Status Byte Register (Stb); Service Request Enable Register (Sre); Reading The Stb By Detecting Srq; Reading The Stb By "*Stb?" Command - THORLABS ITC8 Series Operation Manual

64 Status reporting
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3.4.3 Status byte register (STB)

The bits of this register are showing the status of the PRO8000 (-4) / PRO800.
RQS
MSS
MAV
DES
EAV
FIN
The STB can be read directly with the command
cannot be set. The bits are active high.
All bits except bit 6 of the STB can be used to assert a service request (SRQ) (see
3.4.5). Alternatively the SRQ can be recognized using the command
"*STB?"
(see 3.4.6) or by serial poll (see 3.4.7).

3.4.4 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 combinedned by a logical "OR", so that any "hit"
leads to a logical 1 in bit 6 of the STB and asserts an SRQ.

3.4.5 Reading the STB by detecting SRQ

If an SRQ is asserted (see 3.4.4) bit 6 of the STB is set to logical 1, so that the
controller can detect which device asserted the SRQ by auto serial polling.
3.4.6 Reading the STB by
If the controller does not "listen" to SRQ's at all, the service request can be detected
by reading the status byte with the command
If bit 6 is logical 1, a service request was asserted.
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RQS: Request service message: Shows, that this device
has asserted SRQ (read via serial poll).
Master summary status: Shows that this device requests a
"*STB?"
service (read via
(Message AVailable) This bit is high after a query request,
as a result "waits" in the output queue to be fetched. It is
low, if the output queue is empty.
(Device Error Status) This bit is high after a device error
occurred. Which device errors will set this bit is defined
with the EDE.
(Error AVailable) This bit is high as long as there are
errors in the error queue.
(command FINished) This bit is high, after a command has
finished and all bits of the STB have been set.
"*STB?" command
).
"*STB?". The content of the STB
"*STB?".
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