Standard Horizon GM29 manual Network registration Call barring Call transfer

2.GM29 MODEM

•Network registration

•Call barring

•Call transfer

2.4.7Serial Communication

The GM29 enables an end-to-end communication path to be established between the external telemetry/telematics application and a remote terminal or host, via the GSM network. Once a path has been set up, voice or data communication can take place. Serial data with flow control according to the RS232 signalling protocol operates between the modem and the external application.

Control of the GM29 is by the external application, via the RS232 serial interface, using a set of AT commands. The GM29 supports the full set of AT commands according to GSM 07.05 and GSM 07.07. It also supports an extended set of Ericsson proprietary AT commands to add extra functionality.

AT commands are used to operate the modem and have a broad range of functions including:

•configuring general parameters of the GM29;

•setting up and controlling communications to and from the GSM network;

•configuring the modem to communicate across the RS232 serial interface;

•and obtaining GSM network status information.

For more detail on the AT commands supported by the GM29 see “Alphabetical Listing of AT Commands”, page 261.

2.4.8 Interfacing with the GM29

The GM29 uses the following industry standard connectors to interface with the external application and the GSM network;

•RJ11 (plug-in power supply connector)

•RJ9 (handset audio connector)

•Integral SIM card reader

•FME male (antenna connector)

•Sub-D socket, 9 pin (RS232 serial port)

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LZT 123 7361 R1A