Tektronix 617 Reference manual

MODEL 617

PROGRAMMABLE ELECTROMETER

QUICK REFERENCE GUIDE

INTRODUCTION

This reference and programming guide contains condensed specifica­tions, descriptions of the various features and information for using the
Model 617.

Included with descriptions of each feature are brief operating instruc­tions and some examples of typical uses.

Included with the programming information are several example pro­grams utilizing some commonh, used controllers to get the Model 617
“up and running” on the IEEE-488 bus.

0 1984, Keithlay Instruments, Inc.

Cleveland, Ohio, U.S.A.

Document Number 617903-N Rev. A

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CONTENTS

CONDENSED SPECIFICATIONS
MODEL617FEATURES
IEEE-488 PROGRAMMING
PROGRAMS.

DATA STORE OPERATION

USING HP-85
IBM PC orXT Personal Computer.
[Using Keiffiley Model 8573 Interface)
APPLE II {Using Apple Interface).

HP-s5...............-.--------~-.-*..-~---..........-

HP-9825A _........~..........._.._.........__...~.__~ _ 47

HP.9816..........-.......-....-.~......~...--.....-.~. 48

DECLSIll ............................................

PETlCBM 2001

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7
35
41

42

43

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49

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CONDENSED SPECIFICATIONS

I

INPUT IMPEDANCE: >2OOTG in parallel with 2OpF (~2pF guarded).

Range Resolution

2PJ4 O.lfA

20 PA 1 fA

200 pA 10 fA

2nA 1oofA

20 nA 1 PA

2oanA 10 pA

2fi loopA

2:: 1 10 nA nA

2mA

20mA

INPUT VOLTAGE BURDEN: <lmV except 3mV on 2OmA mnge.

VOLTS

AMPS

1 year, 18-28X

f(%rdg + counts)

Accurecy

1.6 % + 66

1.6 % + 7

1.6 % + 1

0.25% + 5

0.25% + 1

0.25% + 1

0.15% + 4

0.15% 0.15% + + 1 1

0.15% + 4

0.15% t 1

I

3

OHMS

Accuracy

Range

aokn 10 n

200Mn 10 kn

2ooGn IOMQ

MAXIMUM OPEN CIRCUIT VOLTAGE: 300VDC.

Resolution

2kn 0.1 n

20 kn 1 n

2;:

2Gn loo kn

2cGn IMn

loo n 0.25% t 1

IkQ

1 year, 18-W??. Current

f (%rdg t counts)

0.2 % t 4 1fJW

0.15% + 1 l@W

0.25% + 1 IOd

0.25% + 1 IOOIIA

0.3 % t 1 IonA

1.5 % t 1 1flA

1.5 % + 1 IllA

1.5 % + 1 lti

Test

fl.576

Ifi

VOLTAGE SOURCE

OUTFWT: - 102V to t 102V in 50mV steps.
ACCURACY: 1 year, 18+.WC; f(0.2% t 5&W)

MAXIMUM OUTPUTCURRENT: &2mA, active current limit at <4mA

with annunciation.

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GENERAL

CONVERSION TIME: 33omsec.
MAXIMUM INPUT: 25W peak, DC to 80Hz sinewave, 10s per

minute max on m4 range.
ELECTROMETER MAX COMMON-MODE VOLTAGE: 5OOV peak.
V-SOURCE MAX COMMON-MODE VOLTAGE: IOOV psak.
ENVIRONMENT:

Operating: O°C to 50°C. 70% relative humidity up to 35OC.

storage: -2FPc to t65oc.
WARMUP: 1 hour to rated accuracy.

ENGINEERING UNITS CONVERSION

PREFIX 1

femto-

pico-

nano-

micro-

milli-

kilo-

mega-

giga­tera­oeta-

5

EXPONENT

IO- ‘6
lo- ‘2
10-s
10-e
10-3
103
106
109
10’2
10’5

SAFETY PRECAUTIONS

1. Before operation, ground the instrument through a properly earth
grounded power receptacle.

2. Before servicing, disconnect the instrument from the power line, all
other equipment and consult the Model 617 instruction Manual.

