Sierra Wireless DART 300 User Manual

References 

 

DART 300 Modem 

 

Page 116 

 

2110212 Rev 1.0 

Some registers and commands share dependencies and inter-relationships that need to be well 
understood to avoid unexpected behaviour. 
•  +WS176 specifies the Network Entity Identifier (NEI) index to auto-register when CDPD 

mode is invoked.  +WS197 specifies the NEI index to target for the configuration (+WPNEI) 
and register/de-register (+WPREG/+WPDEREG) commands.  There are subtle interactions 
when +WS176 != +WS197. 

•  Changing +WS197 by itself does not change which NEI is registered with the network. 

•  Changing +WS176 by itself does de-register the current NEI and attempt to register the new 

one if allowed by +WS173 (Registration Mode).  This does not change +WS197, so 
+WPNEI? can report a different NEI than that which is registered and +WPRSSI can report 
a registration status other than what might be expected.  Use +WPCURNEI to report the 
registered NEI.  Use +WS56 to determine registration status. 

•  +WPREG/+WPDEREG do register/de-register the NEI indexed by +WS197, making it the 

current NEI, so that +WS176 becomes the same as +WS197, and +WS176 is stored in 
NOVRAM. 

There are interactions between +WS176 (Auto-register Index), +WS179 (Registration Wait 
Status), ATH, ATD and the signals Data Terminal Ready (DTR) and Data Carrier Detect (DCD). 

•  If +WS179 is non-zero, ATD waits for registration success before connecting. 
•  If +WS173 is zero, then ATD in effect issues a +WPREG command for the NEI indexed by 

+WS197, also setting +WS176=+WS197. 

•  ATH1 will always de-register the current NEI and will disable auto-registration until 

+WS173 is re-written with 1 or the modem is reset.  +WS173 will continue to report that it 
is set for auto-registration (equal to 1) even though the modem has stopped trying to register. 

•  ATH0 de-registers the current NEI only if +WS173 (Registration Mode) is zero (Manual). 
•  DCD is dropped on ATH0, ATH1, and on DTR on-to-off transition if &D2 is set. 

This table provides a numerical list of the result codes possible. 

OK 

Command executed without error. 

CONNECT 

Client Sessions – In SLIP and UDP this means a session is open and 
the modem is in data state, but does not necessarily verify that the 
modem is registered on the network.  In TCP it indicates the session is 
open and the destination is logically connected. 

Server Sessions – The modem has opened the session and gone into 
data state.  The CONNECT message will be appended by the IP 
address of the caller. 

RING 

A connection to an accepted IP is requested. 

NO CARRIER 

Carrier signal lost or not detected. 

ERROR 

Illegal command.  Error in command line.  Command line exceeds 
buffer size.  NVRAM failure. 

CONNECT 1200 

Connected at 1200 bps. 

PAD ERROR 

An error has occurred in the packet service stack.  The modem must be 
reset. 

NO ANSWER 

TCP service failed to complete the connection handshake.