Sierra Wireless DART 200 CDPD Modem manual Channel acquisition restrictions, Baud considerations

DART 200 CDPD Modem User’s Guide 8 Application Programming

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NOTE:

If a \N0 command is entered, which frequently happens when a new user inadvertently enters an illegal AT\N? command, it forces home only mode; a combination of \J1 and \N0. This prevents channel acquisition unless a WASI or LASI is entered or \J is reset to \J0.

Channel acquisition restrictions

This feature of the modem limits the RF channels available for modem use. It is controlled by the AT\Jn command; one of the modem’s profile parameters. If activated, this feature limits the modem to using channels where a channel identifier, such as a service provider ID (SPI), service provider network ID (SPNI), wide area service ID (WASI), local service area ID (LSAI), or various combinations of these, matches values previously stored in the DART 200 with AT^H (SPI), AT^I (SPNI) and/or AT^L (WASI or LSAI) commands. The options available vary depending on the CDPD version used. Refer to the \J command in Appendix F, DART AT Commands, for more information.

The values for SPI, SPNI, and WASI or LSAI stored by the end-user can be viewed by AT^H?, AT^I?, and AT^L? commands. View the values for these items being broadcast by the network with the AT&V+ command. The WASI or LSAI is found in S-Register 107, the SPNI in S-Register 108, and the SPI in S-Register 114 (CDPD 1.1 mode only).

Restrict channel acquisition by making one or more entries for SPI, SPNI, and WASI and then activating the feature with an appropriate \Jn setting. When this feature is activated, the DART 200 cannot acquire a channel unless the identifier specified by the \Jn choice matches those being broadcast by the carrier; usually, only a single restriction is applied (\J1, \J2, or \J3).

Multiple item restrictions (\J4 through \J7) let the end-user be more creative for special applications. Multiple entries of a specific type (SPI, SPNI, or WASI) are logically OR’d, and entries of different types are logically AND’d. For example, if two SPNIs are entered, the channel is acquired if either SPNI was found. If a SPNI and a WASI are entered the channel is acquired only if both were found.

The default value for \J is no channel acquisition restrictions (0).

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NOTE:

Autobaud is active in command only.

Baud considerations

The DART 200’s default communications port settings are 9600 baud, with 8 data bits, no parity, and 1 stop bit with autobaud active. The autobaud feature allows the DART 200 to sense speed and data format of attached devices and adjust accordingly. The DART 200 does this by keying on the leading A (upper- or lowercase) of an AT command; other leading characters do not trigger the autobaud feature. Autobaud is active in command mode only.

Sierra Wireless, Inc. 8-22