Maxim Integrated 73M1822/73M1922 Control Module - Manual (Page 30)

73M1822/73M1922 Control Module User Guide UG_1x22_053
30 Rev. 1.0
6.2.2 M1X22_POL_GET
Description
Gets the current polarity reversal status of the modem line. The driver maintains this status in its local
variable and it is being retrieved by user application using this command.
#define M1X22_POL_GET _IOWR(0xA4,0xB7,unsigned int)
Prototype
int ioctl (
int chan_fd,
int M1X22_POL_GET,
unsigned long param );
Parameters
Data Type Name Description
int chan_fd Channel descriptor.
int M1X22_POL_GET I/O control identifier for this operation.
unsigned long param N/A.
Return Values
Data Type Description
int The return value can be either of the following:
0 – No polarity reversal event.
1 – polarity reversal event occurred on the modem line.