3.8 Status reporting
ITC500 / page 94
All bits except bit 6 of the STB can be used to assert a service request (SRQ)
(Please refer to 3.8.5). Alternatively the SRQ can be recognized using the command
"*STB?"
(Please refer to 3.8.6) or by serial poll (Please refer to 3.8.7).
3.8.4 Service request enable register (SRE)
The bits of the SRE are used to select, which bits of the STB shall assert an SRQ.
Bit 0, 1, 2, 3, 4, 5 and 7 of the STB are related to the according 7 bits of the SRE by
logical “AND”. These 7 results are combined by a logical "OR", so that any "hit" leads
to a logical 1 in bit 6 of the STB and asserts an SRQ.
3.8.5 Reading the STB by detecting SRQ
If an SRQ is asserted (see 3.8.4) bit 6 of the STB is set to logical 1, so that the
controller can detect by auto serial polling, which device asserted the SRQ.
3.8.6 Reading the STB by
*STB?
command
If the controller does not "listen" to SRQs at all, the service request can be detected
by reading the status byte with the command
"*STB?"
.
If bit 6 is logical 1, a service request was asserted.
3.8.7 Reading the STB by serial poll
If the controller does not support auto serial poll, the service request can also be
detected via manual serial poll.
If bit 6 is logical 1, a service request was asserted.
