Indunium 2i User Guide
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4.2
GSM CSD Connection (Only Available under Normal Mode)
4.2.1
Overview
A Circuit-Switched Data Connection makes the wireless modem work in a manner similar to a regular
analog modem.
CSD (Circuit Switched Data) is the original form of data transmission developed for GSM systems. By using
a single radio time slot, CSD is able to deliver 9.6 to 14.4 kbit/s data transmission to both the GSM Network
and PSTN Switching Subsystem through direct calls. Most of the time, it is initiated by standard AT
commands. Using the modem to access remote devices by CSD is often more convenient than installing
cables and data lines. Data collection and monitoring will be more flexible since CSD can be used for
applications that are hard to wire or hard to access.
Note: Ensure that your SIM card has the CSD Service activated. For most regions, you must apply to your
mobile service provider to receive this service.
4.2.2
Establishing a CSD Connection
1.
Enable CSD at Basic Tab under Normal Mode;
2.
Start Indunium-R Modem Configurator and click the Debug tab under Config Mode, with the current
communication parameters (default: 115200 bps, 8 for Data bits, None for Parity, 1 for Stop bits, and
None for flow control).
3.
Type ATD <
phone number
> and click Send to establish a CSD connection. (e.g. ATD 123456, in
which 123456 is the phone number.)
4.
After remote side answering the CSD call, then the CSD connection has been established successfully,
and you can switch to data mode to proceed with data communication.