Tektronix ISO-4 Universal Expansion Interface,Isolation Amplifier User's Manual 24894A User manual

ISO-

Keithley MetraByte Corporation

*t***

ISO- Manual

Part Number: 24094

Revision A

Last Edit: 1987

Coptright 0 1987

bv

KEITHLEY METRABYTEIASYSTIDAC

440 Myles Standish Boulevard

Taunton, Massachusetts 02780

Telephone [phone]

FAX [phone]

WARRANTY INFORMATION

All products manufactured by Keithley MetraEIyte are warranted against defective materials

and worksmanship for a period of one year from the date of delivery to the original
purchaser. Any product that is found to be defective within the warranty period will, at the
option of Keithley MetraByte. be repaired or replaced. This warranty does not apply to
products damaged by improper use.

WAKNlNG
Keithley MetraByte assumes no Uabillty for damages consequent to the
use of this product. This product is not designed with components of a

level of reliability suitable for use in life support or ctitical applicatfons.

Information furnished by Keithley MetraByte is believed to be accurate and reliable.
However, the Keithley MetraByte Corporation assumes no responsibility for the use of such
information nor for any infringements of patents or other rights of third parties that may
result from its use.

No license is granted by implication or otherwise under any patent

rights of Keithley MetraByte Corporation.

Keithley MetraByte/Asyst/DAC is also referred to here-in as Keffhky MelraByte.
Ba[ilcTM is a trademark of Dartmouth College.

IBM@

is a registered trademark of International Business Machines Corporation.

PC, XT, AT, P&i/2. and Micro Channel Architecture@ (MCA) are trademarks of
International Business Machines Corporation.

Microsoft@ is a registered trademark of Microsoft Corporation.
Turbo C@ is a registered trademark of Borland International.

**IN**

ISO- MANUAL

TABLE OF CONTENTS

CHAPTER ONE - Introduction

1.1

Summary

of ISO- Functions

CHAPTER TWO - Hardware

2.1

2.2

Typical Input Channel Configuration
power Supplies & Cables

2.3 Gain Selection

2.4

Signal & Channel Selection

2.5 Current Measurements

2.6

'2.7

Open Input Sensor Detection

Input Filtering

2.8 Input Offset considerations

2.9

Input Offset Trim

2.10 Voltage & Current References

2.11 Using Multiple ISO-4's

CHAPTER THREE - Programming

3.1 Channel Selection

3.2 Programming with the DAS-8

3.3 Thermocouples & other Transducers

CHAPTER FOUR - Calibration
CHAPTER FIVE - Specifications

2

4

10
10
11

13 .

15

1

ISO- Manual

Introduction

CHAPTER ONE

Introduct.ion

1.1 Summary of ISO- Functions:

The ISO- is a high speed, universal expansion interface and
isolation amplifier designed for use with virtually all data
acquisition systems. The ISO- consists of 4 fully isolated,

differentially measured input channels supporting 7 jumper

selectable gains of Xl, 2, 10, 50, 100, 200, and 1000 on a per

channel basis. It also has provisions for user installable
resistors to customize the gain to your specific requirements.
Provisions have been made for
measurements using J, K,

T, R, S, 8, and E type thermocouples.

thermocouple temperature

Built-in Cold Junction Compensation (UC) providing 24 mV/Deg C
resolution is standard.

Each input channel provides very high
isolation to +/- 1000 Vdc (peak, continuous). Open thermocouple
sensing, input filtering and provisions for milliAmp measurements

make the ISO- one of the most versatile, industrial quality
multiplexors available.

The ISO- also provides an isolated 1mA

current source and an isolated, fully adjustable voltage source

(+/- 6.9 Vdc) for RTD and strain gage bridge excitation.

Multiple ISO-4's may be easily cascaded to a maximum of 128 input

channels (112 thermocouples) with every channel isolated from all
others. The ISO- is a passive amplifier/active multiplexor
design that is compatible with MetraByte's EXP-16 (High Speed
Analog Input Amplifier/Multiplexer), the DAS-8, the DASCON-1, and
the STA-08 Screw Terminal Accessory Board.

