4
947923
Power Connections
The connections required to connect the
V-9923B to a power supply are shown in
Figure 6. Correct polarity must be observed for
the unit to function properly.
Output Connections
The V-9923B contains a tone generator and
isolation transformer to allow direct hook-up to
the paging system amplifier. The tones are
applied to the output in the coded sequence
dialed into the unit. The tones appear on the TT,
(BK/S, pin 29) and the RT (S/BK, pin 30) leads.
If tones are not required as in the case of using
Claxton horns, bells, buzzers, lamps, etc. a
contact closure is available. The contact is
capable of handling 1 amp @ 125VAC or 2
amps @ 30VDC. Higher current requirements
should use the contact to operate a power relay,
which would switch the load. The switched
make contact input is the IN lead (BL/BK, pin 22)
and the out lead is the OUT lead (BK/BL, pin 21).
When the switched output of the V-9923B is
used to operate a DC slave relay, it is necessary
to install a spike suppression diode in parallel
with the coil of the relay. Refer to Figure 7 for
the appropriate connections.
Option Switches
Four option switches are located through the
back of the unit near the amphenol.
•
Switch 1 sets either two or three digit
operation.
•
Switch 2 allows or disallows the calling
party to hear the tones as they are sent.
•
Switch 3 must be left in the ON position.
•
Switch 4 is for flashing or solid lamp
indication on access (1A2 key systems
only).
*Refer to Figure 8 for Option Switch Settings
Two Link Connection
If more than one V-9923B is being used to
provide two link operation, strap EP1 lead from
first unit to EP2 lead of second unit. Strap EP2
lead of first unit to the EP1 lead of the second
unit. A maximum of two links is all that is
possible.
OPERATION
The code call unit is accessed by placing a
telephone or a resistive short across T and R.
The unit will return dial tone to the calling party
when it is ready to accept digits.
NOTE: In two link operation, dial tone will be
withheld from the second link until the code
call on first link is answered to prevent two
codes being broadcast simultaneously.
The calling party then dials in a two or three digit
number depending upon the position of dipswitch
#1 on the code call unit. After the last digit the
code call unit begins to transmit tone via the TT
and RT leads and the contact on the IN and OUT
leads closes in conjunction with the tones. The
unit continues to broadcast the codes until it is
released by the calling party going on hook or by
someone answering the code call.
When the unit is being used by a PABX, the
ringing voltage on the TO and RO leads from the
PABX station releases the code call unit and
connects the PABX trunk (access) to the PABX
station (answer).
If the unit is being used with 1A2 key telephones,
when the second party goes off hook on the
code call button, the combined voltage drop
across the 10K Ohm resistors in the A leads
releases the code call unit.
The code call unit is designed so that it will finish
broadcasting a code before returning dial tone
and resetting even if answered in the middle of
the code call sequence.
Figure 9 is a simplified schematic illustrating the
main control functions contained in the V-9923B.
TECHNICAL ASSISTANCE
When trouble is reported, verify power is being
supplied to the unit and there are no broken
connections. Be sure the amphenol is secure in
the back of the unit and the cable is terminated
correctly on the cross connect block. Check
voltages for proper polarity on cross connect
block. If a spare unit is available, continue to
troubleshoot by substituting the spare unit for the
suspected defective unit.
Assistance in troubleshooting is available from
the factory. Call (540) 563-2000 and press 1 for
Technical 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
