Sierra Wireless DART 200 CDPD Modem manual UDP server setup options

DART 200 CDPD Modem User’s Guide 5 DART Supported Protocols

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NOTE:

When the listening port is changed it is not active until the server is stopped and restarted, or the modem is reset with an AT-R or a power cycle.

∙Receive locking capability to allow the DART 200 to function as a UDP server by holding off incoming messages until the preceding message is answered

∙Eliminates the need for the M-ES and Host modems to use a common port number. The server uses the source address contained in the incoming packet as the destination address for outgoing packet

∙Backward compatibility with the basic UDP function in earlier DART modems by an S-Register setting. When there are DART modems involved in the UDP application that use non-server software, activate this feature

These added features make the DART UDP server compatible with industry standard client-server models where the client originates communications and the server waits for incoming communications requests.

UDP server setup options

In addition to the new options discussed here, the same setup options used with basic UDP, as described on p. 5-4, also must be considered before proceeding to step 1.

1.Set the defining setup parameter for the UDP server function ( *An - select server type) to 2 with an AT*A2 command. Selecting this option enables the UDP server function. The default value for this parameter is *A0 (no server active). This is appropriate if the MAS application always operates in client mode; always originates the connection request with an ATDP command.

2.With the UDP server option enabled, choose the method used to answer incoming calls. The preferred method is to set S-Register 0 = 1 with an ATS0=1 command, which puts the modem into permanent auto answer mode. The alternative is for the MAS to use the answer command, ATA. This command could be used in response to a RING message, or in anticipation of an incoming call. However, in the latter case, since the command is only active for 20 seconds it has to be used in a programming loop to receive a call.

3.(Optional) Select the port to listen for incoming messages on. For basic UDP the listening port is fixed at 2100. However, with the UDP server the listening port can be set using the *L command. The command format is AT*Ln where n is the desired listening port; a decimal number in the range of 1025 to 4999 for compliance with industry standards.

4.If the listening port is changed, save it with an AT&W. The default value for the listening port is still 2100 for backward compatibility with basic UDP.

The remaining setup options for the UDP server are controlled by the contents of S-Register 82, including:

∙Friends Only mode

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