IST flag and PPE
Note, that the sophisticated parallel poll function is only useful with GPIB interfaces and requires traditional GPIB drivers.
Similar to the service request (SRQ), the IST flag combines the entire status information in a single bit. It can be queried via a parallel poll.
The parallel poll enable (PPE) register determines which bits of the STB contribute to the IST flag. The bits of the STB are combined via a logical AND operation with the corresponding bits of the PPE. In contrast to the SRE, bit 6 is also considered. The resulting bits are combined via an OR operation to determine the IST flag.
Related common commands
The IST flag is queried using the *IST? command.
The PPE can be set using *PRE and read using the *PRE? command.