic Disc, 50V, 10% , SL

141. C 703 5-00040- 509 1.0U Capacitor, Elect r olyt ic, 50V, 20% , Rad

142. C 704 5-00040- 509 1.0U Capacitor, Elect r olyt ic, 50V, 20% , Rad

143. C 705 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

144. C 706 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

145. C 707 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

146. C 708 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

147. C 709 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

148. C 710 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

149. C 711 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

150. C 712 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

151. C 713 5-00014- 501 390P Capacitor, Ceram ic Disc, 50V, 10% , SL

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

152. C 714 5-00014- 501 390P Capacitor, Ceram ic Disc, 50V, 10% , SL

153. C 801 5-00012- 501 330P Capacitor, Ceram ic Disc, 50V, 10% , SL

154. C 802 5-00012- 501 330P Capacitor, Ceram ic Disc, 50V, 10% , SL

155. C 803 5-00012- 501 330P Capacitor, Ceram ic Disc, 50V, 10% , SL

156. C 804 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

157. C 805 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

158. C 806 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

159. C 807 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

160. C 808 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

161. C 809 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

162. C 810 5-00010- 501 270P Capacitor, Ceram ic Disc, 50V, 10% , SL

163. C 901 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

164. C 902 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

165. C 903 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

166. C 904 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

167. C 905 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

168. C 906 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

169. C 907 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

170. C 908 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

171. C 909 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

172. C 910 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

173. C 911 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

174. C 912 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

175. C 913 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

176. C 914 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

177. C 915 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

178. C 916 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

179. C 917 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

180. C 918 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

181. C 919 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

182. C 920 5-00035- 521 47U Capacitor, Electr olyt ic, 25V, 20%, Rad

183. C 923 5-00192- 542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

184. C 924 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

185. C 925 5-00046- 510 2500U Capacitor, Elect r olyt ic, 50V, 20% , Ax

186. C 926 5-00046- 510 2500U Capacitor, Elect r olyt ic, 50V, 20% , Ax

187. C 927 5-00192- 542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

188. C 928 5-00192- 542 22U MIN Cap, Mini Electrolytic, 50V, 20% Radial

189. C 929 5-00034- 526 100U Capacitor, Electr olyt ic, 35V, 20%, Rad

190. C 930 5-00034- 526 100U Capacitor, Electr olyt ic, 35V, 20%, Rad

191. C 931 5-00034- 526 100U Capacitor, Electr olyt ic, 35V, 20%, Rad

192. C 932 5-00034- 526 100U Capacitor, Electr olyt ic, 35V, 20%, Rad

193. C 933 5-00103- 524 1.0U Capacitor, Tantalum, 50V, 20%, Rad

194. C 934 5-00103- 524 1.0U Capacitor, Tantalum, 50V, 20%, Rad

195. C 935 5-00036-522 6800U Cap, Electro. 25V 10% Ax, Mallory TCX

196. C 936 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

197. C 937 5-00056- 512 .1U Cap, Stacked Metal Film 50V 5% - 40/+85c

198. C 938 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

199. C 939 5-00100- 517 2.2U Capacitor, Tantalum, 35V, 20%, Rad

200. CN801 1-00014-160 9 PIN D Connector, D-Sub, Right Angle PC, Female

201. CN802 1-00016-160 RS232 25 PIN D Connector, D-Sub, Right Angle PC, Female

202. CN803 1-00238-161 G PI B SHIELDED Connector, IEEE488, Rever se, R/A, Female

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

203. CY1 6- 00010- 620 4.000 MHZ Cryst al

204. D 101 3-00004- 301 1N4148 Diode

205. D 102 3-00004- 301 1N4148 Diode

206. D 103 3-00004- 301 1N4148 Diode

207. D 104 3-00004- 301 1N4148 Diode

208. D 105 3-00004- 301 1N4148 Diode

209. D 106 3-00004- 301 1N4148 Diode

210. D 201 3-00004- 301 1N4148 Diode

211. D 202 3-00004- 301 1N4148 Diode

212. D 203 3-00004- 301 1N4148 Diode

213. D 204 3-00004- 301 1N4148 Diode

214. D 301 3-00004- 301 1N4148 Diode

215. D 302 3-00004- 301 1N4148 Diode

216. D 303 3-00004- 301 1N4148 Diode

217. D 401 3-00004- 301 1N4148 Diode

218. D 402 3-00004- 301 1N4148 Diode

219. D 403 3-00004- 301 1N4148 Diode

220. D 404 3-00004- 301 1N4148 Diode

221. D 501 3-00004- 301 1N4148 Diode

222. D 502 3-00004- 301 1N4148 Diode

223. D 701 3-00007- 301 1N747A Diode

224. D 702 3-00203- 301 1N5711 Diode

225. D 703 3-00203- 301 1N5711 Diode

226. D 704 3-00004- 301 1N4148 Diode

227. D 901 3-00003- 301 1N4007 Diode

228. D 902 3-00003- 301 1N4007 Diode

229. D 903 3-00003- 301 1N4007 Diode

230. D 904 3-00003- 301 1N4007 Diode

231. FU1 6-00004- 611 1A 3AG Fuse

232. P 101 4-00006- 440 20 Tr im Pot , Single Turn, I n-Line Leads

233. P 102 4-00012- 441 20K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

234. P 103 4-00012- 441 20K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

235. P 104 4-00013- 441 50K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

236. P 105 4-00014- 441 5K Pot , M ult i-Tur n Tr im, 3/8" Square Top Ad

237. P 401 4-00011- 441 10K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

238. P 402 4-00011- 441 10K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

239. P 403 4-00011- 441 10K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

240. P 404 4-00011- 441 10K Pot, M ult i-Turn Trim, 3/8" Square Top Ad

241. P 501 4-00002- 440 100 Trim Pot, Single Turn, In-Line Leads

242. P 502 4-00002- 440 100 Trim Pot, Single Turn, In-Line Leads

243. PC1 7- 00036- 701 SR500 Printed Circuit Board

244. Q 101 3-00016-323 2N6485 Tr ansist or , TO-71 Package

245. Q 102 3-00016-323 2N6485 Tr ansist or , TO-71 Package

246. Q 103 3-00031-325 MPSA18 Tra ns is tor, T O- 92 Pac k a ge

247. Q 201 3-00887-325 MPS2907A Transistor , TO-92 Package

248. Q 202 3-00026-325 2N5210 Tr ansist or , TO-92 Package

249. Q 502 3-00026-325 2N5210 Tr ansist or , TO-92 Package

250. Q 701 3-00026-325 2N5210 Tr ansist or , TO-92 Package

251. Q 702 3-00026-325 2N5210 Tr ansist or , TO-92 Package

252. Q 703 3-00026-325 2N5210 Tr ansist or , TO-92 Package

253. R 101 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

254. R 102 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

255. R 103 4-00030-401 10 Resist or , Car bon Film, 1/4W, 5%

256. R 104 4-00031- 401 100 Resistor, Carbon Film, 1/ 4W, 5%

257. R 105 4-00031- 401 100 Resistor, Carbon Film, 1/ 4W, 5%

258. R 108 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

259. R 109 4-00199-407 6.81K Resistor, Met al Film, 1/8W, 1%, 50PPM

260. R 110 4-00199-407 6.81K Resistor, Met al Film, 1/8W, 1%, 50PPM

261. R 111 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

262. R 112 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM 263 R 113 4-00145-407 110 Resistor, Metal Film, 1/8W, 1%, 50PPM

