Using with Campbell Scientific Dataloggers
35
When turning the power off to the modem it is advisable to avoid cutting the
power when the modem is online. The program examples in Appendix B
check if the modem is online before turning off the power. You should also
avoid scheduling calls to the logger when it is due to power off. If possible
the AT+CFUN=0 command should also be sent to the modem before cutting
the power to let the modem cleanly deregister from the network and
shutdown its radio modem (also shown in the example in Appendix B). If the
modem is not cleanly shutdown there may be a delay of some minutes before
the network will allow access to the modem again (and in data mode, prevent
modem from establishing a PPP connection).
COM111 based CS-3G modems automatically monitor their
connection to the network and will reset the connection if the
modem believes it has not properly registered on the network
for at least 5 minutes.
11. Fault finding
11.1 General
Before placing the COM111 modem out in the field it is important to check
that it is properly registered the network. To do this, connect it to a power
supply and turn on any power switch, if used, by connecting the power
control line to 5V or 12V. After power has been applied, the small LED in
the case should come on continuously initially. Within 30 seconds the LED
should switch to start to flash briefly every 2 seconds or so indicating that
the unit has registered itself successfully with a GSM network. As a second
check, if the SIM contract allows dialled calls to be made (this is not always
allowed on GPRS/3G only contracts) connect it to a PC and, using a terminal
emulation program, instruct it to dial a valid telephone number, e.g.
ATD01509601091
<
ENTER
>. If the COM111 modem does not cause the
remote phone to ring but instead immediately responds with a result of NO
CARRIER it is likely that:
It has not been registered properly on a GSM network
or
If the COM111 modem has definitely been registered on the
GSM network, check that the registration is for ‘non-transparent
use’. Also check it is enabled for GSM Data (CSD) at 9600 baud
– not just GPRS data. For GSM data connections you need to be
able to connect from analogue landlines – the SIM provider will
normally give you a second phone number to dial it on.
It is not fitted with a SIM, the SIM draw is not in place or the SIM is not
enabled (check with your provider)
or
The SIM is programmed to require a PIN to be entered every time it is
turned on.
This is often the case with newly supplied SIMs.
We
strongly recommend that this feature is disabled; this is best done using a
phone (please refer to your SIM provider for more information).
NOTE
NOTE
