Tektronix 1792 Instruction Manual

INSTRUCTION MAdUAL

Models 1792,6422
Isolated BCD Outputs

Keithley instruments, Inc.
28775 Aurora Road/Cleveland, Ohio 44139/(216) 248-0400

WARRANTY

Keithley Instruments, inc. warrants this product to be free from defects
in material and workmanship for a period of 1 year from date of ship­ment. During the warranty period, we will, at our option, either repair
or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithley represent­ative, or contact Keithley headquarters in Cleveland, Ohio. You will be

given prompt assistance and return instructions. Send the instrument,
transportation prepaid, to the indicated service facility. Repairs will be
made and the instrument returned, transportation prepaid. Repaired
products are warranted for the balance of the original warranty period,
or at least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from unauthorized

modification or misuse of any product or part. This warranty also does

not apply to fuses, batteries, or damage from battery leakage.

This warranty is in lieu of all other warranties, expressed or implied, in-

cluding any implied warranty of merchantability or fitness for a par­ticular use. Keithley Instruments, Inc. shall not be liable for any indirect,
special or consequential damages.

STATEMENT OF CALIBRATION

This instrument has been inspected and tested in accordance with
specifications published by Keithley Instruments, Inc.

The accuracy and calibration of this instrument are traceable to the

National Bureau of Standards through equipment which is calibrated at

planned intervals by comparison to certified standards maintained in
the Laboratories of Keithley Instruments, Inc.

KEITHLEY INSTRUMENTS, INC.
INSTRUMENT DIVISION / 28775 Aurora Road / Cleveland, Ohio 44139 / U.S.A. / [phone] / Telex: 98-5469

WEST GERMANY: Keithley Instruments GmbH / Heiglhofstr. 5 / 8000 Munchen 70 / [phone] / Telex: 52-l 2160
GREAT BRITAIN: Keithley Instruments, Ltd. I 1, Boulton Road I Reading, Berkshire RG 2 ONL / [phone]/88 /Telex: 84-7047
FRANCE: Keithley Instruments SARL / 2, Bis Rue Leon Blum / B.P. 60 / 91121 Palaiseau Cedex / (6) 011-51-55 I Telex: 600-933
NETHERLANDS: Keithley Instruments BV / Arkelsedijk 4 / Postbus 559 / 4200 AN Gorinchem I (0) 1830-25577 / Telex: 24-684
SWITZERLAND: Keithley Instruments SA I Kriesbachstr. 4 / 8600 Dubendorf I 01/821-94-44 / Telex: 57-536
AUSTRIA: Keithley Instruments Ges.m.b.H. / Doblinger Haupstr. 32 / 1190 Wien / 314 289 / Telex: 13-4500

MODELS 1792, 6422

I SOLATED BCD OUTPUTS

Copyright 1979, Keithley Instruments, Inc.

Third Printing, May 1981, Cleveland, Ohio

Document No. 30155, Rev. B

U.S.A.

TABLE OF CONTENTS

SECTION TITLE

1.
l-l.

l-3. COHPATIBILITY. ..................... l-l

l-5. WARRANTY INFORMATION .................. l-l

l-7. CHANGE NOTICES ..................... l-l

l-9.

l-11. SPECIFICATIONS ..................... l-l

2. INITAL PREPARATION ...................... 2-l

2-l. INTRODUCTION ...................... 2-l

2-3.

2.5.

2-7. MODEL 1792 INSTALLATION. ................ 2-3

2-9. Fidel 1792 Output Connections. ............ 2-3

2-11. IIODEL 6422 INSTALLATION. ................

3.
3-l.
3-3.

3-9. CIRCUIT DESCRIPTION. .................. 3-3

3-11.
3-14
3-16.
3-18.
3-20.

3-22. DC-to-DC Converter .................. 3-5

3-24 TEST POINT DATA. .................... 3-5

3-26.

4.

4-l. GENERAL. ........................ 4-l

4-3.
4-5.
4-7.

GENERAL INFORMATION ................... l-l

INTRODUCTION ...................... l-l

SAFETY SYMBOLS ..................... l-l

UNPACKING AND INSPECTION ................ 2-l

PREPARATION FOR USE. .................. 2-l

GPERATION ....................... .3-l

INTRODUCTION ...................... 3-l

OVERALL OPERATION. ...................

Control Circuitry. ..................

Switching Circuitry. ................. 3-4

Isolator Network ................... 3-4

Busy/Hold Circuit. .................. 3-4

Output Registers And Buffers ............. 3-5

SPECIAL HANDLING OF STATIC SENSITIVE DEVICES ......

REPLACEMENTPARTS ...................

ORDERING INFORMATION ..................

SCHEMATIC. ....................... 4-l

COM’ONENT LAYOUT ....................

PAGE

2-4

3-l

3-3

3-6
4-l

4-l

4-l

FIGURE

2-l
2-2
3-1
3-2
3-3
3-4

I LLUSTRATI GNS

TITLE PAGE

Installation of Model 1792 ............... 2-2

Installation of Model 6422 ............... 2-5

Model 1792/6422 Block Diagram. ............... 3-l

Timing Diagram ..................... 3-2

Ring Counter and Gating. ................ 3-3

Busy/Hold Circuit. ................... 3-4

UODELS 1792, 6422

GENERAL INFORMATION

SECTION 1 GENERAL lNFGRMATI(%

l-l. I NTRODUCT I ON.

l-2.
output options that convert displayed meter readings
to electrically isolated, latched, and buffered per­al lel 8CD outputs.

printers or other external data hand1 ing equipment.
Logic
Output data includes sign and overrange signals. In
addition,
meter is updating data.

signal is normally used to initiate a print or load
operation at the listening device. An input control

I ine (HOLD) al lows the listening device to inhibit
the update of output data. When this line is high,
the data update rate is the same as the meter

conversion rate,
Operating characteristics for the Models

1792 are given in their respective Specification
Tables (Table l-l and l-2).
either factory or field installed.

installation procedures are provided in this manual,

because of the different mounting and output cabling

provisions of the options.

l-3. CGf+‘ATIBILITY.

l-4.
are

I nstr unents:

The Models 1792 and 6422 are isolated BCD

These can be appl ied to I ine

levels are TTL/DTL and CMOS compatible.

a BUSY control I i ne indicates that the

The trailing edge of this

typically 2.5 readings/second.

6422 and

Both options can be

Separate

The Model s 1792 and 6422 interface options

compatible with the following Keithley

Model 6422

Model 642 Electrometer Serial Nunber 53402A and
above.

Mode I 1792

Model 179 DMFl Serial Nunber 20000 and above.
Model 179-20A DMFl all Serial Numbers.
Model 177 DMM Serial Nunber 14500 and above.
Model 480 Picoammeter Serial Nunber 12000 and
above. Note:
same as Model 480 display.

First 3-l/2 digits at BCD auf-put

WARRANlY INFGRMATIOIJ.

l-5.

l-6.
cover of this Instruction Manual. If there is a
need to exercise the warranty, contact the Keithley
Representative in your area to determine the proper
action to be taken.
cilities in the United Kingdom and West Germany, as
well as in the
front cover of this Manual for addresses.

l-7.

l-8.
occur after printing of the Instruction Manual will
be explained on a Change Notice sheet attached to

the inside back cover.

l-9. SAFETY SYMOBCLS

l-10.
fol lows:

equipment.
these precautions are ignored.

1-11. SPECIFICATIONS.

l-12.

and 6422 are given
respectively.

The Warranty is given on the inside front

Keithley maintains service fa-

United States. Check the inside

CHANGE NOTICES.

Improvements or changes to the equipment which

Safety symobls used in thls manual are as

IM3oRTANT

The ! n symbol can be found in various places in
this manual. Careful ly read the associated CAU­TION statements with regard to proper use and

handling of the equipment. Damage to the equip-

ment may occur if these precautions are ignored.

This

t

this manual.
the equipment which are potential shock hazards.
Careful ly read the associated WARNING statements

with regard to proper use and hand1 Ing of the

symbol can be found In various places in

This symbol indicates those areas on

Serious personal injury may result if

Detailed specifications for the Model 1792

In Tables l-l and 1-2,

l-l

GENERAL INFORMATION

MODELS 1792, 6422

SPECIFICATIONS

TABLE I-1

SPECIFICATIONS, MODEL 1792 ISOLATED BCD OUTPUT

OUTPUTS : 4-l/2 digit parallel BCD, polarity,

overrange bit, busy.

BUSY:

OUTPUT UPDATE RATE:

CONTROL : E inhibits subsequent output updates

LOGIC LEVELS: TTL/DTL and CMOS compatible.

ISOLATION:

ENVIRONMENT: Operate 0 to 55”C, 0 to 805 RH.

OUTPUT CONNECTOR:

INSTALLATION: Field installable, mounts within

Low during output update (5Oms max).

Same as meter conversion rate

(2.5 reading/second typical).

when low.

Output High = 4.5V minimum while

sourcing lOOkA.

Low =

0.5V maximum while
sinking 3.2mA.

Control High = open or 4V minimum.

Low =

All outputs and controls isolated from
meter up to 1400V peak, 105V*Hz.

(lOlO, ,ll40pf typ1

Storage’ -25 to 7O’C.

26 pin card edge, mates with

CS294-1 (3M 3462 or equivalent)

and powered from Keithley meter.
Adds 0.2kg (0.51 bs).
Precludes Mode I 1788 battery pack

installation.

.5V maximum while

sinking 1mA.

TABLE l-2

SPECIFICATIONS, MODEL 6422 ISOLATED BCD OUTPUT

OUTPUT:

BUSY: Low during output update (50111s max).

OUTPUT UPDATE RATE:

CONTROL : HOLD inhibits subsequent output updates

LOGIC LEVELS:

I SOLAT I ON :

ENVIRONMENT:

OUTPUT CONNECTOR: 26 pin ribbon cable, unterminated.

INSTALLATION:
powered from Keithley meter. Adds 0.4kg (1.0 Lbs).
Precludes Model 6428 battery adapter

installation.

4-l/2 digit parallel BCD, polarity,
overrange bit, busy.

Same as meter conversion
rate (2.5 reading/second
typical).

when low.

TTL/DTL and CF%X compatible.
Output High = 4.5V minimum while

sourcing lOOpA.

Low = 0.5 maxlmum while

sinking 1 mA

Control High = open or 4V minimum.

Low = .5V maximum while

sinking 3.2mA

All outputs and controls isolated from
meter up to 30V peak, 105VoHz.

(lolon II ,4OPf tYP)

Operate 20°C to 30°C
Storage -25°C to +55’C.

Field installable, mounts within and

ASSESSORIES AVAILABLE: Model 1796 - 10’ ou-t-

put mating cable, one end unter-

minated.

Model 1797 - 10’ intercon-

nect cable to 750/7502 printer.

l-2

MODELS 1792. 6422

INITIAL PREPARATION

SECTION 2. INITIAL PREPARATION.

2-l. INTRCOUCTION.

This section provides information for r(ncomlng

2-2.

inspection and preparation for use of your Model
1792/6422 BCD output option.

UNPACKING AND INSPECTION.

2-3.

2-4. The Model 1792/6422 was careful ly inspected,

both mechanically and electrically before ship­ment.
pack all items from the Sh i ppingcontainer and
check for any obvious damage which may have oc­cured during transit.
shipping agent. Retain and use the original
packaging materials if reshipment is required.
The following items (Keithley Part No. in paren­theses) are shipped with al I orders of your
option:

Model 1792

Model 6422

Upon receiving your BCD output option, un-

Report any damages to the

a - PC-498 and shield Assembly

1) PC-488 Assembly (29961D)

2) Shield Assembly (30108C)

Replacement Top Cover (30136C)

b.

­c. A copy of this Instruction Manual (30155)

­d. - Separate Optional Cable (Model 1796 or

1797), as ordered.

a. Assembled PC Board (299610) with modif ied PC-

­498 (301658).

Shield (301328).

b.

-

5 Output Cable assembly with back panel and

strain rel iefs.

I) Cable assembly (302348-l)

2) Back panel (301318).

3) Two strain reliefs (27686A).

d

-. Mounting Hardware

I) Eight Standoffs (ST-94).

2) Eight 6-32 X 5/16” screws.

8. - A copy of this Instruction Manual (30155).

2-5. PREPARATION FOR USE.

2-6. The

for installation.
are provided.

instrument using

procedure.

1792/6422

FUNCTION

Common
Common
HOLD ( Input)
BUSY

Dl-B (2)
Dl-A (1)
Dl-0 (8)
01-C (4)
02-B (2)
02-A (1)
02-D (8)

02-C (4)
03-B (2)
D3-A (1)
D3-D (8)
D3-C (4)
04-B (2)
04-A (1)
04-D (8)
D4-C (4)

Common

05

Overrange

Sign

Common
Common

*Part of 6422 cable assembly or optional Model 1796
cable assembly.

Models 1792 and 6422

Separate installation procedures

Install the Model 1792/6422 in your

the

appl icable

TABLE 2-l

MODEL 1792/6422 Output Connections

P40 1 cs-294- 1 CABLE*

PIN NO.

1 1 1 BRN
2 2 2 RED
3 3 3 ORN
4 4 4 YEL
5 5 5 GRN
6 6 6 BLUE

7 7 7 VI0
8 8 8 GRAY
9 9 9 WHT

10 10 10 BLK
11 11 11 BRN
12 12 12 RED
13 13 13 ORN

’

14 14 14 YEL

15 15 15 GRN

16 16 16 BLUE

17 17 17 VI0
18 18 18 GRAY
19 19 19 WHT

20 20 20 BLK
21 21 21 BRN
22 22 22 RED
23 23 23 ORN
24 24 24 YEL
25 25 25 GRN
26 26 26 BLUE

PIN NO

are

WI RE NO. b COLOR

shipped ready

installation

2-l

\NITIAL PREPARATION

MODELS 1792, 6422

CARD-EDGE .
CONNECTOR

I I

PIN 2 (TOP)

PIN 1 (UNDERNEATH)

-

,-Model 1792

;+ \P1?08

\GROUNF CLIP :

1

2-2

PL

ASTIC SPACER

(4 PLACES)

FIGURE 2-l.

1792-0023-A

Installation of Model 1792.