264. R 114 4-00145-407 110 Resistor, Metal Film, 1/8W, 1%, 50PPM

265. R 115 4-00047-401 2.2 Resistor, Car bon Film, 1/4W, 5%

266. R 116 4-00196-407 6.04K Resistor, Met al Film, 1/8W, 1%, 50PPM

267. R 117 4-00210-407 9.09K Resistor, Met al Film, 1/8W, 1%, 50PPM

268. R 118 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

269. R 119 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

270. R 120 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

271. R 121 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

272. R 122 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

273. R 126 4-00210-407 9.09K Resistor, Met al Film, 1/8W, 1%, 50PPM

274. R 127 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

275. R 128 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

276. R 130 4-00082- 401 470K Resistor , Carbon Film, 1/4W, 5%

277. R 132 4-00082- 401 470K Resistor , Carbon Film, 1/4W, 5%

278. R 133 4-00179-407 30.1K Resistor, Met al Film, 1/8W, 1%, 50PPM

279. R 134 4-00179-407 30.1K Resistor, Met al Film, 1/8W, 1%, 50PPM

280. R 135 4-00131-407 1.00M Resistor, M etal Film, 1/8W, 1%, 50PPM

281. R 138 4-00052-401 20 Resist or , Car bon Film, 1/4W, 5%

282. R 139 4-00052-401 20 Resist or , Car bon Film, 1/4W, 5%

283. R 140 4-00150-407 13.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

284. R 141 4-00174-407 280 Resistor, Metal Film, 1/8W, 1%, 50PPM

285. R 142 4-00168-407 22.6K Resistor, Met al Film, 1/8W, 1%, 50PPM

286. R 143 4-00150-407 13.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

287. R 144 4-00157-407 16.9K Resistor, Met al Film, 1/8W, 1%, 50PPM

288. R 145 4-00157-407 16.9K Resistor, Met al Film, 1/8W, 1%, 50PPM

289. R 146 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

290. R 147 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

291. R 148 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

292. R 149 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

293. R 150 4-00179-407 30.1K Resistor, Met al Film, 1/8W, 1%, 50PPM

294. R 151 4-00201-407 634 Resistor, Metal Film, 1/8W, 1%, 50PPM

295. R 152 4-00195-407 54.9K Resistor, Met al Film, 1/8W, 1%, 50PPM

296. R 153 4-00176-407 3.01K Resistor, Met al Film, 1/8W, 1%, 50PPM

297. R 154 4-00178-407 3.83K Resistor, Met al Film, 1/8W, 1%, 50PPM

298. R 155 4-00211-407 9.53K Resistor, Met al Film, 1/8W, 1%, 50PPM

299. R 156 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

300. R 157 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

301. R 158 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

302. R 159 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

303. R 160 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

304. R 161 4-00204-407 750 Resistor, Metal Film, 1/8W, 1%, 50PPM

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

305. R 162 4-00188-407 4.99K Resistor, Met al Film, 1/8W, 1%, 50PPM

306. R 163 4-00035- 401 10M Resistor, Carbon Film, 1/4W, 5%

307. R 165 4-00215-407 909 Resistor, Metal Film, 1/8W, 1%, 50PPM

308. R 166 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

309. R 167 4-00215-407 909 Resistor, Metal Film, 1/8W, 1%, 50PPM

310. R 168 4-00141-407 100 Resistor, Metal Film, 1/8W, 1%, 50PPM

311. R 169 4-00134-407 1.24K Resistor, Met al Film, 1/8W, 1%, 50PPM

312. R 170 4-00144-407 107 Resistor, Metal Film, 1/8W, 1%, 50PPM

313. R 171 4-00182-407 33.2 Resistor, Metal Film, 1/8W, 1%, 50PPM

314. R 172 4-00035- 401 10M Resistor, Carbon Film, 1/4W, 5%

315. R 173 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

316. R 174 4-00180-407 301 Resistor, Metal Film, 1/8W, 1%, 50PPM

317. R 175 4-00165-407 200 Resistor, Metal Film, 1/8W, 1%, 50PPM

318. R 176 4-00211-407 9.53K Resistor, Met al Film, 1/8W, 1%, 50PPM

319. R 177 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

320. R 178 4-00035- 401 10M Resistor, Carbon Film, 1/4W, 5%

321. R 201 4-00135-407 1.50K Resistor, Met al Film, 1/8W, 1%, 50PPM

322. R 202 4-00194-407 5.11K Resistor, Met al Film, 1/8W, 1%, 50PPM

323. R 203 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

324. R 204 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

325. R 205 4-00153-407 15.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

326. R 206 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

327. R 207 4-00135-407 1.50K Resistor, Met al Film, 1/8W, 1%, 50PPM

328. R 208 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

329. R 209 4-00150-407 13.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

330. R 210 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

331. R 211 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

332. R 212 4-00135-407 1.50K Resistor, Met al Film, 1/8W, 1%, 50PPM

333. R 213 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

334. R 214 4-00150-407 13.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

335. R 215 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

336. R 216 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

337. R 217 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

338. R 218 4-00035- 401 10M Resistor, Carbon Film, 1/4W, 5%

339. R 219 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

340. R 220 4-00177-407 3.48K Resistor, Met al Film, 1/8W, 1%, 50PPM

341. R 221 4-00039- 401 120K Resistor , Carbon Film, 1/4W, 5%

342. R 222 4-00096- 401 62K Resistor , Carbon Film, 1/4W, 5%

343. R 223 4-00039- 401 120K Resistor , Carbon Film, 1/4W, 5%

344. R 224 4-00094- 401 6.8K Resistor, Carbon Film, 1/4W, 5%

345. R 225 4-00063- 401 3.0K Resistor, Carbon Film, 1/4W, 5%

346. R 226 4-00094- 401 6.8K Resistor, Carbon Film, 1/4W, 5%

347. R 227 4-00063- 401 3.0K Resistor, Carbon Film, 1/4W, 5%

348. R 228 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

349. R 229 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

350. R 301 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

351. R 302 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

352. R 303 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

353. R 304 4-00045- 401 2.0K Resistor, Carbon Film, 1/4W, 5%

354. R 305 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

