Measurement Computing Personal488 rev.3.0 - Manual (Page 73)

Personal488 for Windows 95/98/Me/NT/2000 04-10-01 API Reference 6-5
CheckListener
Syntax INT WINAPI CheckListener(DevHandleT devHandle, BYTE primary,
BYTE secondary);
devHandle refers to either an IEEE 488 hardware interface or an external device. If
devHandle refers to an external device, the CheckListener command acts on the
hardware interface to which the external device is attached.
primary is the primary bus address to check for a Listener ( 00 to 30 )
secondary is the secondary bus address to check for a Listener ( 00 to 31 ). For no
secondary address, a -1 must be specified
Returns -1 if error
otherwise it returns a 1 if a listener was found at the specified address, or a 0 if a listener
was not found at the specified address.
Bus States ATN
•UNL, LAG,
(check for NDAC asserted)
Example result = CheckListener(ieee,15,4);
if (result == 1)
{
printf(“Device found at specified address.\n”);
}
if (result == 0)
{
printf(“Device not found at specified address.\n”);
}
See Also FindListener, BusAddress
The CheckListener command checks for the existence of a device on the IEEE 488 bus at the specified
address.