
Appendix C Error Codes and  Solutions
NI-488.2 User Manual C-2 ni.com
EDVR (0)EDVR is returned when the interface or device name passed to ibfind, 
or the interface index passed to ibdev, cannot be accessed. The global 
variable  ibcntl contains an error code. This error occurs when you try 
to access an interface or device that is not installed or configured properly.
EDVR is also returned if there is an internal driver error.
Solutions
Possible solutions for this error are as follows:
•Use 
ibdev to open a device without specifying its symbolic name.
• Use only device or interface names that are configured in the GPIB 
Configuration utility as parameters to the ibfind function.
• Use the NI-488.2 Troubleshooting Utility to ensure that each interface 
you want to access is working properly, as follows:
Windows
1. Select Start»Programs»Na tional Instruments»
Measurement & Automation.
2. Select Help»Troubleshoot ing»NI-488.2 Troubleshooting Utility.
Mac OS X
Run Applications»National Instruments»NI-488.2»Troubleshoot.
EHDL 23 Input handle is invalid
EWIP 26 Wait in progress on specified input handle
ERST 27 The event notification was cancelled due 
to a reset of the interface
EPWR 28 The interface lost power
Table C-1.  GPIB Error Codes (Continued)
Error 
Mnemonic
iberr 
Valu e Meaning