355. R 306 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

356. R 307 4-00040- 401 13K Resistor , Carbon Film, 1/4W, 5%

357. R 308 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

358. R 309 4-00073- 401 330K Resistor , Carbon Film, 1/4W, 5%

359. R 310 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

360. R 311 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

361. R 312 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

362. R 313 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

363. R 314 4-00069- 401 300K Resistor , Carbon Film, 1/4W, 5%

364. R 315 4-00099- 401 680K Resistor , Carbon Film, 1/4W, 5%

365. R 316 4-00099- 401 680K Resistor , Carbon Film, 1/4W, 5%

366. R 317 4-00093- 401 6.2K Resistor, Carbon Film, 1/4W, 5%

367. R 318 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

368. R 319 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

369. R 320 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

370. R 321 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

371. R 322 4-00170-407 249K Resistor , Metal Film, 1/8W, 1%, 50PPM

372. R 323 4-00199-407 6.81K Resistor, Met al Film, 1/8W, 1%, 50PPM

373. R 324 4-00199-407 6.81K Resistor, Met al Film, 1/8W, 1%, 50PPM

374. R 325 4-00163-407 2.80K Resistor, Met al Film, 1/8W, 1%, 50PPM

375. R 326 4-00150-407 13.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

376. R 327 4-00159-407 2.10K Resistor, Met al Film, 1/8W, 1%, 50PPM

377. R 328 4-00029- 401 1.8K Resistor, Carbon Film, 1/4W, 5%

378. R 329 4-00088- 401 51K Resistor , Carbon Film, 1/4W, 5%

379. R 330 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

380. R 332 4-00161-407 2.49K Resistor, Met al Film, 1/8W, 1%, 50PPM

381. R 333 4-00029- 401 1.8K Resistor, Carbon Film, 1/4W, 5%

382. R 334 4-00197-407 6.49K Resistor, Met al Film, 1/8W, 1%, 50PPM

383. R 335 4-00088- 401 51K Resistor , Carbon Film, 1/4W, 5%

384. R 336 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

385. R 337 4-00035- 401 10M Resistor, Carbon Film, 1/4W, 5%

386. R 338 4-00030-401 10 Resist or , Car bon Film, 1/4W, 5%

387. R 339 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

388. R 340 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

389. R 341 4-00025- 401 1.2M Resistor, Carbon Film, 1/ 4W , 5%

390. R 342 4-00073- 401 330K Resistor , Carbon Film, 1/4W, 5%

391. R 343 4-00046- 401 2.0M Resistor, Carbon Film, 1/ 4W , 5%

392. R 344 4-00069- 401 300K Resistor , Carbon Film, 1/4W, 5%

393. R 345 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

394. R 346 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

395. R 347 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

396. R 348 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

397. R 349 4-00069- 401 300K Resistor , Carbon Film, 1/4W, 5%

398. R 350 4-00093- 401 6.2K Resistor, Carbon Film, 1/4W, 5%

399. R 351 4-00138-407 10.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

400. R 352 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

401. R 353 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

402. R 354 4-00203-407 75.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

403. R 355 4-00187-407 4.53K Resistor, Met al Film, 1/8W, 1%, 50PPM

404. R 356 4-00160-407 2.26K Resistor, Met al Film, 1/8W, 1%, 50PPM

405. R 357 4-00163-407 2.80K Resistor, Met al Film, 1/8W, 1%, 50PPM

406. R 358 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

407. R 359 4-00045- 401 2.0K Resistor, Carbon Film, 1/4W, 5%

408. R 360 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

409. R 361 4-00084- 401 5.1K Resistor, Carbon Film, 1/4W, 5%

410. R 362 4-00181-407 32.4K Resistor, Met al Film, 1/8W, 1%, 50PPM

411. R 363 4-00132-407 1.10K Resistor, Met al Film, 1/8W, 1%, 50PPM

412. R 364 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

413. R 365 4-00045- 401 2.0K Resistor, Carbon Film, 1/4W, 5%

414. R 366 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

415. R 367 4-00151-407 130K Resistor , Metal Film, 1/8W, 1%, 50PPM

416. R 368 4-00156-407 16.2K Resistor, Met al Film, 1/8W, 1%, 50PPM

417. R 369 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

418. R 370 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

419. R 371 4-00030-401 10 Resist or , Car bon Film, 1/4W, 5%

420. R 372 4-00023- 401 1.1M Resistor, Carbon Film, 1/ 4W , 5%

421. R 373 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

422. R 374 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

423. R 375 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

424. R 376 4-00033- 404 100M Resistor, Carbon Com p, 1/ 4W, 5%

425. R 377 4-00187-407 4.53K Resistor, Met al Film, 1/8W, 1%, 50PPM

426. R 378 4-00045- 401 2.0K Resistor, Carbon Film, 1/4W, 5%

427. R 401 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

428. R 402 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

429. R 403 4-00085- 401 5.1M Resistor, Carbon Film, 1/ 4W , 5%

430. R 404 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

431. R 405 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

432. R 406 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

433. R 407 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

434. R 408 4-00131-407 1.00M Resistor, M etal Film, 1/8W, 1%, 50PPM

435. R 409 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

436. R 410 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

437. R 411 4-00193-407 499 Resistor, Metal Film, 1/8W, 1%, 50PPM

438. R 412 4-00217- 408 1.000K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

439. R 413 4-00203-407 75.0K Resistor, Met al Film, 1/8W, 1%, 50PPM

440. R 414 4-00080-401 47 Resist or , Car bon Film, 1/4W, 5%

441. R 415 4-00142-407 100K Resistor , Metal Film, 1/8W, 1%, 50PPM

442. R 417 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

443. R 418 4-00132-407 1.10K Resistor, Met al Film, 1/8W, 1%, 50PPM

444. R 419 4-00179-407 30.1K Resistor, Met al Film, 1/8W, 1%, 50PPM

445. R 420 4-00183-407 348K Resistor , Metal Film, 1/8W, 1%, 50PPM

446. R 421 4-00155-407 150K Resistor , Metal Film, 1/8W, 1%, 50PPM

