gr 1225 reapeter with maxtrac and radiud 120

[ninfreak]

need help to know how this setup works I found a Repeater gr1225 it is connect to the maxtrac from the gr1225 rj45 front port to the back of the maxtrac 16 pin accessory then the max track rj45 front port to the the back of the radius m120 16 pin accessory the maxtrac has sys1 sys2 subA subB leds and buttons system and subfleet on front its and old setup and I have little know how’s with Repeater