GSM settings
Operator lists
FMB920 can work in different modes (use different settings) according to the operator list defined. Operator list is used for Data Acquisition mode switching (see Data acquisition settings section for more details). Modes are changed based on the GSM operator FMB920 is connected to.
Configuring device roaming and blacklist operators is recommended to optimize device performance by mitigating additional latency.
If the roaming operator list is left empty, FMB920 will automatically detect the home operator. If the home operator is written to the roaming operator list, it will still be detected as a home operator. Any operator not in the roaming operator list (except the home operator) will be recognized as an unknown operator and FMB920 will work in Unknown mode (make sure it is configured to allow data sending – GPRS context is enabled).
If the user wants FMB920 to not connect and work with a particular operator it has to be written to Operator Blacklist. Up to 50 operators may be entered into this list.
The Operator search procedure is initiated every 15 minutes. During the search, FMB920 tries to connect to the operator providing the strongest signal. It will prioritize operators that are specified in the operator list. If no operators from the operator list are available, the device will try to connect to an operator from the blacklist. If the device connects to an operator from the blacklist, the best operator search procedure is initiated instantly. During the time when the device is connected to a blacklisted operator, no GPRS connection would be initiated and no data would be sent via GPRS. However, the ability to send SMS commands to the device would remain. If no suitable operator is found on both lists, the device will try to connect to a remaining available operator with the strongest signal.