National Instruments NI-488.2 - Manual (Page 105)

Appendix C Error Codes and Solutions
NI-488.2 User Manual C-4 ni.com
ENOL (2)
ENOL usually occurs when a write operation is attempted with no
Listeners addressed. For a device write, ENOL indicates that the GPIB
address configured for that device in the software does not match the GPIB
address of any device connected to the bus, that the GPIB cable is not
connected to the device, or that the device is not powered on.
ENOL can occur in situations where the GPIB interface is not the CIC and
the Controller asserts ATN before the write call in progress has ended.
Solutions
Possible solutions for this error are as follows:
• Make sure that the GPIB address of your device matches the GPIB
address of the device to which you want to write data.
• Use the appropriate hex code in ibcmd to address your device.
• Check your cable connections and make sure at least two-thirds of
your devices are powered on.
• Call ibpad (or ibsad , if necessary) to match the configured address
to the device switch settings.
EADR (3)
EADR occurs when the GPIB interface is CIC and is not properly
addressing itself before read and write functions. This error is usually
associated with board-level functions.
EADR is also returned by the function ibgts when the shadow-handshake
feature is requested and the GPIB ATN line is already unasserted. In this
case, the shadow handshake is not possible and the error is returned to
notify you of that fact.
Solutions
Possible solutions for this error are as follows:
• Make sure that the GPIB interface is addressed correctly before calling
ibrd , ibwrt , RcvRespMsg , or SendDataBytes .
• Avoid calling ibgts except immediately after an ibcmd call.
( ibcmd causes ATN to be asserted.)