Rockwell Automation Allen-Bradley ControlLogix 1756-MVI Programming Reference Manual page 103

MVIsp_GetDTR
Syntax:
int MVIsp_GetDTR(int comport, int *state);
Parameters:
comport port for which DTR is requested
state pointer to int for desired state
Description:
This function allows the state of the DTR signal to be determined.
comport must be previously opened with MVIsp_Open. The current
state of the DTR signal is copied to the int pointed to by state.
Return Value:
MVI_SUCCESS
MVI_ERR_NOACCESS
MVI_ERR_BADPARAM
Example:
i
nt state;
if (MVIsp_GetDTR(COM1, &state) = = MVI_SUCCESS)
{
if (state = = ON)
printf("DTR is ON\n");
else
printf("DTR is OFF\n");
}
See Also:
MVIsp_SetDTR
the DTR state was read successfully
comport has not been opened
invalid pointer
Publication 1756-RM004B-EN-P - October 2000
Serial Port API 5-15