National Instruments GPIB-100A - Manual (Page 31)

Operation of the GPIB Appendix A
GPIB-100A User Manual A-6 © National Instruments Corporation
Figure A-3. Star Configuration of GPIB Devices
The standard connector is the Amphenol or Cinch Series 57 MICRORIBBON or AMP CHAMP
type. An adapter cable using non-standard cable and/or connector is used for special interconnect
applications.
The GPIB uses negative logic with standard TTL logic levels. When DAV is true, for example, it
is a TTL low level (
≤
0.8 V), and when DAV is false, it is a TTL high level (
≥
2.0 V).