3. Do not touch any terminals while the instrument is turned on or con­nected to any other test equipment.

DISPLAY ANNUNCIATORS

Readings can be displayed with either alpha exponents or numeric ax­ponents. A front panel program toggles the exponent mode (see PRO­GRAM FEATURES).

ALPHA EXPONENTS
mV or V: millivolts or volts.

kfl, MQ, Gg, M or PG: kilohms, megohms, gigohms, teraohms or
petaohms.

pA, nA, fl or mA: picoamps, nanoamps, microamps or milliamps.

nC or PC: nanocoulombs or picocoulombs.

NUMERIC EXPONENTS
Positive Exponents: 0 through 18.

Negative Exponente: -01 through - 12.
Example: A displayed exponent of - 12 = lo- 12.

Display Status-Three indicator lights define what is being read on the
display.

METER Indicator Light-Indicates that electrometer readings are be­ing displayed.

SOURCE Indicator Light-Indicates that the voltage source
W-SOURCE) value is being displayed.

DATA Indicator Light-Indicates that the data store is in the recall
mode end a previously stored reading is being displayed. A flashing
DATA light indicates that the data store is full.

NOTE:
The DISPLAY button toggles the display between source and the cur­rent mode (METER or DATA).

IEEE Status Indicators-The TALK, LISTEN and REMOTE indicators

are used when programming the instrument over the IEEE-488 bus.

These status lights are not operational during front panel instrument

operation.

DISPLAY MESSAGES

The following massages will be displayed to flag errors or conditions as
they occur:

MESSAGE

OL
r.r.

n Err

b Err

t EN

. .

IEEE “address” Program message; in IEEE ad-

dlSP Program message; in display

CAL

31inking AMPS light
3linking ZERO CHECK light In V/I zero check.

DESCRIPTION
Overrange input applied.
Displayed briefly on power up;

RAM test passed. Displayed con­stantly; RAM test failed.

Number Error. Calibration or
voltage source value exceeds
limits.

Bus Error. Instrument pro­grammed while not in remote or

an illegal command (IDDC) sent or
an illegal command option
UDDCO) sent.

Trigger Overrun Error. Instrument
triggered while processing reading
from previous trigger.

flashing decimal points on expo­nent LEDs; not using stored cal
constants. Constant decimal
points; instrument in calibration
male

dress program.

mode program.
Program massage; in cal constant

program.
In V/I current overload.

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SHIK FEATURE

DESCRIPTION

Several of the front panel buttons have a secondary function. These
functions are labeled on the front panel in the same color as the shit?
button. A secondary function is selected by first pressing the SHIFT
button and then pressing the appropriate button. More information on
these secondary functions can be found in the following text.

ZERO CHECK

and ZERO CORRECT

ZERO CHECK

ZERO CORRECT

DESCRIPTION

The zero check feature provides a means for internal zero verification.
The zero correct feature, when used with zero check, corrects internal
offsets in the instrument 50 that the display raads zero. In the zero check
mode, the input impedance of the Model 617 is changed as outlined in
the following table.

INPUT IMPEDANCE WITH ZERO CHECK ENABLED

IFUNCTION I RANGE 1 IMPEDANCE IN ZERO CHECK

Volts
Reistance

Coulombs
Current

All
All kg, 2MG

20MQ, 2OOMS, 9.09MG II 47pF
All GG

All 1OMQ I 102OpF
All pA 1OMg II 25pF

All nA 9.09Mn II 47pF
AlI fi

All mA

IOMg II 2CpF
SOSkG U 112OpF

99kn II 102OpF
lOOn II 2OpF

OPERATION

Zero Verification and Correction

1. Allow the instrument to warm up for one hour after power up.

2. Turn zero check on by pressing the ZERO CHECK button. The ZERO
CHECK indicator light will turn on.

3. Select the function and range that will be used. If unsure of range,
select the lowest range.

4. If the display does not read zero, press the ZERO CORRECT button.
The ZERO CORRECT indicator light will turn on and the display will
read zero.

5. Take the instrument out of zero check by again pressing the ZERO
CHECK button. The ZERO CHECK indicator light will turn off.

8. The instrument is now zeroed and ready to make measurements.

NOTES

1. The instrument can be rezeroad at any time by turning zero correct
off (ZERO CORRECT indicator light off) and repeating steps 1
thmugh 5.