All input connections to the ISO- maybe made via the screw
terminal block located on the board (wire sizes 12-22 AWG) while
interconnection to the host data acquisition system is made
through the 37 pin D male connector provided. The ISO- may be
connected directly to MetraByte's DASCON-1 or DAS-8

(an 8
channel, 12-bit ADC board). IBM PC compatible software is
provided for automatic conversion of thermocouple measurements to

temperature when used with the DAS-8.

2

ISO- Manual

Introduction

nn

I ^.^ I

ISO-

Functional Block Diagram

3

ISO- Manual

Hardware

CHAPTER TWO

Hardware Setup & Operation

2.1 Tvoical

Imut Channel Confisuration

%e illus-tration below shows a typical ISO- input channel.
The ISO- employs a Xl gain isolation amplifier preceded by a
gain

stage using a low drift operational amplifier in the
noninverting mode. Also shown is a cross reference table for
each ISO- channel, the jumpers associated with each channel and

their function.

2.2 Power Supplies 6 Cables

When used with the DAS-8, the ISO- is powered directly from
the computer's I/O bus through the Cl000 series cable. Note that
each ISO- may draw up to 400 mA (max) and that three or more

ISO-4s (daisy chained) on the same cable may require auxiliary

power (@ +5 Vdc) applied directly to additional pairs of boards

(connector pins and ribbon cables have limited current carrying

4

ISO- Manual

Hardware

capability). DAS-B/ISO-4 interconnection cables should

be

kept as

short as possible to avoid excessive voltage drop. The DAS-8
supplies +5 volts on pin 29 and power return on pin 11 of
connectors Jl and 52.

When used with a DASCON-1 the board jumper adjacent to the

74LS85 can be switched from A to B allowing the DASCON-1 to
supply +5 Vdc on pin 20

of Jl/J2.

Auxiliary power

may be

supplied to the ISO- by removing this jumper and connecting +5
Vdc to the unmarked terminal and the return to one of the ground
feed throughs. The low level ground (pins 12 through 18) must be
connected to the +5 volt return (Pin 11). This connection is
already made in the DAS-8.

Care should

be

taken to avoid ground

loops when connecting power.

The S-1600 cable allows the ISO- to be easily connected to

the DAS-16 board.

The S-1600 makes all required analog input,

digital control and power supply connections.

2.3 ISO- Gain Selection

The ISO- supports 7 standard gains of Xl, 2, 10, 50, 100,

200, and 1000 on a per channel basis.

Gain selection is made by
placing a jumper plug over the appropriate position on 55 for
channel 0, 57 for channel 1, JlO for channel 2 or Jll for channel

3. In addition to the standard gains, each channel on the ISO-4
may be configured for any other desired gain by simply inserting
a resistor at RX1 for channel 0, RX3 for channel 1, RX5 for
channel 2 or RX7 for channel 3. The value of this resistor for
the desired gain is calculated according to the formula below.

RX~ = lOOk/(GAIN - 1)

Note that the gain

maximum

full scales input range of +/-5 Vdc.

shows the gain,

the resultant full scale input range and suggests

times

the signal must not exceed the

The following table

appropriate gain settings for various thermocouples.

GAIN

Xl
x2

x10

x50

Xl00

x200
Xl000

Since gain is set on a per channel basis and CJC is

software, any of the thermocouples listed

BIPOLAR THERH0C0UPI.E

RANGE TYPE
+I- 5
+/- 2.5
+/- 500

+/- 100 mV
+/-

+/­+/-

V
V

mV

50

mV J

25

mV

5 mV

K, E
T, S, R, B

may be

done in

used on any

channel as well as mixing thermocouples with straight voltage

inputs. The gain is adjusted using potentiometer RlO for Ch 0,
R25 for Ch 1, R52 for Ch 2, and R55 for Ch 3.

5

~ISO-4 Manual

2.4 Signal and CJC Output Channel Selection

Hardware

A total of 4 address lines are used to configure 16 ISO-

channels.

.channels are distributed among four ISO-4's.

