Avaya LUPCMALL, Инструкция по установке и эксплуатации, Страница: 14 / 68

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5.3. PBX Ground Start Trunk Port
In this configuration, the PCM unit supplies a 48V talk battery and loop current detection from pins 3 & 4 of the TRUNK
jack on the PCMTIM module to the ground start trunk in the telephone system. There are two modes of operation for
ground start trunk.
(1) 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. Pins 1, 2, 5 & 6 are not used in this configuration.
Note: Default and VOX timers are not used in this mode.
(2) The unit will operate as in mode one, except it will also provide a one-second hook
flash after the expiration of the VOX and/or Default timers. Operation in this mode
will enable the unit to automatically disconnect itself from the ground start trunk of
the PBX. This will prevent the paging system from being locked up indefinitely in
the event a telephone is accidentally left off hook after a page has been completed.
The feature codes are 014 to inhibit and 015 to enable this feature. The default
feature code is 014 (OFF).
1. Make sure that power is off and all connections completed before proceeding.
2. Move the SLIDE switches on the module to the position shown in Figure 5-3.
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 TRUNK 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.
IMPORTANT:
The polarity of the Tip & Ring contacts of the RJ11 jack for the Trunk and Override 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).
4. Use 24-gauge solid wire to connect the GS terminal on the module to the PBX ground. This is typically the AC ground
for the PBX system.
IMPORTANT: It is very important that no other terminals of the PCM system connect to AC ground when using the ground
start interface. Also, the case of the PCM system cannot be connected to AC ground. If the system is not working and no PCM
terminals (except the GS terminal) are directly connected to AC ground, there may be an indirect connection. Check the
connections to any equipment with a 3-wire AC plug. Make sure that unbalanced inputs and outputs of this equipment are
isolated using a model LUWMT1A transformer (Com Code 405891680) before connecting the equipment to the PCM.
The PA OUT and HPBGM terminals on the PCM do not have to be ground-isolated.
Figure 5-3: Ground Start
Telephone Selector Switches
Figure 5-4: Loop Start
RJ11 Connections