2. Correction is automatically scaled when range is changed. However,
it is recommended that zero be checked after range or function is
changed. If range or function is to be changed without rezeroing, in­itially zero correct on the lowest range of the function to be used.

3. Check zero every 24 hours, or whenever there is a > 1 OC temperature
change.

4. On power up, zero check is on.

TYPICAL USE

Zero the 2pA range to ensure accurate measurements on that range.

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MEASUREMENT MODES

VOLTS

I

OHMS

El

1 AMPS

El

DESCRIPTION

These buttons place the Model 617 in the desired electrometer measure­ment mode. The VOLTS and OHMS buttons have sacondan/functions:
external feedback and VII modes respectively. In the external feedback
mode, the internal feedback elements are electrically removed from the
circuit so that an external element can be used instead. The VII mode
utilizes the V-Source to extend the resistance measurement capabilities
of the Model 617 to lOtaD. In this mode the Model 617 automatically
calculates the resistance from the programmed voltage value and
measured current, and then displays it.

OPERATION

Volts, Ohms and Amps:

1. Turn zero check on.

2 Determine the signal to be measured.

cl

V/I

clcl

q

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3. Press the appropriate function button.

4. Select an appropriate range or autorange.

5. Zero correct the instrument if it is not reading zero.

6. Apply the signal to the triax input connector on the mar panel.

7. Turn zero check off.

Coulombs:

1. Turn zero check on.

2. Press the COUL button.

3. Select an appropriate range or autorange.

4. Zero correct the instrument if it is not reading zero.

5. Turn zero check off.

6. Turn suppress on to cancel the small amount of charge error in­troduced by turning zero check off.

7. Apply the signal to the triax input connector on the rear panel.

‘GRN

I

“SUPPLIED INPUT CABLE

Fig 1. Voltage Resistance, Current and Charge

Measurements

VII:

1. Turn zero check on.

MODEL 617

2. Select the current function and an appropriate range fautorenge
suggested).

3. Zero correct the instrument lf it is not reading zero.

4. Set the voltage source (V-Source) to an appropriate level. (See page
20 for V-Source operation).

5. Connect the resistance to be measured to the Model 617 as shown.

6. Press the V-Source OPERATE button (OPERATE light on).

7. Turn zero check off.

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8. Note the current reading on the display. If this current is to be sup
pressed. press the SUPPRESS button (SUPPRESS light on).

9. Select the V/I function by pressing the SHIFT button and then the
OHMS button. The V/I indicator light will turn on.

10. If the displayed resistance measurement is to be suppressed, press
the SUPPRESS button. Otherwise, take the resistance measure­ments, in ohms, from the display.

*NOT USED

“SUPPLIED INPUT CABLE

SOURCE VOLTAGE

RX = MEASURED CURRENT

Pig 2. V/I Measurements

NOTES

1. To exit the VII mode, press any function button.

2. Suppress can be used with V/I ohms in two different ways. If sup-

press is enabled with the instrument in the V/i ohms mode, the
displayed resistance value (not the current being measured) will be

suppressed. In this case, the instrument can be toggled between

amps and V/I ohms without cancelling the suppressed resistance
value. However, suppress will be temporarily ignored by switching to
amps, but it will be reinstated by returning to V/I ohms.

The current can be suppressed by placing the Model 617 in the amps

mode and then enabling suppress. Entering the V/I ohms mode after
suppress is enabled will not cancel the suppressed currant, and the
displayed resistance value will reflect the suppressed current (not a
suppressed resistance). Again, the instrument can be toggled bet­ween VII ohms and amps without cancelling suppress, but the sup­pressed value will be a current for both amps and VII ohms under

these conditions.

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RANGE

RANGE

I

A

AUTO

III

DESCRIPTION

The range buttons select the desired range of measurement for the
Model 617. The range may be selected manually or automatically. With
manual range selection always use the range that allows the greatest
amount of resolution.

OPERATION

AUTO
The AUTO button toggles autoranging and manual ranging. The instru­ment is in autoranging when the AUTO indicator light is on. If the light is
off, press the AUTO button once to get into the autorange mode.

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