National Instruments GPIB-110 User Manual page 49

Operation of the GPIB Appendix C
GPIB Cables
Device A
Device D
Device C
Device B
Figure C-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 transistor-transistor logic (TTL) levels.
For example, when DAV is true, it is a TTL low level (≤ 0.8 V), and when DAV is false, it is a
TTL high level (≥ 2.0 V).
GPIB-110 User Manual C-6 © National Instruments Corporation