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APPENDIX 1
LED Indications (continued)
The Communication LEDs
are Red and Yellow. See Fig 1 & 2.
PSTN Line Failure Indications:
The red PSTN LED will flash to indicate the type of line or communication
failure. If more than one type of failure is detected, the lowest number will be
displayed.
Regular slow
on-off flashing
The NVM is blank or it is not programmed correctly.
1 flash
PSTN telephone line DC voltage is very low or absent.
2 flashes
Another phone (or fax, modem etc.) on the same PSTN line is off-
hook and may inhibit the DualCom from making a telephone call.
3 flashes
Incoming ringing is detected and this may inhibit the DualCom
from making a telephone call.
4 flashes
The regular dial-tone test has failed indicating that there may be
a PSTN line fault and this can inhibit DualCom from making a tel-
ephone call. Check that the Service Provider is still providing a
service (paid the bill?).
5 flashes
When the DualCom tried to make a telephone call, another phone
(or fax, modem etc.) on the same PSTN line was off-hook and
Dualcom could not make its call.
6 flashes
When the DualCom tried to make a telephone call, incoming ring-
ing was detected, and the DualCom could not make its call.
7 flashes
When the DualCom tried to make a telephone call it failed to hear
a dial-tone and could not make its call. See Callminder section.
