Rohde & Schwarz CMW500 Series, User Manual

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Remote Control
R&S
®
CMW500
166 User Manual 1173.9463.02 ─ 02
6.5.4 Status Reporting System
The status reporting system collects information on the instrument state and makes it
available to the output unit on request. The exact structure and function are described in
section
Status Reporting System .
6.5.5 Output Unit
The output unit collects the information requested by the controller, which it receives from
the data set management. It processes it according to the SCPI rules and makes it avail-
able in the output buffer. If the information requested is longer, it is made available "in
portions" without this being recognized by the controller.
If the instrument is addressed as a talker without the output buffer containing data or
awaiting data from the data set management, the output unit sends the error message
"Query UNTERMINATED" to the status reporting system. No data is sent on the GPIB
bus or via the Ethernet, the controller waits until it has reached its time limit. This behavior
is specified by SCPI.
6.6 Status Reporting System
The status reporting system stores all information on the present operating state of the
instrument, and on errors which have occurred. This information is stored in the status
registers and in the error queue. Both can be queried using the
STATus Commands .
Hierarchy of status registers
As shown in section Overview of Status Registers , the status information is of hierarchical
structure.
●
STB, SRE:
The STatus Byte (STB) register and its associated mask register Service Request
Enable (SRE) form the highest level of the status reporting system. The STB provides
a rough overview of the instrument status, collecting the information of the lower-level
registers.
●
The STB receives its information from:
The Event Status Register (ESR) with the associated mask register standard Event
Status Enable (ESE).
The STATus:OPERation and STATus:QUEStionable registers which are defined by
SCPI and contain detailed information on the instrument.
●
IST, PPE:
The IST flag ("Individual STatus"), like the SRQ, combines the entire instrument sta-
tus in a single bit. The PPE is associated to the IST flag. It fulfills an analogous function
for the IST flag as the SRE does for the service request.
●
Output buffer:
contains the messages the instrument returns to the controller. It is not part of the
status reporting system but determines the value of the MAV bit in the STB.
Status Reporting System