8 loopback services, Loopback services, M1x22_loopback – Maxim Integrated 73M1822/73M1922 Control Module User Manual
Page 55: Section 6.8.1

UG_1x22_053
73M1822/73M1922 Control Module User Guide
Rev. 1.0
55
6.8 Loopback Services
6.8.1 M1X22_LOOPBACK
Description
This IOCTL is used for managing the loopback session – initiating, clearing or retrieving the status of
current active loopback session on a given channel. Only one loopback session can be active per
channel. For reading the status the loopback “mode” will be returned in the structure
M1X22_LOOPBACK_t
pointed to by the “param” field.
#define M1X22_LOOPBACK _IOWR(0xA4, 0xBD, unsigned int)
Prototype
int ioctl (
int chan_fd,
int M1X22_LOOPBACK,
unsigned long param );
Parameters
Data Type
Name
Description
int
chan_fd
Channel descriptor.
int
M1X22_LOOPBACK
I/O control identifier for this operation.
unsigned long param
Pointer to structure M1X22_LOOPBACK_t.
Return Values
Data Type
Description
unsigned int
0 – Successful.
-FAULT – Failed to perform loopback request.