Service request

The instrument can send a service request (SRQ) to the controller. A service request is a request for information, advice or treatment by the controller. Usually this service request initiates an interrupt at the controller, to which the control program can react appropriately.

An SRQ is always initiated if one or several of bits 2, 3, 4, 5 or 7 of the status byte are set and enabled in the SRE. Each of these bits combines the information of a further register, the error queue or the output buffer.

The ENABle parts of the status registers can be set such that arbitrary bits in an arbitrary status register initiate an SRQ. To use service request effectively, all bits in the enable registers SRE and ESE must be set to "1".

Use of the command *OPC to generate an SRQ at the end of a sweep
  1. *ESE 1: Set bit 0 in the ESE (operation complete).

  2. *SRE 32: Set bit 5 in the SRE (ESB bit). See also Table "Bits in STB register").

  3. *INIT;*OPC: Generate an SRQ after operation complete.

When all commands preceding *OPC have been completed, the instrument generates an SRQ.