3
947137
To rering the same station, press the "*" button. The
station will be signaled as long as the * button is held.
To rering using rotary dial, dial "1". The station will
be signaled for one second each time a "1" is dialed.
To achieve maximum performance from this system,
the user should receive the following operating
instructions:
a.
The calling party should speak directly into
telephone mouthpiece and avoid speaking
too softly.
b.
The called party must wait (approximately
1/2 second) before responding to the calling
party.
CIRCUIT DESCRIPTION
General Method of Operation
This unit provides dial intercom access provisions to
appropriately interface with the telephone system
being used. A two-way amplifier conditions the
speech from the telephone system tip and ring, and
provides a low impedance, low level output to the
desired speaker via conventional telephone wiring,
i.e., house cable or station wire.
Detailed Description
When station user lifts handset to make an ICM page,
the switchhook contacts in the telephone close the tip
and ring to form a loop which returns battery back to
turn on transistor Q1. Transistor Q1 operates relay
and logic circuit to return dial tone and lamp battery
to telephone set. Logic circuit receives dialing
information and operates relays and/or circuitry to
supply splash tone and a two-way voice connection
for station selected. When called or any other party
goes off-hook on ICM path, the presence of two
resistance grounds cancels or turns off speakers if
inhibit resistors are wired. "Handsfree mode" can
only be restored by terminating call and redialing
station.
TECHNICAL ASSISTANCE
When trouble is reported, verify that:
•
All telephone sets are in proper working order
•
Power is being supplied to the unit
•
There are no broken connections at the
connecting block
•
The conductors of color-coded cables are
terminated in the proper order
If trouble still exists, additional checks should be
made using the following equipment:
•
Voltmeter
•
Tone-dial single-line instrument (for tone-dial
systems)
•
Telephone Test Set
•
Clip leads
Test lamps must not be used to check voltages. They
can damage electronic circuits. A telephone test set
should not be used to check voltages; the results will
be misleading.
Before proceeding further, check the voltages at the
connecting block. An undetected blown fuse or low
voltage will cause improper control operation. DC
voltage measurements are made with respect to (+)
ground.
If a spare unit is available, continue to troubleshoot by
substituting the spare unit for the suspected unit. If the
trouble has not been located, refer to Table 1. Identify
the symptoms and perform the corrective actions
indicated. After all the suggested tests have been
performed, the trouble still exists, telephone Valcom,
Inc. at (540) 427-3900 and ask for Technical Support,
or call (540) 427-6000 for Valcom 24-hour Automated
Support or visit our website at
http://www.valcom.com.
Valcom equipment is not field repairable. Valcom,
Inc. maintains service facilities in Roanoke, VA.
Should repairs be necessary, attach a tag to the unit
clearly stating company name, address, phone
number, contact person, and the nature of the
problem. Send the unit to:
Valcom, Inc.
Repair and Return Dept.
5614 Hollins Road
Roanoke, VA 24019-5056
