Agilent Technologies E3640-90001 Using *STB? to Read the Status Byte , Using the Message Available Bit (MAV), To Interrupt Your Bus Controller Using SRQ

Chapter 4 Remote Interface Reference
The SCPI Status Registers
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Using *STB? to Read the Status Byte
The *STB? (Status Byte query) command is similar to a serial poll but it is
processed like any other instrument command. The *STB? command returns
the sa m e result a s a seria l poll bu t the “re quest serv ice” b it (bit 6) is not c leared .
The *STB? command is not handled automatically by the IEEE-488 bus
interface hardware and will be executed only after previous commands have
completed. Polling is not possible using the *STB? command. Executing the
*STB? command does not clear the Status Byte summary register.
Using the Message Available Bit (MAV)
You can use the Status Byte “message available” bit (bit 4) to determine when
data is available to read into your bus controller. The power supply
subsequently clears bit 4 only after all messages have been read from the
output buffer.
To Interrupt Your Bus Controller Using SRQ
1Send a device clear message to clear the power supply’s output buffer
(e.g., CLEAR 705).
2Clear the event registers with the *CLS (clear status) command.
3Set up the enable register masks. Execute the *ESE command to set up
the Standard Event register and the *SRE command for the Status Byte.
4Send the *OPC? (operation complete query) command and enter the
result to ensure synchronization.
5Enable your bus controller’s IEEE-488 SRQ interrupt.