To use on or two M-Link receivers with a SRS prduct (iGyro, Mercury SRS, Cockpit SRS, Royal SRS...) you have to set the Data oputput of the receivers to "SRXL". To do that, you need a USB interface adapter from Multiplex or PowerBox.
You can download the free software from the Multiplex Website: MPX Launcher When the program is installed - proceed with following steps:
When using two receivers: set the Hold and Failsafe Time top 0.2s and 0.0s
The receiver is now ready to connect to the PowerBox SRS.