Specifications

4. Use 24-gauge solid wire to connect the GND ST 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 GND ST 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 LUWMTIA transformer (Corn 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.
5.4. PBX Page Port
In this configuration, the unit responds to a contact shorting the closure source to its return. When the short is
removed, the page ends. Audio is provided to the system through a separate pair of leads.
1. Make sure that power is off and all connections completed before proceeding.
NOTE:
Make sure that the page port produces DTMF tones. The page port must also be hi-directional in order to use
talk back.
2. Move the dip switches on the module to the position shown in Figure 5-5 below. Use the tip of a pen or other
pointed instrument to move the switches.
Figure 5-5: Page Port
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 Page
Port and the other end in to the TEL LINE jack on the module.
The center two conductors are used for dry audio and the connectors on either side are connected to the page port
contact closure. The maximum resistance of the page port contact closure is 1000 ohms. Refer to Figure 5-6 below for
more information.
Figure 5-6: Page Port
RJ11 Connections
5.5. PBX Analog Station Port
In this configuration, the unit answers after the first full ring. As soon as it answers, the default timer is started. The
default timer determines the maximum length of any page. When a paging zone is selected, the VOX timer is started
(if enabled). This timer repeatedly resets as long as audio is detected on the line. If no audio is detected within the
VOX time period, the page will end. If audio continues to be detected, the default timer will control page length.
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