447. R 422 4-00184-407 37.4K Resistor, Met al Film, 1/8W, 1%, 50PPM

448. R 423 4-00212-407 9.76K Resistor, Met al Film, 1/8W, 1%, 50PPM

449. R 424 4-00161-407 2.49K Resistor, Met al Film, 1/8W, 1%, 50PPM

450. R 425 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

451. R 426 4-00045- 401 2.0K Resistor, Carbon Film, 1/4W, 5%

452. R 427 4-00131-407 1.00M Resistor, M etal Film, 1/8W, 1%, 50PPM

453. R 428 4-00131-407 1.00M Resistor, M etal Film, 1/8W, 1%, 50PPM

454. R 429 4-00146-407 110K Resistor , Metal Film, 1/8W, 1%, 50PPM

455. R 430 4-00140-407 10.2K Resistor, Met al Film, 1/8W, 1%, 50PPM

456. R 431 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

457. R 432 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

458. R 433 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

459. R 501 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

460. R 502 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

461. R 503 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

462. R 504 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

463. R 505 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

464. R 506 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

465. R 507 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

466. R 508 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

467. R 509 4-00218- 408 10.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

468. R 510 4-00219- 408 20.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

469. R 511 4-00218- 408 10.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

470. R 512 4-00219- 408 20.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

471. R 513 4-00166-407 200K Resistor , Metal Film, 1/8W, 1%, 50PPM

472. R 514 4-00207-407 806K Resistor , Metal Film, 1/8W, 1%, 50PPM

473. R 515 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

474. R 516 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

475. R 518 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

476. R 519 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

477. R 520 4-00086-401 51 Resist or , Car bon Film, 1/4W, 5%

478. R 521 4-00086-401 51 Resist or , Car bon Film, 1/4W, 5%

479. R 522 4-00218- 408 10.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

480. R 523 4-00218- 408 10.00K Resistor, M et al Film, 1/8W, 0.1%, 25ppm

481. R 524 4-00078- 401 39K Resistor , Carbon Film, 1/4W, 5%

482. R 525 4-00059- 401 22K Resistor , Carbon Film, 1/4W, 5%

483. R 526 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

484. R 527 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

485. R 528 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

486. R 529 4-00057- 401 220 Resistor, Carbon Film, 1/ 4W, 5%

487. R 530 4-00210-407 9.09K Resistor, Met al Film, 1/8W, 1%, 50PPM

488. R 531 4-00130-407 1.00K Resistor, Met al Film, 1/8W, 1%, 50PPM

489. R 532 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

490. R 533 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

491. R 534 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

492. R 535 4-00057- 401 220 Resistor, Carbon Film, 1/ 4W, 5%

493. R 536 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

494. R 537 4-00057- 401 220 Resistor, Carbon Film, 1/ 4W, 5%

495. R 538 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

496. R 539 4-00057- 401 220 Resistor, Carbon Film, 1/ 4W, 5%

497. R 540 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

498. R 541 4-00057- 401 220 Resistor, Carbon Film, 1/ 4W, 5%

499. R 542 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

500. R 543 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

501. R 544 4-00042- 401 15K Resistor , Carbon Film, 1/4W, 5%

502. R 545 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

503. R 546 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

504. R 547 4-00042- 401 15K Resistor , Carbon Film, 1/4W, 5%

505. R 548 4-00054- 401 200K Resistor , Carbon Film, 1/4W, 5%

506. R 549 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

507. R 701 4-00031- 401 100 Resistor, Carbon Film, 1/ 4W, 5%

508. R 702 4-00079- 401 4.7K Resistor, Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

509. R 703 4-00027- 401 1.5K Resistor, Carbon Film, 1/4W, 5%

510. R 705 4-00021- 401 1.0K Resistor, Carbon Film, 1/4W, 5%

511. R 706 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

512. R 707 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

513. R 708 4-00069- 401 300K Resistor , Carbon Film, 1/4W, 5%

514. R 709 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

515. R 710 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

516. R 711 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

517. R 712 4-00032- 401 100K Resistor , Carbon Film, 1/4W, 5%

518. R 801 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

519. R 802 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

520. R 803 4-00065- 401 3.3K Resistor, Carbon Film, 1/4W, 5%

521. R 901 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

522. R 902 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

523. R 903 4-00060- 401 240 Resistor, Carbon Film, 1/ 4W, 5%

524. R 904 4-00024- 401 1.2K Resistor, Carbon Film, 1/4W, 5%

525. R 905 4-00024- 401 1.2K Resistor, Carbon Film, 1/4W, 5%

526. R 906 4-00060- 401 240 Resistor, Carbon Film, 1/ 4W, 5%

527. R 907 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

528. R 908 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

529. R 909 4-00053- 401 200 Resistor, Carbon Film, 1/ 4W, 5%

530. R 910 4-00063- 401 3.0K Resistor, Carbon Film, 1/4W, 5%

531. R 911 4-00063- 401 3.0K Resistor, Carbon Film, 1/4W, 5%

532. R 912 4-00053- 401 200 Resistor, Carbon Film, 1/ 4W, 5%

533. R 913 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

534. R 914 4-00107- 402 10 Resistor, Carbon Comp, 1/2W, 5%

535. RN401 4-00220-420 10KX8 Resistor Network, DI P, 1/ 4W,2%, 8 Ind

536. RN801 4-00225-425 100KX9 Resist or Networ k SI P 1/4W 2% (Comm on)

537. RN802 4-00225-425 100KX9 Resist or Networ k SI P 1/4W 2% (Comm on)

538. SO702 1-00026-150 28 PIN 600 M I L Socket, THRU-HOLE

