Specifications

STATus Commands
*OPC?
Returns a 1 to the output buffer when all pending operations complete. The response is delayed until all pending oper-
ations complete.
Parameter Typical Return
(none) 1
Return a 1 when commands complete: *OPC?
l The purpose of this command is to synchronize your application with the instrument.
l Other commands cannot be executed until this command completes.
*SRE <value>
*SRE?
Service Request Enable Command and Query. Sets the value of the Service Request Enable register. This determines
which bits from the Status Byte Register are summed to set the Master Status Summary (MSS) bit and the Request for
Service (RQS) summary bit. A 1 in any Service Request Enable register bit position enables the corresponding Status
Byte register bit. All such enabled bits are then logically OR-ed to cause the MSS bit of the Status Byte register to be set.
Refer to Status Tutorial for more information.
The query reads the enable register and returns a decimal value which corresponds to the binary-weighted sum of all
bits set in the register.
Parameter Typical Return
A decimal value that corresponds to the binary-
weighted sum of the bits in the register.
<bit value>
Enable bit 3 and 4 in the enable register: *SRE 24
l When a serial poll is conducted in response to SRQ, the RQS bit is cleared, but the MSS bit is not.
l When *SRE is cleared (by programming it with 0), the power supply cannot generate an SRQ to the controller.
*STB?
Status Byte Query. Reads the Status Byte Register, which contains the status summary bits and the Output Queue
MAV bit. The Status Byte is a read-only register and the bits are not cleared when it is read. Refer to Status Tutorial for
more information.
Parameter Typical Return
(none) <bit value>
Read status byte: *STB?
92 Agilent N8900 Series Operating and Service Guide