Measurement Computing GPIB-488 - Manual (Page 76)

Chapter 4 GPIB 488.2 Library Reference
Programming Reference Manual 4-8 GPIB-488
FindRQS
Identify the device requesting service.
Syntax
C FindRQS(int board, short addresslist[], short
*result)
Parameters
board is an integer which identifies the GPIB board to be used for this operation. In most
applications, this value is 0.
addresslist is an array of GPIB addresses, terminated by the value NOADDR . The devices
located at these addresses are serial polled until the one asserting SRQ is located.
Returns
result will contain the returned status byte of the device asserting SRQ.
ibcnt will contain the index (in addresslist ) identifying the device's address.
ibsta will contain a 16-bit status word as described in Appendix B, IBSTA .
iberr will contain an error code, if an error occurred. iberr contains the error code ETAB ,
if no device is requesting service. In this case, ibcn t contains NOADDR 's index.
iberr will contain the error code EABO if a device times out while responding to its serial
poll. In this case, ibcnt contains the index of the timed-out device.
Usage Notes
None.
Example
Identifies which of the devices at GPIB addresses 6 and 7 (connected to board 0) is requesting
service.
C
short addresslist[3] = {6,7,NOADDR};
short result;
FindRQS (0, addresslist, &result);