539. SW1 2-00014-207 SPSTX8 Swit c h , DIP

540. SW2 2-00014-207 SPSTX8 Swit c h , DIP

541. SW601 2-00017-216 4PDT Switch, Rocker, PCB Mount ( LHS of 510)

542. SW602 2-00004-213 DPDT Switch, Rocker , PCB Mount (RHS of 510)

543. T 1 6-00007- 610 SR510/530 Transf or m er

544. U 101 8-00085- 860 SR513 ASSY SRS sub assemblies

545. U 102 8-00085- 860 SR513 ASSY SRS sub assemblies

546. U 103 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

547. U 104 3- 00118- 325 78L15 Transistor, TO-92 Package

548. U 105 3- 00124- 325 79L15 Transistor, TO-92 Package

549. U 106 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

550. U 107 3-00130- 340 5532A Int egr at ed Circuit ( Thr u-hole Pkg)

551. U 108 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

552. U 109 3-00088- 340 LF353 Integrated Circuit ( Thr u-hole Pkg)

553. U 110 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

554. U 111 3-00089- 340 LF357 Integrated Circuit ( Thr u-hole Pkg)

555. U 112 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

556. U 113 3-00089- 340 LF357 Integrated Circuit ( Thr u-hole Pkg)

557. U 114 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

558. U 115 3-00089- 340 LF357 Integrated Circuit ( Thr u-hole Pkg)

559. U 117 3-00088- 340 LF353 Integrated Circuit ( Thr u-hole Pkg)

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

560. U 118 3-00130- 340 5532A Int egr at ed Circuit ( Thr u-hole Pkg)

561. U 201 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

562. U 202 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

563. U 203 3-00073- 340 CD4052 Integr at ed Circuit ( Thr u-hole Pkg)

564. U 204 3-00073- 340 CD4052 Integr at ed Circuit ( Thr u-hole Pkg)

565. U 205 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

566. U 206 3-00038- 340 74HC139 I ntegrated Circuit (Thr u-hole Pkg)

567. U 207 3-00038- 340 74HC139 I ntegrated Circuit (Thr u-hole Pkg)

568. U 208 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

569. U 301 3-00088- 340 LF353 Integrated Circuit ( Thr u-hole Pkg)

570. U 303 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

571. U 304 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

572. U 305 3-00075- 340 CD4538 Integr at ed Circuit ( Thr u-hole Pkg)

573. U 306 3-00072- 340 CD4046 Integr at ed Circuit ( Thr u-hole Pkg)

574. U 307 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

575. U 308 3-00066- 340 CA3140E Integr at ed Circuit ( Thr u-hole Pkg)

576. U 309 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

577. U 310 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

578. U 311 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

579. U 312 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

580. U 313 3-00049- 340 74HC74 Integr at ed Circuit ( Thr u-hole Pkg)

581. U 314 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

582. U 315 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

583. U 316 3-00072- 340 CD4046 Integr at ed Circuit ( Thr u-hole Pkg)

584. U 317 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

585. U 318 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

586. U 319 3-00066- 340 CA3140E Integr at ed Circuit ( Thr u-hole Pkg)

587. U 320 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

588. U 321 3-00066- 340 CA3140E Integr at ed Circuit ( Thr u-hole Pkg)

589. U 322 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

590. U 323 3-00093- 340 LM13600 Integr at ed Circuit ( Thr u-hole Pkg)

591. U 324 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

592. U 325 3-00091- 340 LF412 Integrated Circuit ( Thr u-hole Pkg)

593. U 326 3-00068- 340 CD4018 Integr at ed Circuit ( Thr u-hole Pkg)

594. U 327 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

595. U 328 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

596. U 329 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

597. U 401 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

598. U 402 3-00091- 340 LF412 Integrated Circuit ( Thr u-hole Pkg)

599. U 403 3-00090- 340 LF411 Integrated Circuit ( Thr u-hole Pkg)

600. U 404 3-00106- 340 LT1007 Integr at ed Circuit ( Thr u-hole Pkg)

601. U 405 3-00074- 340 CD4066 Integr at ed Circuit ( Thr u-hole Pkg)

602. U 406 3-00057- 340 AD534 Int egr at ed Circuit ( Thr u-hole Pkg)

603. U 407 3-00090- 340 LF411 Integrated Circuit ( Thr u-hole Pkg)

604. U 408 3-00106- 340 LT1007 Integr at ed Circuit ( Thr u-hole Pkg)

605. U 409 3-00090- 340 LF411 Integrated Circuit ( Thr u-hole Pkg)

606. U 410 3-00084- 340 ICL7650 I nt egr at ed Circuit ( Thr u-hole Pkg)

607. U 411 3-00126- 335 51A05 Relay

608. U 412 3-00126- 335 51A05 Relay

609. U 413 3-00126- 335 51A05 Relay

610. U 414 3-00126- 335 51A05 Relay

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

611. U 415 3-00126- 335 51A05 Relay

612. U 416 3-00084- 340 ICL7650 I nt egr at ed Circuit ( Thr u-hole Pkg)

613. U 417 3-00126- 335 51A05 Relay

614. U 418 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

615. U 419 3-00090- 340 LF411 Integrated Circuit ( Thr u-hole Pkg)

616. U 420 3-00064- 340 CA3081 I ntegrated Circuit (Thr u-hole Pkg)

617. U 421 3-00035- 340 74C74 Int egr ated Circuit (Thru-hole Pkg)

618. U 501 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

619. U 502 3-00058- 340 AD7524 I ntegrated Circuit (Thr u-hole Pkg)

620. U 503 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

621. U 504 3-00077- 340 DG528 Integr at ed Circuit ( Thr u-hole Pkg)

622. U 505 3-00059- 340 AD7542JN Integrated Circuit ( Thr u-hole Pkg)

623. U 506 3-00058- 340 AD7524 I ntegrated Circuit (Thr u-hole Pkg)

624. U 507 3-00077- 340 DG528 Integr at ed Circuit ( Thr u-hole Pkg)

625. U 508 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

626. U 509 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

627. U 510 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

628. U 511 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

629. U 512 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

630. U 513 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

