National Instruments GPIB-PC - Manual (Page 231)

Common Errors and Their Solutions Appendix B
GPIB-PC User Manual B-2 ©National Instruments Corp.
ENOL(2)
Error Condition: Write function detected no Listeners.
Solutions:
• Check that the device is powered on, and also that at least two-
thirds of the devices on the GPIB are turned on.
• Inspect the interconnecting cable to see that the devices are
attached and that the connectors are seated properly.
• Check the switches or control panel of the device and make
sure its GPIB address is what you think it is. Check also
whether the device uses extended addressing and requires a
primary and secondary address. (Some devices use multiple
secondary addresses to enable different internal functions).
• For device write functions, run IBCONF from the root directory
and check that the device's address (including secondary
address) is correct. If a change is made, reboot the system.
Then run
IBIC to verify that the address is correct, as follows.
Open the device you want to write to using IBFIND and
execute IBPAD and IBSAD calls, passing each the address
value you believe is correct. If secondary addressing is not
used, pass a value of zero to the
IBSAD function. Assuming
these calls do NOT return with an error, IBIC will return the
previous address value, which will be the same as the new one
if you have correctly configured the device.
• For board write functions, make sure the device is addressed
properly using the
IBCMD function before the write call. Verify
that the low five bits of the listen address (and if appropriate
the secondary address) used in the
IBCMD call match the
device's GPIB address(es) and also that the listen address is in
the range 20-3E hex (32-62 decimal) and the secondary address
is in the range 60-7E hex (92-126 decimal).