4. MODES OF OPERATION
The standard mode for operation of the GSM Modem Unit is for the modem to be powered and
on ‘standby’ to receive a call 24 hours a day.
There are some ‘jumpers’ on the electronics board which can change this mode of operation,
normally they will not need to be changed but it would be good to be aware of them.
See Figure 1 and Figure 3 showing the layout of the inside of the GSM Modem Unit. Just above
the red LED light which indicates whether the modem is active, there are a pair of jumpers marked
L12 and L13.
If there is a small black connector across the two pins of L13, then the system will operate in
standard mode and will power the modem 24 hours a day.
If there is a small black connector across the two pins of L12, then the system will never power up
the modem, this is a permanently OFF position, used for servicing etc.
If there is no connector across either L12 or L13 then the ‘telephone pager activator’ function is in
operation. The buttons in the centre of the electronics board, blue to Start and red to Cancel, will
activate the modem for the time period set by the ‘Pager ‘on’ / Test period link settings’ – see
Figure 1, Figure 3 and also the GSM TC35iT Modem Unit manual.
The ‘telephone pager activator’ option is only available in the UK at the moment. If you are able
to locally source a standard numeric telephone pager, which is powered by a single 1.5V battery,
then it may be possible to use this option in your own country. Please contact Skye for details.
When the red LED ‘modem active’ is lit, then power is being applied to the TC35iT modem and the
green LED on the modem itself should flash slowly, about 1 flash per second. When a call is being
connected to the modem, this green LED will flash much faster. It will return to the slow flash as
soon as the call is finished.
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TC35iT Installation & Programming Manual
