Specifications

IMPORTANT: The polarity of the Tip & Ring contacts of the RJ11 jack for the Tel Line and Over Ride were chosen
so that when a standard modular cord (one with the tops of both end plugs on the same side of the flat cable) is used
to connect the PCM to a modular wall block, the modular block G (Tip) terminal will be positive with respect to the
R (Ring) terminal. Because of variations in types of modular cords and when stripping a modular cord for direct
connection, always check the polarity of the center conductors or R & G terminals to determine Tip & Ring (the
positive lead is Tip and the negative lead is Ring).
5.3. PBX Ground Start Trunk Port
In this configuration, the unit supplies 48V talk battery and loop current detector. When the ground start trunk
grounds Ring, the unit responds by closing the connection to Tip, which completes the access procedure. When the
loop is opened, the page ends. The unit follows the status of the trunk; default and VOX timers are not used in this
mode.
1. Make sure that power is off and all connection completed before proceeding.
2. Move the dip switches on the module to the position shown in Figure 5-3 below. Use the tip of a pen or other
pointed instrument to move the switches.
Figure 5-3: Ground Start
Telephone Selector Switch
3. Use a modular telephone cord to connect the module to the phone system. Plug one end of the cord into the
Ground Start Trunk (using a modular jack) and the other end in to the TEL LINE jack on the module.
The center two conductors are Tip and Ring (48V DC) and are polarity sensitive. If the polarity of the trunk is
opposite, you can use a reversing modular cord to make the connection or reverse the connection through a modular
block. Refer to Figure 5-4 for more information.
Figure 5-4: Loop Start RJ11
Connections
IMPORTANT: The polarity of the Tip & Ring contacts of the RJ11 jack for the Tel Line and Over Ride were chosen
so that when a standard modular cord (one with the tops of both end plugs on the same side of the flat cable) is used
to connect the PCM to a modular wall block, the modular block G (Tip) terminal will be positive with respect to the
R (Ring) terminal. Because of variations in types of modular cords, and when stripping a modular cord for direct
connection, always check the polarity of the center conductors or R & G terminals to determine Tip & Ring (the
positive lead is Tip and the negative lead is Ring).
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