The Srq Method - Keysight N1911A Programming Manual

Power Meter Remote Operation 1

The SRQ Method

When a bit of the Status Register is set and has been enabled to assert SRQ (*SRE
command), the power meter sets the GPIB SRQ line true. This interrupt can be
used to interrupt your program, suspending its current operation, and find out
what service the power meter requires. Refer to your computer and language
manuals for information on how to program the computer to respond to the
interrupt.
To allow any of the Status Register bits to set the SRQ line true, you must enable
the appropriate bit(s) with the *SRE command. For example, if your application
requires an interrupt whenever a message is available in the output queue (Status
Register bit 4, decimal weight 16). To enable bit 4 to assert SRQ, use the command
*SRE 16.
You can determine which bits are enabled in the Status Register using *SRE?.
NOTE
This command returns the decimal weighted sum of all the bits.
Procedure
– Send a bus device clear message
– Clear the event registers with the *CLS (clear status) command
– Set the *ESE (standard event register) and *SRE (status byte register) enable
masks
– Enable your bus controller's IEEE-488 SRQ interrupt
Examples
The following two examples are written in HP BASIC and illustrate possible uses
for SRQ. In both cases, it is assumed that the power meter has been zeroed and
calibrated.
N1911A/1912A P-Series Power Meters Programming Guide 77