Service and troubleshooting
8.18 EST3 Installation and Service Manual
of rapid chirps as data is transmitted from the ACDB or KDC
program.
Note: Remove the amplifier when you finish troubleshooting.
Do not install the amplifier permanently.
Common causes of problems
Evaluation of visual and audible indications will usually serve to
isolate the source of trouble. Before attempting to replace the
3-MODCOM module, the following causes of problems should
be investigated:
• The 3-MODCOM module is not properly seated on the rail
connectors, or one or more connector pins have been bent
away from the associated sockets
• A modular telephone plug is not connected to the appropriate
line 1 or line 2 jack, or is not fully seated, or is not connected
at the telephone block
• The 3-MODCOM has been configured with incorrect CMS
telephone numbers
• The telephone line is faulty
If the module and telephone line are okay, check the CMS
telephone number by dialing it using a standard telephone
plugged directly into the RJ-31X jack. (The jack will
accommodate a standard modular phone plug.)
You should hear a dial tone when going off-hook, lose the dial
tone after dialing the first digit, hear the receiver ringing, hear
the CMS receiver go off-hook and send a handshake tone.
Typical problems dialing the CMS involve missing or incorrect
area codes, the need to dial 1 for long distance, and missing line
access codes (example: dialing 9 for an outside line).
If the receiver answers, check that it is sending out the correct
handshake. For SIA P2 (3/1 pulse), SIA P3 (4/2 pulse), and SIA
DCS the receiver should send a single tone of 0.5 to 1.0 seconds
in duration. For Contact ID, the handshake signal consists of two
short tones of different frequency. For TAP there should be a
modem-type exchange of handshake messages.
If the receiver sends the correct handshake and the 3-MODCOM
transmits data but the receiver does not send an
acknowledgement, check that the receiver is compatible with the
desired protocol. (SIA DCS, P2, and P3 standards are available
from the Security Industry Association). Typical problems
involve an incompatible format or data message.
If the handshake and acknowledge signals are audible, check that
the correct account number was configured in the 3-MODCOM
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