APPENDIX 1
LED Indications (continued)
The Communication LEDs
are Red and Yellow. See Fig 1 & 2.
Communication indications:
LED Off
PSTN or Radio path not activated.
LED On solid.
Path activated or dialling numbers.
LED On + short off-blinks.
Dialling completed, waiting for ‘handshake’
(3 off-blinks per sec)
from receiving equipment.
LED rapid flash.
Handshake received, sending data to
(On & Off 12 times per sec)
receiving equipment.
LED 15 medium flashes.
Communications successful. Data
(On & Off 5 times per sec)
received correctly at receiving equipment.
GSM Path Failure Indications:
The yellow Radio LED will flash to indicate the type of failure. If more than one
type of failure is detected, only one will be displayed.
1 flash
SIM Card OK, GSM Radio OK, connection fault. Check aerial,
signal strength, and that the Service Provider is still providing a
service (paid the bill?).
2 flashes
No response from GSM Radio module, check connections.
3 flashes
There is no SIM Card fitted, or it is not fitted correctly.
4 flashes
The SIM Card is locked. The PUK1 code is required to unlock it.
5 flashes
The SIM Card PIN number is missing or wrong.
6 flashes
The SIM Card SMS Message Centre telephone number is invalid.
7 flashes
GSM Radio module fault detected by internal tests, replace unit.
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