Sierra Wireless MP215 manual Host Interface, General Description

9. Host Interface

9.1. General Description

The MP215 supports both a SLIP and AT-command interface.

For a complete list of AT commands, the user should reference the Sierra Wireless Modem User Guide and the AT-Command Extension R2.5.2 reference guide, which describe the AT and extended AT commands that the MP200 family of products support.

Note however that the MP215 is not fully backward compatible with other members of the MP200 family and the differences in AT commands supported and responses to them are discussed here.

The fact that the MP215 has both CDPD and CS-CDPD modes, coupled with the nature of running CDPD over a circuit-switched cellular connection, requires that the response to some commands will differ depending on the mode the modem is in.

Another major behavioral difference the MP215 has over other MP200-family products is that the modem will not be on-line connected if the host DTE port is in the AT-command idle state, i.e. waiting for an AT command. An idle host DTE port means that that the modem is waiting for another AT command to be entered, and is not currently executing a command.

All normal operations are performed as needed only when the host DTE port is in a SLIP session, or during the execution of an AT command. (Being in an active SLIP session can be thought of as executing the ATD or ATO command, which runs until the SLIP session is terminated).

This means that if the host DTE port is idle, the MP215 will:

∙Not answer an incoming AMPS call

∙Not originate an outgoing AMPS call

∙Not monitor network status nor switch sub-modes between AMPS and CDPD.

∙Not attempt to register (or re-register on timer expiry)

∙Maintain its current registration status (e.g., registered/suspended).

PN 2110036 Revision 1.0 05/11/99 9-1