R&S EM510, Manual

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EM510 Remote Control via LAN
4065.7763.32-01.00 5.128
5.5 Status Reporting System
The status reporting system (see Figure 5-5: Overview of status registers) stores all the information on
the present operating state of the device, e.g. that the device presently carries out a SWEeping, and on
errors which have occurred. This information is stored in the status registers and in the error queue. For
each remote client there is a separate status reporting system and access to all registers of the error
queue.
The information is of hierarchical structure. The register status byte
(STB)
defined in IEEE 488.2 and
its associated mask register service request enable (
SRE
) form the uppermost level. The
STB
receives
its information from the standard event status register (
ESR
) which is also defined in IEEE 488.2 with
the associated mask register standard event status enable (
ESE
) and registers
STATus:OPERation
and
STATus:QUEStionable
which are defined by SCPI, the registers
STATus:TRACe
and
STATus:EXTension
not specified by SCPI as well as the two queues error queue and message
queue.
The IST flag ("Individual STatus") and the parallel poll enable register (
PPE
) allocated to it are also part
of the status reporting system. The IST flag, like the SRQ, combines the entire device status in a single
bit. The
PPE
fulfills a function for the IST flag as the
SRE
does for the service request.
The message queue contains the messages the device sends back to the controller. It is not part of the
status reporting system but determines the value of the MAV bit in
STB
and is thus shown in Figure 5-5.