Error Condition: Driver error.
Description: EDVR is returned when GPIB hardware is not configured properly, or the interface name or device name passed to the ibfind function is incorrect.
Possible Cause: Often EDVR errors are caused when you misspell the interface name of your board or the device name of your instrument. For example, the default interface name for NI boards is GPIB0, but you may misspell it as GPIBO (with an "oh" instead of a zero). This error may also occur if the board index passed to the ibdev function is incorrect. The board index is the number portion of the interface name for the GPIB board, but many people make the incorrect assumption that it is the primary address of the board. For example, I may install a PCI-GPIB board in my computer and give a primary address of 2. The default interface name for board is GPIB0, so it has a board index of 0, not 2.
- Use the default settings for your GPIB hardware in the GPIB Configuration Utility (i.e., GPIB0 for the interface name and zero for the primary address).
- Use the ibdev function instead of the ibfind function to open communications with your instrument (to avoid using its device name).
- If you must use device names for your instruments, then make sure they are correctly configured in the Device Templates of the GPIB Configuration Utility (see your NI-488.2 User Manual for more details).
- Use the unit descriptor returned from ibdev or ibfind as the first parameter in subsequent NI-488 functions. Examine the variable before the failing function to make sure its value has not been corrupted.