Rohde & Schwarz CMW 500 - IST Flag and PPE

R&S
®
CMW 500 Remote Control
Status Reporting System
Operating Manual 1202.3986.32 – 03 106
summary bit of the remaining bits of the status byte.
SRE and Service Request
The STatus Byte (STB) is linked to the Service Request Enable (SRE) register on a bit-
by-bit basis.
The STB corresponds to the CONDition part of an SCPI register, indicating the
current instrument state.
The SRE corresponds to the ENABle part of an SCPI register. If a bit is set in the
SRE and the associated bit in the STB changes from 0 to 1, a Service Request
(SRQ) is generated on the GPIB bus.
Bit 6 of the SRE is ignored, because it corresponds to the summary bit of the STB.
Related common commands
The STB is read out using the command *STB? or a serial poll.
The SRE can be set using command *SRE and read using *SRE?.
The bits in the STB are defined as follows:
Bit
No.
Meaning
2 Error Queue not empty
This bit is set when an entry is made in the error queue.
3 QUEStionable status summary bit
The bit indicates a questionable instrument status, which can be further pinned down by polling the
QUEStionable register.
4 MAV bit(message available)
This bit is set if a message is available and can be read from the output buffer.
This bit can be used to automatically transfer data from the instrument to the controller.
5 ESB bit
Sum bit of the event status register. It is set if one of the bits in the event status register is set and
enabled in the event status enable register.
Setting of this bit implies an error or an event which can be further pinned down by polling the event
status register.
6 MSS bit (master status summary bit)
This bit is set if the instrument triggers a service request. This is the case if one of the other bits of this
registers is set together with its mask bit in the service request enable register SRE.
7 OPERation status register summary bit
This bit is set if an EVENt bit is set in the OPERation-Status register and the associated ENABle bit is
set to 1.
5.6.3.2 IST Flag and PPE
In analogy to the Service Request (SRQ), the IST flag combines the entire status
information in a single bit. It can be queried by means of a parallel poll.
The Parallel Poll Enable (PPE) register determines which bits of the STB contribute to
深圳德标仪器 135-1095-0799