Using with Campbell Scientific Dataloggers
41
SMS messages or, if the modem is online and with a fixed IP
address, by opening a telnet session with the modem and issuing
AT commands to the modem by that interface. Please contact
Campbell Scientific for more details of these advanced options if
needed.
11.6 A base station fails to get a response from the logger
with a modem in GSM dial-up mode
Check the following points:
Is the COM111 modem configured to ignore hardware handshaking? –
It will be if setup with the Mobile Data Assistant.
Was the COM111 modem configured with the “Modem Mode” setting
set to 2G. This is the only mode that will allow GSM dial-up mode as
this mode is not supported for 3G connections.
Have you ensured that your base station modem setup includes
commands to switch off flow control from the base station?
Are you powering the COM111 modem on and off periodically?
If so, the data logger program which is controlling the power of the
COM111 modem is either wrong, or is not running (perhaps due to a
low battery voltage).
The number you are dialling - is the voice number for the SIM rather
than the data number - if you get a "dead line" when the COM111
modem is on or an "answerphone" service when it is turned off this is
almost certainly the problem.
If you manually dial the number with a phone and hear a buzzing noise
rather than modem negotiation tones (beep and whistles) the SIM is
configured to accept incoming digital (UDI) calls only - contact the SIM
supplier.
