FindLstn Function

Owning Palette: GPIB 488.2 Functions

Requires: Base Development System

Finds all Listeners on the GPIB.

FindLstn detects the presence of devices at particular addresses because most GPIB devices have the ability to listen. When you detect the devices, you can usually interrogate them to determine their identity.

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 tests for the presence of a Listener for all devices listed in address list. If the function does not detect a listening device at the particular primary address, it tests all the secondary addresses associated with that primary address. If a secondary address is required, use the MakeAddr function to put the primary and secondary addresses in the proper format.
	limit If more Listeners are present on the bus than limit specifies, the function truncates listener address list after limit entries.
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	listener address list contains the addresses of all the Listeners the function finds.
	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 Bit Numeric Value Symbolic Status Description 0 1 DCAS Device Clear state 1 2 DTAS Device Trigger State 2 4 LACS Listener Active 3 8 TACS Talker Active 4 16 ATN Attention Asserted 5 32 CIC Controller-In-Charge 6 64 REM Remote State 7 128 LOK Lockout State 8 256 CMPL Operation Completed 12 4096 SRQI SRQ Detected while CIC 13 8192 END EOI or EOS Detected 14 16384 TIMO Timeout 15 -32768 ERR Error Detected
	number of listeners contains the number of addresses placed in listener address list.
	error out contains error information. This output provides standard error out functionality.