8588A/8558A
Remote Programmer's Manual
4
Service Request Line (SRQ)
Service Request (SRQ) is an IEEE-488.1 (GPIB) bus control line that the Product
asserts to notify the controller that it requires some type of service. Service
request is not available if the control interface is Ethernet. Many devices can be
simultaneously connected to the bus, but they all share a single SRQ line. To
determine which instrument set SRQ, the Controller normally does a serial poll of
each instrument. A device connected to the same GPIB bus asserts an SRQ
whenever the RQS bit in its Status Byte Register is 1. This bit informs the
controller that the device was the source of the SRQ. The device clears its RQS
register and clears the SRQ line when the controller does a serial poll of the
device, sends *CLS, or when the MSS bit is cleared. The MSS bit is cleared only
when ESB, MAV, OPER, QUES, and the Error/Event queue summary bits are 0,
or they are disabled by their associated enable bits in the SRE register being set
to 0.
The SCPI Status Registers are described in the STATus subsystem below.
Table 3. IEEE-488.2 (GPIB) Common Command Summary
*CLS
Clear status byte summary, and all event registers
*ESE <enable
value>
Enable bits in standard event register
*ESE?
Retrieve standard event enable register
*ESR?
Retrieve standard event register
*IDN?
Retrieve meter’s identification string
*OPC
Set ‘Operation Complete” bit in Standard event reg.
*OPC?
Returns “1” in output buffer after command execution
*OPT?
Retrieve the options
*PSC {0|1}
Power-on status clear OFF or ON
*PSC?
Retrieve power-on status clear setting
*RST
Reset to power-on state
*SRE <enable
value>
Enable bits in status byte register
*SRE?
Retrieve bits in status byte register
*STB?
Retrieve the status byte summary register
*TRG
Trigger a reading
*TST?
Perform self-test. Returns “0” if the test succeeds, “1” if the test fails
*WAI
Wait for operation complete
