Initialization Functions - Rockwell Automation Allen-Bradley ControlLogix 1756-MVI Programming Reference Manual

3-6 MVI Backplane API
Publication 1756-RM004B-EN-P - October 2000

Initialization Functions

MVIbp_Open
Syntax:
int MVIbp_Open(MVIHANDLE *handle);
Parameters:
handle pointer to variable of type MVIHANDLE
Description:
MVIbp_Open acquires access to the API and sets handle to a unique ID
that the application uses in subsequent functions. This function must be
called before any of the other API functions can be used.
Once the API has been opened, MVIbp_Close should
IMPORTANT
always be called before exiting the application.
Return Value:
MVI_SUCCESS
MVI_ERR_REOPEN
MVI_ERR_NODEVICE
Note: MVI_ERR_NODEVICE will be returned if the backplane device
driver is not loaded.
Example:
MVIHANDLE Handle;
if (MVIbp_Open(&Handle) != MVI_SUCCESS) {
printf("Open failed!\n");
} else {
printf("Open succeeded\n");
See Also:
MVIbp_Close
API was opened successfully
API is already open
backplane driver could not be accessed