FindRQS Function

Owning Palette: GPIB 488.2 Functions

Requires: Base Development System

Determines which device is requesting service.

Refer to GPIB Function Defaults for more information about the timeout and address defaults.

 Add to the block diagram  Find on the palette
bus refers to the GPIB bus number. If you have only one GPIB interface in your computer, the default bus number is 0. Refer to the software installation instructions included with the GPIB controller for additional GPIB interfaces.
address list serial polls the GPIB devices listed in address list, starting at the beginning of the address list array, until the function finds the device asserting SRQ. If a secondary address is required, use the MakeAddr function to put the primary and secondary addresses in the proper format.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
requester status byte is the status byte for the device asserting SRQ.
status is a Boolean array in which each bit describes a state of the GPIB Controller. If an error occurs, the function sets bit 15. GPIB error is valid only if bit 15 of status is set.

The following table shows the numeric value and symbolic status of each bit in status. This table also includes a description of each bit.
Status BitNumeric ValueSymbolic StatusDescription
01DCASDevice Clear state
12DTASDevice Trigger State
24LACSListener Active
38TACSTalker Active
416ATNAttention Asserted
532CICController-In-Charge
664REMRemote State
7128LOKLockout State
8256CMPLOperation Completed
124096SRQISRQ Detected while CIC
138192ENDEOI or EOS Detected
1416384TIMOTimeout
15-32768ERRError Detected
requester index is the index of the address in address list of the device asserting SRQ. Arrays are zero-indexed. A requester index of -1 indicates that none of the devices specified in the address list are requesting service.
error out contains error information. This output provides standard error out functionality.