631. U 514 3-00094- 340 LM311 Int egr at ed Circuit ( Thr u-hole Pkg)

632. U 515 3-00087- 340 LF347 Integrated Circuit ( Thr u-hole Pkg)

633. U 516 3-00076- 340 DG211 Integr at ed Circuit ( Thr u-hole Pkg)

634. U 517 3-00092- 340 LH0071 Integrated Circuit (Thru-hole Pkg)

635. U 701 3-00132- 340 Z80A-CPU Integrated Circuit ( Thr u-hole Pkg)

636. U 703 3-00081- 341 2KX8-100 STATIC RAM, I.C.

637. U 704 3-00491- 340 UPD71054C I nt egr ated Circuit (Thru-hole Pkg)

638. U 705 3-00037- 340 74HC138 I ntegrated Circuit (Thr u-hole Pkg)

639. U 706 3-00037- 340 74HC138 I ntegrated Circuit (Thr u-hole Pkg)

640. U 707 3-00037- 340 74HC138 I ntegrated Circuit (Thr u-hole Pkg)

641. U 708 3-00040- 340 74HC157 I ntegrated Circuit (Thr u-hole Pkg)

642. U 709 3-00049- 340 74HC74 Integr at ed Circuit ( Thr u-hole Pkg)

643. U 710 3-00045- 340 74HC32 Integr at ed Circuit ( Thr u-hole Pkg)

644. U 711 3-00051- 340 74HCU04 I nt egr at ed Circuit ( Thr u-hole Pkg)

645. U 712 3-00047- 340 74HC4040 Integr at ed Circuit (Thru-hole Pkg)

646. U 713 3-00049- 340 74HC74 Integr at ed Circuit ( Thr u-hole Pkg)

647. U 714 3-00042- 340 74HC175 I ntegrated Circuit (Thr u-hole Pkg)

648. U 715 3-00042- 340 74HC175 I ntegrated Circuit (Thr u-hole Pkg)

649. U 716 3-00044- 340 74HC244 I ntegrated Circuit (Thr u-hole Pkg)

650. U 717 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

651. U 718 3-00039- 340 74HC14 Integr at ed Circuit ( Thr u-hole Pkg)

652. U 719 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

653. U 720 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

654. U 721 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

655. U 722 3-00045- 340 74HC32 Integr at ed Circuit ( Thr u-hole Pkg)

656. U 801 3-00493- 340 UPD71051C I nt egr ated Circuit (Thru-hole Pkg)

657. U 802 3-00111- 340 MC68488 Int egr at ed Circuit ( Thru-hole Pkg)

658. U 803 3-00044- 340 74HC244 I ntegrated Circuit (Thr u-hole Pkg)

659. U 804 3-00044- 340 74HC244 I ntegrated Circuit (Thr u-hole Pkg)

660. U 805 3-00049- 340 74HC74 Integr at ed Circuit ( Thr u-hole Pkg)

661. U 806 3-00109- 340 MC1488 I nt egr at ed Circuit ( Thr u-hole Pkg)

SR510 PARTS LIST

No REF. SRS part # VALUE DESCRIPTION

662. U 807 3-00110- 340 MC1489 I nt egr at ed Circuit ( Thr u-hole Pkg)

663. U 808 3-00078- 340 DS75160A Integrated Circuit ( Thr u-hole Pkg)

664. U 809 3- 00117- 325 78L12 Transistor, TO-92 Package

665. U 810 3- 00123- 325 79L12 Transistor, TO-92 Package

666. U 811 3-00079- 340 DS75161A Integrated Circuit ( Thr u-hole Pkg)

667. U 901 3-00095-331 LM317K Voltage Regulator, TO-3 Metal Can

668. U 902 3-00099-331 LM337K Voltage Regulator, TO-3 Metal Can

669. U 903 3-00114-329 7815 Voltage Reg., TO- 220 ( TAB) Package

670. U 904 3-00114-329 7815 Voltage Reg., TO- 220 ( TAB) Package

671. U 905 3-00114-329 7815 Voltage Reg., TO- 220 ( TAB) Package

672. U 906 3-00120-329 7915 Voltage Reg., TO- 220 ( TAB) Package

673. U 907 3-00120-329 7915 Voltage Reg., TO- 220 ( TAB) Package

674. U 908 3-00120-329 7915 Voltage Reg., TO- 220 ( TAB) Package

675. U 909 3-00113- 340 7805CK I ntegrated Circuit (Thr u-hole Pkg)

676. U 910 3- 00116- 325 78L05 Transistor, TO-92 Package

677. U 911 3-00096- 340 LM317L I ntegrated Circuit (Thr u-hole Pkg)

678. U 912 3-00100- 340 LM337L I ntegrated Circuit (Thr u-hole Pkg)

679. Z 0 0-00004- 007 SR510 Heat Sinks

680. Z 0 0-00014- 002 6J4 Power_Entry Har dware

681. Z 0 0-00016-000 TIE ANCHO R Ha rdware, Misc .

682. Z 0 0-00017-002 TRANSCOVER Power_Ent r y Har dware

683. Z 0 0-00019- 003 MI CA Insulators

684. Z 0 0-00025- 005 3/8" Lugs

685. Z 0 0-00043- 011 4-40 KEP Nut, Kep

686. Z 0 0-00048- 011 6-32 KEP Nut, Kep

687. Z 0 0-00064- 027 6-20X5/8P Scr ew, Sheet M etal

688. Z 0 0-00079- 031 4-40X3/16 M / F Standoff

689. Z 0 0-00084- 032 36154 Termination

690. Z 0 0-00089-033 4" Tie

691. Z 0 0-00095- 040 #4 FLAT Washer, Flat

692. Z 0 0-00096- 041 #4 SPLIT Washer, Split

693. Z 0 0-00114- 050 10-1/8"#18 W ire #18 UL1007 Str ipped 3/ 8x3/ 8 No Tin

694. Z 0 0-00117- 053 12" #24 Wir e #24 UL1007 Str ip 1/4x 1/ 4 Tin

695. Z 0 0-00130- 050 5-5/8" #18 Wire #18 UL1007 Stripped 3/8x3/8 No Tin

696. Z 0 0-00132- 053 6-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

697. Z 0 0-00135- 050 7-5/8" #18 Wire #18 UL1007 Stripped 3/8x3/8 No Tin

698. Z 0 0-00136- 053 8-1/2" #24 Wire #24 UL1007 Strip 1/4x1/4 Tin

699. Z 0 0-00153-057 GROM M ET2 Grommet

700. Z 0 0-00185- 021 6-32X3/8PP Screw, Panhead Phill ips

701. Z 0 0-00187- 021 4-40X1/4PP Screw, Panhead Phill ips

702. Z 0 0-00207-003 TO-5 I nsulat or s

703. Z 0 0-00222- 021 6-32X1/4PP Screw, Panhead Phill ips

704. Z 0 0-00225- 052 17" #22 BLACK Wire #22 UL1007

705. Z 0 0-00226- 052 17" #22 WHITE Wire #22 UL1007

706. Z 0 0-00227- 052 17" #22 RED Wire #22 UL1007

707. Z 0 0-00228- 052 17" #22 GREEN Wire #22 UL1007

708. Z 0 0-00231- 043 #4 SHOULDER Washer, ny lon

709. Z 0 0-00233- 000 HANDLE1 Hardware, M isc.

710. Z 0 0-00241- 021 4-40X3/16PP Screw, Panhead Phillips

711. Z 0 0-00249- 021 6-32X1-1/ 2PP Screw, Panhead Phillips

712. Z 0 0-00256- 043 #6 SHOULDER Washer, ny lon

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

713. Z 0 0-00371- 026 4-40X3/16PF Scr ew, Black, All Types

714. Z 0 0-00500- 000 554808-1 Har dware, M isc.

715. Z 0 0-00521- 048 3" #18 Wire, #18 UL1015 Str ip 3/ 8 x 3/8 No Tin

716. Z 0 0-00526- 048 10-1/2" #18 Wire, #18 UL1015 Strip 3/8 x 3/8 No Tin

717. Z 0 0-00893- 026 8-32X3/8PF Screw, Black, All Types

718. Z 0 1-00003- 120 BNC Connector , BNC

719. Z 0 1-00010- 130 20 PIN ELH Connector, M ale

720. Z 0 1-00029-150 TO-3 Socket , THRU-HOLE

721. Z 0 1-00053- 172 USA Line Cord

722. Z 0 7-00197- 720 SR510-20 Fabricat ed Par t

723. Z 0 7-00201- 720 SR500-32 Fabricat ed Par t

724. Z 0 7-00202- 720 SR500-33 Fabricat ed Par t

725. Z 0 7-00205- 720 SR510-26 Fabricat ed Par t

726. Z 0 9-00188- 917 SR510/530 SER Product Labels

727. Z 0 9-00215- 907 1/16" BLACK Shr ink Tubing

728. Z 0 9-00216- 907 1/8" BLACK Shrink Tubing

729. Z 0 9-00217- 907 3/16" BLACK Shr ink Tubing

Internal Oscillator PCB Parts List

NO REF. SRS par t # VALUE DESCRIPTION

