Unitec Portal Installation Manual - Manual (Page 31)

P O R T A L T I
Portal Installation Manual Rev C 27
Document #: PTL1001
3.8 Intercom Systems
3.8.1 Overview
The use of an intercom system allows two-way communications between customers
at the Portal and staff elsewhere on site. A customer activates the Portal’s intercom
output by pressing the help button. Without an intercom, the intercom output can be
used to activate a bell, light or other device to alert an attendant that help is needed.
The intercom wires connect to the Display IO board on the back of the main door.
Jumpers and adjustments to control its operation are also located on that board. 2, 3,
and 4 wire intercoms are supported. A digital intercom is recommended if the
intercom wiring is sharing conduit with other communications wiring, but not required.
Unitec does not supply intercom systems.
3.8.2 Intercom Connections
The Intercom has two connectors which control the way in which the intercom is
wired and the mode of operation. J34 is the interface and connects to the customer’s
intercom unit. J35 is used to select mode of operation (two, three, or four wire
intercom systems). Twisted pair / fully shielded cable is recommended for optimum
performance.
3.8.3 Intercom Adjustments
The Intercom system has the ability to sense when voice band audio signals are
present. This allows the speakers in the unit to revert to a passive intercom mode.
This bypasses the internal audio section and allows the left speaker to be used as an
intercom. The sensitivity and time delay of this mode can be adjusted according to
the local acoustical characteristics, such as background noise.
• Sensitivity Adjustment: R169 is used to adjust the sensitivity of this
circuit. A green LED below the label “SENS” will aid in the Sensitivity
Adjustment.
• Time-Out Delay Adjustment: R144 is used to adjust the time-out delay
after which the XPT will revert back to the normal audio mode. A green
LED below the label “DELAY” will aid in the Time-Out Delay Adjustment.
Adjust R144 to the desired delay after the last audio has been detected.
Thirty seconds is normal.