Since each ISO- contains 4 input channels, the 16

Switch Sl acts as

the 2 most significant bits of the~4-bit address. As illustrated

below

12-15. In this way, four ISO-4's can multiplex into the

output channel while "looking like"

a single ISO-

may

be set for channels O-3, 4-7, 8-11, or

a single 16 channel MUX for

same

software purposes. This allows up to 32 ISO-4's (128 channels)
to be connected to 8 analog inputs (such as MetraByte's DAS-8)

without the need for special cabling.

Jumper 54 is used to select the ISO- output channel. It

acts as the 2 least significant bits of the 4-bit address. One,of

8 output channels is selected by placing a jumper plug over the

desired output channel number. This output channel is used for

signal output to the analog board being used. Note that 4 ISO-

4's may share the

same

output channel assignment if they are part

of the O-15 configuration as set by switch Sl.

8

ooxx

OlXX 10xX

11xX

The ISO- provides all necessary hardware for Cold Junction

Compensation (CJC). This CJC circuitry produces a +24 mV/Deg C

(0.1

Deg C/bit)

signal with 0.0 Vdc at 0 Deq C.

This signal
eminates from an isobar located on the ISO- as near the signal
connections as possible.

The CJC signal may be output on any of
the output channels by placing a jumper plug over the desired CJC
output channel on J3.

Note that compensation is done in software
and therefore the CJC output channel must be an unused, distinct
channel so that it can be read without interference from any

other channel. If CJC is not used,

place the jumper in position

X.

When used with the DAS-8,

DAS-16 or DASCON-1 A/D boards the
ISO- output channel must match the A/D board input channel. I t.
is recommended the the user first become familiar with the A/D

board prior to integrating the ISO- into the

system.

See

especially~the comments on modes on selecting the A/D input
channel, performing

digital outputs.

an

A/D conversion, and controlling the

The chart below shows the relationship between

ISO- output and DAS-8 input via the specified connector pins.

6

ISO- Manual

Hardware

output
Jumper

0

1

2.5 Current Measurement

The ISO- may be configured to measure

A/D Brd
Channel

0

1

~2

3
4
5
6

7

NC

Jl/J2

Connection

37
36
35
34

33
32
31
30

NC

Pin

milliAmp

signals by
placing a shunt resistor in parallel with the desired input
channel.

insertion of the shunt on a per channel basis.
channel 0,
channel 3.

Provisions have been made on the board for easy

RX2 is used for

RX4 for channel 1, RX6 for channel 2 or RX8 for

Using these insertion points produces an isolated
current loop input which can then be measured by the analog
board.

The following formula can be used to calculate the value

of the shunt (Rs) for the corresponding full scale mA signal.

Rs= 2/Pull Scale input current

For example, if t/- 20 mA F.S., then:

Rs=2/0.020 Rs=lOO Ohms

2.6 Open Thermocouple/Input Detection

The ISO- includes biasing resistors to allow for open

thermocouple detection.

These resistors are not connected when
the ISO- is shipped but may easily be connected by inserting a
jumper atW4 for channel 0, W3 for channel 1, W2 for channel 2
and Wl for channel 3. The use of these biasing resistors will

cause an open channel (thermocouple) to saturate at -5 Vdc. This
can be detected and a flagged in software.

2.1 Filtering

Signal

resistor/capacitor (RC) combination on a per channel

input filtering may be accomplished by using a

basis.
These RC filters may be implemented using R22-Cl for channel 0,
R37-C4 for channel 1, R40-C9 for channel 2 and R67-Cl0 for
channel 3. A break point of 1.592KHz will attenuate the 25 KHz
chopping frequency of the isolation amplifier.

This break point
can be lowered by the addition of external capacitors CXl for
channel 0,
channel 3.

CX4 for channel 1, CX9 for channel 2 and CXlO for

The value of the external capacitor in microfarads

for a break point of f Hertz is given by;

c = -.OOl +

10/(6.28f)

I

UP

ISO- Manual

Hardware

A capacitance of 0.22uf, for example,

will result in a

break point of 7.2 Hz and provide 18db attenuation at 60Hs.

The external capacitors CX2 for channel 0, CX5 for channel

CX8 for channel 2 and CXll for channel 3 shunt the respective

1,

gain resistor for the channel.