1. C 1 5- 00023- 529 .1U Cap, M onolyt hic Ceram ic, 50V, 20% , Z5U

2. C 2 5- 00023- 529 .1U Cap, M onolyt hic Ceram ic, 50V, 20% , Z5U

3. C 3 5- 00102- 517 4.7U Capacitor, Tant alum, 35V, 20%, Rad

4. C 4 5- 00054- 512 .047U Cap, Stac ked M et al Film 50V 5% -40/+85c

5. C 5 5- 00087- 516 390P Capacitor, Silver Mica, 500V, 5% , DM15

6. C 6 5- 00102- 517 4.7U Capacitor, Tant alum, 35V, 20%, Rad

7. C 7 5- 00014- 501 390P Capacitor, Ceramic Disc, 50V, 10%, SL

8. C 8 5- 00034- 526 100U Capacitor, Electr olytic, 35V, 20% , Rad

9. C 9 5- 00100- 517 2.2U Capacitor, Tant alum, 35V, 20%, Rad

10. C 10 5-00034- 526 100U Capacitor, Electr olyt ic, 35V, 20% , Rad

11. C 11 5-00100- 517 2.2U Capacitor, Tant alum , 35V, 20%, Rad

12. P 1 4-00016-445 10K Pot, M ulti- Tur n, Side Adjust

13. P 2 4-00003-440 100K Trim Pot , Single Turn, I n-Line Leads

14. P 3 4-00016-445 10K Pot, M ulti- Tur n, Side Adjust

15. PC1 7- 00037- 701 SR501 Printed Circuit Board

16. R 1 4- 00079- 401 4.7K Resistor, Carbon Film, 1/ 4W , 5%

17. R 2 4- 00083- 401 47K Resistor , Carbon Film, 1/4W, 5%

18. R 3 4- 00202- 407 698 Resistor, M etal Film, 1/8W, 1%, 50PPM

19. R 4 4- 00189- 407 41.2K Resistor, Met al Film, 1/8W, 1%, 50PPM

20. R 5 4- 00186- 407 4.22K Resistor, Met al Film, 1/8W, 1%, 50PPM

21. R 6 4- 00190- 407 42.2K Resistor, Met al Film, 1/8W, 1%, 50PPM

22. R 7 4- 00186- 407 4.22K Resistor, Met al Film, 1/8W, 1%, 50PPM

23. R 8 4- 00202- 407 698 Resistor, M etal Film, 1/8W, 1%, 50PPM

24. R 9 4- 00078- 401 39K Resistor , Carbon Film, 1/4W, 5%

25. R 10 4-00186- 407 4.22K Resistor, Met al Film, 1/8W, 1%, 50PPM

26. R 11 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

27. R 12 4-00042- 401 15K Resistor , Carbon Film, 1/4W, 5%

28. R 13 4-00070- 401 30K Resistor , Carbon Film, 1/4W, 5%

29. R 14 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

30. R 15 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

31. R 16 4-00079- 401 4.7K Resistor, Carbon Film, 1/4W, 5%

32. R 17 4-00104- 401 82K Resistor , Carbon Film, 1/4W, 5%

33. R 18 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

34. R 19 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

35. R 20 4-00188- 407 4.99K Resistor, Met al Film, 1/8W, 1%, 50PPM

36. R 21 4-00188- 407 4.99K Resistor, Met al Film, 1/8W, 1%, 50PPM

37. R 22 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

38. R 23 4-00022- 401 1.0M Resistor, Carbon Film, 1/ 4W , 5%

39. R 24 4-00031- 401 100 Resistor, Carbon Film, 1/4W, 5%

40. R 25 4-00031- 401 100 Resistor, Carbon Film, 1/4W, 5%

41. SW1 2-00013-215 DPDT Switch, Toggle R ight Angle PCB Mount

42. SW2 2-00013-215 DPDT Switch, Toggle R ight Angle PCB Mount

43. U 1 3- 00087- 340 LF347 I ntegrated Circuit (Thr u-hole Pkg)

44. U 2 3- 00085- 340 ICL8038 Int egr ated Circuit (Thru-hole Pkg)

45. U 3 3- 00118- 325 78L15 Transistor , TO-92 Package

46. U 4 3- 00124- 325 79L15 Transistor , TO-92 Package

47. Z 0 0-00100- 040 1/4X1/16 Was her , Flat

48. Z 0 0-00122- 053 2-1/4" #24 Wire #24 UL1007 Strip 1/ 4x1/4 Tin

49. Z 0 0-00136- 053 8-1/2" #24 Wire #24 UL1007 Strip 1/ 4x1/4 Tin

Miscellaneous Parts List

NO REF. SRS par t # VALUE DESCRIPTION

1. Z0 7-00204- 720 SR500-35 Fabricat ed Par t

2. U 702 3-00161- 342 27128-150 EPROM/PROM, I.C.

3. Z 0 0-00045- 013 4-40 MINI Nut, M ini

4. Z 0 0-00078- 031 4-40X1 M/ F Standoff

5. Z 0 0-00167- 023 6-32X1/2RP Scr ew, Roundhead Ph illips

6. Z 0 0- 00179- 000 RIGHT FOO T Har dware , M isc.

7. Z 0 0- 00180- 000 LEFT FOOT Hardware, Misc.

8. Z 0 0-00185- 021 6-32X3/8PP Screw, Panhead Phill ips

9. Z 0 0-00187- 021 4-40X1/4PP Screw, Panhead Phill ips

10. Z 0 0-00204-000 REAR FOO T Hard ware, M isc.

11. Z 0 0-00209- 021 4-40X3/8PP Screw, Panhead Phill ips

12. Z 0 0-00247- 026 6-32X1/4 TRUS SP Screw, Black, All Types

13. Z 0 0-00248- 026 10-32X3/8TRU SSP Screw, Black, All Types

14. Z 0 0-00371- 026 4-40X3/16PF Scr ew, Black, All Types

15. Z 0 6-00054- 611 .375A 3AG Fuse

16. Z 0 7-00147- 720 BAIL Fabricat ed Par t

17. Z 0 7-00198- 720 SR510-23 Fabricat ed Par t

18. Z 0 7-00199- 720 SR510-24 Fabricat ed Par t

19. Z 0 7-00200- 720 SR510-25 Fabricat ed Par t

20. Z 0 7-00203- 720 SR500-34 Fabricat ed Par t

SR510 PARTS LIST

Front Panel Parts List

NO REF. SRS par t # VALUE DESCRIPTION

1. C 601 5-00019- 501 68P Capacitor , Cer am ic Disc, 50V, 10% , SL

2. C 602 5-00019- 501 68P Capacitor , Cer am ic Disc, 50V, 10% , SL

3. C 603 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

4. C 604 5-00052- 512 .01U Cap, Stac ked M et al Film 50V 5% -40/+85c

5. C 605 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

6. C 606 5-00056-512 .1U Cap, Stacked Metal Film 50V 5% -40/+85c

7. C 607 5-00023-529 .1U Cap, Monolythic Ceramic, 50V, 20% , Z5U

8. D 601 3-00004- 301 1N4148 Diode

9. D 602 3-00004- 301 1N4148 Diode

10. D 603 3-00004- 301 1N4148 Diode

11. D 604 3-00004- 301 1N4148 Diode

12. DS601 3-00012-306 GREEN LED, Rectangular

13. DS602 3-00012-306 GREEN LED, Rectangular

14. DS603 3-00012-306 GREEN LED, Rectangular

15. DS604 3-00012-306 GREEN LED, Rectangular

16. DS605 3-00012-306 GREEN LED, Rectangular

17. DS606 3-00012-306 GREEN LED, Rectangular

18. DS607 3-00012-306 GREEN LED, Rectangular

19. DS608 3-00012-306 GREEN LED, Rectangular

20. DS609 3-00012-306 GREEN LED, Rectangular

21. DS610 3-00012-306 GREEN LED, Rectangular

22. DS611 3-00012-306 GREEN LED, Rectangular

23. DS612 3-00012-306 GREEN LED, Rectangular

24. DS613 3-00012-306 GREEN LED, Rectangular

25. DS614 3-00012-306 GREEN LED, Rectangular

26. DS615 3-00012-306 GREEN LED, Rectangular

27. DS616 3-00012-306 GREEN LED, Rectangular

28. DS617 3-00012-306 GREEN LED, Rectangular

29. DS618 3-00012-306 GREEN LED, Rectangular

30. DS619 3-00012-306 GREEN LED, Rectangular

31. DS620 3-00012-306 GREEN LED, Rectangular

32. DS621 3-00012-306 GREEN LED, Rectangular

33. DS622 3-00012-306 GREEN LED, Rectangular

34. DS623 3-00012-306 GREEN LED, Rectangular

35. DS624 3-00012-306 GREEN LED, Rectangular

36. DS625 3-00012-306 GREEN LED, Rectangular

37. DS626 3-00012-306 GREEN LED, Rectangular

