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.