This causes the gain (if greater
than 1) to initially decrease with frequency and eventually level
off at 1. There will be a low frequency break point fl causing
an initial decrease in gain and high frequency break point (at fh

= GAIN DC x fl) causing the gain to level off at 1.

Again, for

fl in Hertz and C in microfarads the capacitance necessary for a

given low frequency break point is;

C = 10 / (6.28fl)

uF

One possible use of external capacitors CX3, CX6, CX7 and
CX12 is described below ("Offset Drift"). These capacitors shunt
the input terminals and could also be used for input filtering if
an external resistor were placed in series with the input signal.

2.8 Input
The drift of the isolation amplifier is +-20uV/deg C.

Offset Drift

The
drift of the operational amplifier (OP-07D) is +-2.5uV/deg C
times the gain.

The total offset will be the sum of these two
components. At high gains the offset of the OP-07D will
dominate. Should this drift be excessive, a pin compatible

stabilized TSC911A with a drift of
substituted for OP-07D.

In this case a O.luF capacitor may be

+/-.15uV/deg C could be

necessary at CX3 for channel 0, CX6 for channel 1, CX7 for
channel 2 or CX12 for channel 3 in order to filter switching
spikes of the TSC911A.

2.9 Input Offset Trim

The offset voltages for the 4 ISO- channels can be adjusted

to 0 Vdc using potentiometers R14 for channel 0, R28 for channel

1, R49 for channel 2 andR58 for channel 3. The voltage dividers
R9-R15, R24-R30, R53-R47 and R54-R60 for channels 0 through 3
make for a fine null adjustment. By varying the voltage
dividers,

corresponding offsets from -7.5 to +7.5 Vdc can be

obtained.

2.10 ~Voltage and Current References

The ISO- provides a voltage reference between -6.9 volts
and +6.9 volts and ~a precision current source of 1 ma. The
sources are provided at the screw terminals of J13. The left
terminal sources the current and the right terminal is the

voltage reference. The center terminal is the return in both

cases.

The current source may be used for 100 ohm RTD's while

the voltage source may be used for strain gage bridge excitation.

8

ISO- Manual

2.11 Cascading Multiple ISO-4's

Hardware

Since the ISO- provides 8 jumper selectable output channels

and 4 switch selectable board decodes it is possible

to cascade
up to 32 ISC-4s for a single, 8 channel analog input board. As
mentioned before, each group of 4 ISO-4's

must

have a different,
unused output channel and each board within the group must have a
different switch decode (Base Address). This allows a
with 128 channels

of standard voltage (and/or current)

measurement or up to 112 thermocouple channels (with CJC).

system

This

cascading is particularly easy when used in conjunction with

MetraByte's DAS-8.

Each group of 4 ISO-4s should be set to a

distinct output channel corresponding to one of the A/D board's

input channels.

'.

The ISO- may also be cascaded to MetraByte's EXP-16
Universal Expansion Interface provided separate outputs are
configured for each group of 4 ISO- boards and the individual
EXP-16s.
Board

Similarly the MetraByte STA-08 Screw Terminal Accessory

may

be connected directly to an ISO- group leaving 6 or 7
single-ended inputs available on the STA-08 (depending upon CJC
implementation).

9

ISO- MANUAL Programming

CHAPTER THREE

Programming

3.1 CHANNEL SELECTION

The following section deals mainly with ISO- usage in
conjunction with MetraByte's DAS-8 and DAS-16(F) boards. ..An
example is given in BASICA as implemented on the IBM PC using

DAS-8 mode programming.

This chapter is not intended to teach

the basics of DAS-8 programming since these topics are covered in

depth in the DAS-8 manual (note especially modes l-9 and 14).
However, since the 150-4

acquisition

system,

may

be used in conjunction with

an

overview of ISO- software access is

any

data

presented.

ISO- programming is quite

straightforward using a 4-bit
address to specify 1 of 16 ISO- channels. The ISO- is a
passive amplifier/active multiplexor design meaning that the user
need merely activate the channel MUX on the ISO- in order to
receive the amplified signal. This 4-bit address may be

specified by any 4 TTL compatible output signals (the address is
not latched and must be held by the TTL signals). The 4-bit
address is mapped to pins 7-10 on connector Jl/J2 with pin 7
being the least significant
significant bit. Since

bit

many

and pin 10 being the

most

dat.a acquisition systems
automatically initiate an A/D conversion upon channel access, the
suggested ISO- programming sequence might be:

Specify the 4-bit ISO- output channel (O-15).

