G-6 IEEE-488 and SCPI Conformance Information Model 6485 Picoammeter Instruction Manual
NDAC hold-off
NDAC hold-off is included with the GPIB 488.1 protocol mode to allow a single instru-
ment to hold off all others on the bus until it is finished executing a command. The follow-
ing command controls NDAC hold-off:
SYSTem:MEP:HOLDoff ON | OFF
The default is OFF, but NRFD hold-off will still be enabled and will prevent an instrument
from accepting further commands. See Figure G-1 for the complete IEEE-488 handshake
sequence.
Figure G-1
IEEE-488 handshake sequence
DATA
DAV
SOURCE
SOURCE
VALID
ALL READY
ACCEPTOR
NRFD
NDAC
ALL ACCEPTED
ACCEPTOR
To Next Page
Loading...
