The MOH port and Pager port are SELV ports and should only be connected to approved SELV devices,
or in Australia, via a Line Isolation Unit with a Telecommunications Compliance Label.
To protect the system, keep the following in mind:
Make sure that both connector cases (frame ground) of the RS-232C cross cable (shielded cable) are
conductive. If they are not conductive, make sure that both connector cases of the cable are firmly
If this is not possible, connect the frame of the PBX to the frame of the PC/Printer using an earthing
wire in order to prevent difference in the electrical potentials.
1.1 For Your Safety