1)
Access the analog input channel and initiate the A/D conversion.

2)

Retrieve the digitized data.

3)

3.2 ISO- Programming with the DAS-8

ISO- channel access is chosen using a "mode 14" DAS-8 call

routine.

The "mode 14" call sets digital output

bits

OPO - OP3
which are mapped directly to the 4 ISO- address bits. Once the
"mode 14" call is executed OPO through OP3 outputs remain set.
Subsequent A/D conversions will be performed on that channel. To
read other channels the "mode 14" routine should be called again
and a new input channel selected. By using a BASIC "FOR .._

NEXT" loop the input channels of the ISO- can be scanned. The

following example shows the programming steps required
the channels of a single ISO-4,

read the A/D (using mode 4) and
store the data in an array called DIO%. Note that the DAS-8
have previously been configured

(see the DAS-8 manual for

to scan

must

details.).

10

ISO- MANUAL

Programming

XXX10

DIM DI0%(3)

'DIM DATA ARRAY FOR

'4 ENTRIES
xxx20
xxx30

MD%=l: LT%(O)=l: .LT%(l)=l
CALL DASB(MD%,LT%,FLAG%)

'SET DAS-8 CHANNEL

'To 0 ~THIS MUST

'MATcHISO-~ CHANNEL)

xxx40

FOR I=0 TO 3
xxx50 MD%=14: OP%=I
xxx60 CALL DAS8 (MD%,OP%,FLAG%)
xxx70
xxx80

MD%=4

CALL DASE(MD%,DIO%(I),FLAG%)

xxx90 NEXT I

'SCAN 4 INPUTS
'SET ISO- ADDRESS TO

'BOARD 0, LINE I

'DO CONVERSION AND

'STORE IN DIO(1)

'COMPLETE SCAN

Data from channel 0 will be in array DIO%(O), channel 1 in

DIO%(l) etc.

For single ISO- usage with a DAS-8, refer to the

program ONE-ISO.BAS on the accompanying floppy disk.

Suppose a second ISO- had been setup to respond to address

4 and output on channel 0. Further suppose DIO% had been
dimensioned for 8 in statement xxx10 and the FOR loop in xxx40

was from 0 to 7. Then data from channels 0 through 3 of the

first ISO- (address 0) would be in DIO%(O) through DI0%(3) and
data from channels 0 through 3 of the second ISO- (address 4)

would be in DI0%(4) through DI0%(7).

A more general case is

included on the accompanying floppy under the name MANY-ISO.BAS.

3.3 Thermocouples

and Other Transducers

Low level signals such as thermocouples, strain gage bridges

(load cells, pressure and force transducers), etc. require

significant amplification prior to A/D conversion on many high

level

analog boards.

The ISO- incorporates stable
amplification, cold junction compensation for thermocouples and
an isolated reference for strain gages.

The disk accompanying the DAS-8 (Rev 1.7 or latter) contains
BASIC programs illustrating ISO- usage with a DAS-8. Though
this package has been written to interface directly with the
MetraByte DAS-8, the thermocouple linearization routines can
easily be generalized to perform the linearization on any set of
thermocouple data.

The included programs are as follows:

ONE-ISO.BAS - An example using 1 ISO- with a DAS-8
MANY-ISO.BAS - An example using 3 ISO-4s with a DAS-8
ISO-J.BAS - Examples using thermocouples inputs
J.BAS thru R.BAS - Thermocouple linearization subroutines

IS04TST.BAS - A program to

assist

setting up and

calibrating the IS04.

11

ISO- MANUAL

A similar set of programs have been developed based on the
MetraByte DAS-16 and DAS-16F. These programs are included on the
DAS-16 Utility disk. The following list details the program
names and their functions

ONE-IS06.BAS - An example using 1 150-4 with a DAS-8

MANYIS06.BAS - An example using 3 ISO-4s with a DAS-8
ISO-J16.BAS - Examples using thermocouples inputs

J.BAS thru R.BAS - Thermocouple lineariiation subroutines

ISOTST16.BAS - A program to assist setting up and

calibrating the IS04.

