B&K Precision 4078 - Manual - Manual (Page 90)

4.17 GPIB Communication Protocol
(for models 4075GPIB & 4078GPIB)
4.17.1 General
This appendix describes the effects of interface messages on waveform generator operation and uses abbreviations
from the IEEE Standard 488.1-1987.
4.17.2 Responses to IEEE-488.1 Interface Messages
Interface messages and the effects of those messages on the instrument interface functions are defined in IEEE
Standard 488.1-1987. Where appropriate, the GPIB code is listed, in decimal.
UNL-Unlisten (63 with ATN)
UNT-Untalk (95 with ATN)
The UNL command places the listener function to its idle (unaddressed) state. In this idle state, the waveform
generator cannot accept commands from the GPIB.
The UNT command places the talker function to its idle state. In this idle state, the waveform generator cannot
output data through the GPIB.
When the talker and listener functions are idle, the front-panel ADRS indicator is off. If the waveform generator is
talk-addressed or listen-addressed, the ADRS indicator lights.
IFC-Interface Clear (Bus pin 9)
The IFC message places both the listener and talk functions to idle states. When the talker and listener functions are
idle, the front-panel ADRS indicator is off.
The IFC pulse is >= 100us.
DCL-Device Clear (20 with ATN)
The Device Clear message resets GPIB communication. That is, the DCL message clears all input and output
messages, as well as all unexecuted settings.
SDC-Selected Device Clear (4 with ATN)
The SDC message causes the same response as the DCL message. However, the waveform generator only responds
if it is listen-addressed.
GET-Group Execute Trigger (8 with ATN)
The waveform generator responds to the Group Execute Trigger message only if it is listening addressed and the
device trigger function is enabled. The TRIGger:MODE must be in TRIG, CONTinuous, or BURst and the
TRIGger:SOURce must be set to BUS to enable device triggering via GET.