Serial poll

In a serial poll, the controller queries the status bytes of all instruments in the bus system, one after another, to find out who sent an SRQ and why. The query is implemented using interface messages, so it is faster than a poll via the command *STB.

The serial poll method is defined in IEEE 488.1 and used to be the only standard possibility for different instruments to poll the status byte. The method also works for instruments which do not adhere to SCPI or IEEE 488.2.

The serial poll is used to obtain a fast overview of the state of several instruments connected to the controller.