The thermocouple subroutines are stored in ASCII format., so

they can be easily merged into your own BASIC programs.
example~has distinct line numbering so that several can be
merged and used together for different types of thermocouples.
The subroutines are commented and consist of a data section that
should be GOSUB'ed in the initialization section of your program.
These routines load a look up array (itmaytake a few seconds to

load).
interpolation. This method is both fast and accurate over the
full operating temperature range of the thermocouples.

error messages, data should be bounded to physically realizable
min/max values before entering the subroutines.

The second section of each subroutine performs a linear

Programming

Each

To avoid

The programming examples are one way (not necessarily the

best) of programming the ISO- with the DAS-16 and DAS-8 and can

serve as a starting point for user specific programs.

12

ISO- Manual

Calibration

CHAPTER POUR

Calibration

4.1 Calibration and Test

Periodic recalibration of the ISO- is recommended to retain

high accuracy.

The recalibration interval, to a large extent,

depends upon the type of service to which the board is subjected.

For an environment with large temperature changes or vibration a
3 month recalibration interval is recommended.

For laboratory or

office conditions 6 months to 1 year is generally acceptable.

Accurate calibration requires a 4 l/2 digit DMM and a
precision voltage calibrator or other stable, noise-free DC
voltage source usable with the multimeter.

In addition, if CJC

circuitry is to be calibrated a digital thermometer (or other

temperature measuring device with +/-2,degrees C accuracy) is

required.

The IS04TST.BAS program included on the DAS-8 disk (Rev 1.7
or latter) or the ISOTST16.BAS included on the DAS-16 disk may be
used for data channel and CJC circuit calibration. Both programs
are fully prompted, and the user need only follow the directions
to perform a complete board test and calibration.

4.2 Calibration Procedure

Connect +5 volt power to the ISO-4.

The simplest way to

power the ISO- is to connect it with the C-1800 cable to a DAS-

8. Otherwise connect +5 to Pin 29 of Jl or 52 and +5 return to

Pin 11 of Jlor 52. The +5 volt return must also be connected to
one of the low level grounds (Pins 12 through 18).

Set the DMM to DC Volts and wire it between the LL GND and

one

of the jumper pins on the upper.side of the output channel

jumper connector J4.

It will be necessary to activate each channel using "mode

14" DAS-8 routine or (if not using the DAS-8) supply high and low

levels to the address lines A0 Pin 7, Al Pin 8, A2 Pin 9 and A3

Pin 10 of Jl or 52. Because LS-TTL inputs float high it probably

suffices to pull the desired lines low. Configuring the ISO- to
respond as address 3 would allow A2 and A3 to be floated so that
A0 and Al could be used to address the individual channels.

13

ISO- Manual

Calibration

To ZERO each channel, short the input terminals together

(5‘5, J8,

J9 or 512) and set the channel gain to the gain that you
would normally use by placing the jumper over the appropriate
position of the gain selection jumper block (J5, J7, JlO or Jll).
Adjust the ZERO potentiometer (R14 for channel 0, R28 for channel

R49 for channel. 2 and ~58 for channel 3) for best 0 Vdc

1,

reading.

To set GAIN remove the shorts at the input terminals (56,

Jf3,

J9 or 512) and connect a +5 volt source with the positive

source terminal to 11+'

and the negative source terminal to "-".

Adjust the input voltage so that the input voltage times the gain

is equal to +5 volts.
input to 5v/lO = 0.5 volts.

For example,

Adjust the GAIN potentiometer (RlO

for channel 0, R2:5 for channel 1,

if the gain is 10 set.,the

R52 for channel 2 or R55 for

channel 3) for +S.OOO volts plus or minus 1mV on the DMM.

4.3 CJC Circuit Calibration

Connect the DMM (set to DC volts) between LL GND and one of
the jumper pins on the upper side of the output channel jumper
connector (53).