38. DS627 3-00012-306 GREEN LED, Rectangular

39. DS628 3-00012-306 GREEN LED, Rectangular

40. DS629 3-00012-306 GREEN LED, Rectangular

41. DS630 3-00012-306 GREEN LED, Rectangular

42. DS631 3-00012-306 GREEN LED, Rectangular

43. DS632 3-00012-306 GREEN LED, Rectangular

44. DS633 3-00012-306 GREEN LED, Rectangular

45. DS634 3-00012-306 GREEN LED, Rectangular

46. DS635 3-00012-306 GREEN LED, Rectangular

47. DS636 3-00012-306 GREEN LED, Rectangular

48. DS637 3-00012-306 GREEN LED, Rectangular

49. DS638 3-00013-306 RED LED, Rectangular

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

50. DS639 3-00013-306 RED LED, Rectangular

51. DS640 3-00013-306 RED LED, Rectangular

52. DS641 3-00012-306 GREEN LED, Rectangular

53. DS642 3-00012-306 GREEN LED, Rectangular

54. DS643 3-00012-306 GREEN LED, Rectangular

55. DS644 3-00012-306 GREEN LED, Rectangular

56. DS645 3-00012-306 GREEN LED, Rectangular

57. DS646 3-00012-306 GREEN LED, Rectangular

58. DS647 3-00012-306 GREEN LED, Rectangular

59. DS648 3-00012-306 GREEN LED, Rectangular

60. DS649 3-00012-306 GREEN LED, Rectangular

61. DS650 3-00012-306 GREEN LED, Rectangular

62. DS651 3-00012-306 GREEN LED, Rectangular

63. DS652 3-00012-306 GREEN LED, Rectangular

64. DS653 3-00012-306 GREEN LED, Rectangular

65. DS654 3-00012-306 GREEN LED, Rectangular

66. DS655 3-00012-306 GREEN LED, Rectangular

67. DS656 3-00012-306 GREEN LED, Rectangular

68. DS657 3-00012-306 GREEN LED, Rectangular

69. DS658 3-00012-306 GREEN LED, Rectangular

70. DS659 3-00012-306 GREEN LED, Rectangular

71. DS660 3-00012-306 GREEN LED, Rectangular

72. DS661 3-00012-306 GREEN LED, Rectangular

73. DS662 3-00012-306 GREEN LED, Rectangular

74. LD1 8-00001-820 FE0206 LCD Display

75. LD2 8-00001-820 FE0206 LCD Display

76. M 1 8-00002-801 #DIV/0! Analog Met er

77. PB601 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

78. PB602 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

79. PB603 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

80. PB604 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

81. PB605 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

82. PB606 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

83. PB607 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

84. PB608 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

85. PB609 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

86. PB610 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

87. PB611 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

88. PB612 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

89. PB613 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

90. PB614 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

91. PB615 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

92. PB616 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

93. PB617 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

94. PB618 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

95. PB619 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

96. PB620 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

97. PB621 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

98. PB622 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

99. PB623 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

100. PB624 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

SR510 PARTS LIST

NO REF. SRS par t # VALUE DESCRIPTION

101. PB625 2-00001-201 D6-01-01 Switch, Moment ar y Push Button

102. PC1 7- 00038- 701 SR511 Printed Circuit Board

103. R 601 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

104. R 602 4-00034- 401 10K Resistor , Carbon Film, 1/4W, 5%

105. RN601 4-00223-425 22KX7 Resistor Network SI P 1/ 4W 2% (Comm on)

106. RN602 4-00226-425 150X9 Resistor Networ k SI P 1/ 4W 2% (Comm on)

107. RN603 4-00226-425 150X9 Resistor Networ k SI P 1/ 4W 2% (Comm on)

108. RN604 4-00221-425 150X5 Resistor Networ k SI P 1/ 4W 2% (Comm on)

109. U 601 3-00086- 340 ICM7211AM Integrated Circuit ( Thr u-hole Pkg)

110. U 602 3-00086- 340 ICM7211AM Integrated Circuit ( Thr u-hole Pkg)

111. U 603 3-00044- 340 74HC244 I ntegrated Circuit (Thr u-hole Pkg)

112. U 604 3-00046- 340 74HC374 I ntegrated Circuit (Thr u-hole Pkg)

113. U 605 3-00071- 340 CD4030 Integr at ed Circuit ( Thr u-hole Pkg)

114. U 606 3-00071- 340 CD4030 Integr at ed Circuit ( Thr u-hole Pkg)

115. U 607 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

116. U 608 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

117. U 609 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

118. U 610 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

119. U 611 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

120. U 612 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

121. U 613 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

122. U 614 3-00053- 340 74LS164 I nt egr at ed Circuit ( Thr u-hole Pkg)

123. Z 0 0-00042- 010 4-40 HEX Nut, Hex

124. Z 0 0-00077- 030 3/16"X5/16"NYL N Spacer

125. Z 0 0-00102- 042 #10 LOCK Washer, lock

126. Z 0 0-00104- 043 #4 NYLON Washer , nylon

127. Z 0 0-00106- 044 CLEAR Window

128. Z 0 0-00111- 053 1-3/4"#24B W ire #24 UL1007 Str ip 1/ 4x1/ 4 Tin

129. Z 0 0-00112- 053 1-3/4"#24R Wire #24 UL1007 Strip 1/4x 1/ 4 Tin

130. Z 0 0-00117- 053 12" #24 Wir e #24 UL1007 Str ip 1/4x 1/ 4 Tin

131. Z 0 0-00128- 053 4" #24 Wire #24 UL1007 Str ip 1/4x 1/ 4 Tin

132. Z 0 0-00129- 053 5" #24 Wire #24 UL1007 Str ip 1/4x 1/ 4 Tin

133. Z 0 0-00132- 053 6-1/2" #24 Wire #24 UL1007 Strip 1/ 4x1/4 Tin

134. Z 0 0-00139- 054 9" #26 X20 W ire #26 UL1061

135. Z 0 0-00203- 032 323914 Ter m ination

136. Z 0 1-00011- 130 20 PIN IDP Connector , Male

137. Z 0 1-00073- 120 INSL Connector, BNC

138. Z 0 1-00145- 131 20 PIN DIF POL Connector , Fem ale

139. Z 0 7-00294- 710 SR510-27 Front Panel

140. Z 0 7-00308- 709 SR510 Lexan Over lay

141. Z 0 9-00554- 913 INDIRECT, MFG MISC. EXPENSE ITEM S - QUICK FI X!

142. Z 0 9-00815- 924 DBL-SIDED 1/2" Tape, All types

Stanford Research Systems SR510 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual