Operation of the GPIB Appendix E

GPIB-1014 User Manual E-4 © National Instruments Corporation

Physical and Electrical Characteristics

Devices are usually connected with a cable assembly consisting of a shielded 24 conductor cable

with both a plug and receptacle connector at each end. This design allows devices to be linked in

either a linear or a star configuration, or a combination of the two. See Figures E-1, E-2, and E-3.

The standard connector is the Amphenol or Cinch Series 57 Microribbon or Amp Champ type. An

adapter cable using a non-standard cable and/or connector is used for special interconnection

applications.

The GPIB uses negative logic with standard TTL logic level. When DAV is true, for example, it is

a TTL low level ( 0.8V), and when DAV is false, it is a TTL high level ( 2.0V).

DIO1*
DIO2*
DIO3*
DIO4*
EOI*
DAV*
NRFD*
NDAC*
IFC*
SRQ*
ATN*
SHIELD
DIO5*
DIO6*
DIO7*
DIO8*
REN*
GND (TW PAIR W/DAV*)
GND (TW PAIR W/NRFD*)
GND (TW PAIR W/NDAC*)
GND (TW PAIR W/IFC*)
GND (TW PAIR W/SRQ*)
GND (TW PAIR W/ATN*)
SIGNAL GROUND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

Figure E-1. The GPIB Connector and Signal Assignments