Sierra Wireless DART 200 CDPD Modem - Manual (Page 116)

DART 200 CDPD Modem User’s Guide 8 Application Programming
Sierra Wireless, Inc. 8-22
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).
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.
? ?
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.
? ?
NOTE:
Autobaud is active in
command only.