Monitor the temperature in the vicinity of the ISO- board.
For greatest accuracy the temperature should be measured close to
the ISO- temperature sensor (CRlO).

Adjust the CJC ADJ potentiometer (R84) for best reading of

24.4 mV per degree C. For example,,if room temperature is 17.0

degrees C, the CJC ADJ should be adjusted for 24.4 x 17 = .4148

volts.

4.4 Reference Calibration

To adjust the VOLTAGE reference connect the positive DMM

Iead to the right terminal and the negative lead to the center

terminal of 513.

Adjust potentiometer R74 for a DMM reading

between -6.9 and +6.9 volts.

To adjust the CURRENT reference connect a 0.1% resistor with

a value approximating the transducer resistance between the left
and center terminals of J13. Measure the voltage across the
resistor.

Adjust R73 for a voltage of 0.001 times the resistor

value (negative lead to center terminal of 513. For example with

a 100 ohm resistor the meter should read 0.1 volt.

Alternatively connect a DMM (set to milliamps) with its

positive lead to the left terminal and its negative

lead to the

center terminal of 513 and adjust R73 for best 1 mA reading.

Most DMMs are not good enough for an accurate adjustment of R73

however.

14

ISO- MANUAL

SPECIFICATIONS

Analog Data Specifications

Specifications

CHAPTER FIVE

Specifications

Input Bias Current

Safe Diff Voltage
Common Mode Voltage
CMR
Output Voltage
Maximum Output Current
Voltage Drift, RTO
Nonlinearity

Settling Time
Bandwidth

Cold Junction Compensation

Origin
Variation

References Sources

VoltageSource

Current Source

3na TYP,

14na Max over temp range
+/- 30 volts continuous
+I- 1000 volts continuous
1OOdb @ 60 Hz
+/- 5 volts
+I- 15 ma
c/-(20 + 2.5*GAIN) uVolts/deg C
t/-0.025% TYP
1 ms to +/-1Omv with 1OV step
5KHz with switching filter removed

0.0 volt at 0.0 deg C
~24.4

+/- 6.8 volt @

mv /

deg C

5ma

MAX

(user adjustable)

1.000 mA (1000 Megohm output impedance

at DC Current Source)

Compliance
Temperature Coefficient

Environmental

Operating Temp Range
Storage Temp Range
Humidity

-10 volts to +2.5 volts

+/-30 ppm / deg C

0 to 50 deg C

-20 to 70 deg C

0 to 90 % non-condensing

15

ISO- MANUAL

Power Requirements

+ 5

Physical

Specifications

Vdc @ 400 mA (max)

Dimensions
Screw Term Spacing

8"x4 75"x.75"

0.19+

(5

(no standoffs)

mm)

Screw Term Wire Size 12-22 AWG
Standoffs l/2 u

Interface Connectors Jl and 52

All computer interface

connections are made through two

parallel 37 pin D type connectors.

(12.7 mm)

In addition pins 2 through 6,

12,13,15,19 and 21 though 28 are brought out to plated through
holes on the board allowing the user access to these pins for DAS­8 clocks or interrupt usage.

PIN NAME FUNCTION

1

7
8

9

10

11

NC NO CONNECTION
AU LSB OF DIGITAL CONTROL CHAN

Al

2SB OF DIGITAL CONTROL CHAN
A2 4SB OF DIGITAL CONTROL CHAN
A3 MSB OF DIGITAL CONTROL CHAN

COM

DIGITAL COMMON (+5 VOLT RETURN)

14

16

LLG
LLG

17 LLG
18

20 +5v

LLG

29 +5v

30 OUT7
31 OUT6
32 OUT5
33 OUT4
34 OUT3
35 OUT2

OUT1
OUT0

LOW LEVEL GROUNDS

+5

VOLTS FORM PC (DASCON-1

config)

+5 VOLTS FROM PC (DAS-8 config)

ANALOG OUTPUT 7
ANALOG OUTPUT 6
ANALOG OUTPUT 5
ANALOG OUTPUT 4
ANALOG OUTPUT 3
ANALOG OUTPUT 2
ANALOG OUTPUT 1
ANALOG OUTPUT 0

16