Sierra Wireless DART 300 User Manual

Feature Reference 

 

DART 300 Modem 

 

Page 60 

 

2110212 Rev 1.0 

The DART 300 LED indicator reflects the modem’s registration status.  The flash patterns are as 
follows: 
•  On steady (not flashing) indicates power is on but no CDPD channel is visible.  The modem is 

typically scanning for a channel at this time. 
When first powered on, the LED will appear dim during the modem’s internal initialization.  
After the initialization is complete, the LED will appear at normal brightness. 

•  Flashes on once per second with a 10% duty cycle (100ms on : 900ms off) if the modem has 

acquired a CDPD channel but is not yet registered. 

•  Flashes on twice per second with a 10% duty cycle (100ms on : 100ms off : 100ms on : 

700ms off) if modem is registered on a CDPD channel. 

•  Off indicates the modem is in CDPD sleep mode or has no power. 

Prior to finding a channel, many query items will return 0.  Once locked onto a CDPD channel, the 
modem can provide several pieces of information about the connection.  Additional information is 
available regarding the registration of the modem. 

There are two primary monitors of signal strength. 

A “percentage” value can be read from register +WS50 (Normalized Signal Strength).  It reports a 
value from 0 to 100 where 0 is imperceptible and 100 is full signal. 

The Receive Signal Strength Indication (RSSI) is more informative.  It is read with the RSSI and 
Channel State command (+WPRSSI).  It reports: 

•  Signal strength in dBm (-113 to -30), 
•  State of the channel (1 - Scanning, 3 - Acquired), 

•  Registration Status (0 no, 1 yes) 
•  Channel number (0 if scanning) 

Note that the registration status reported here is that of the Active NEI Index (+WS197) which 
may point to a NEI other than the one that is in fact registered.  Consult register +WS56 to check 
the registration status of the modem. 

The channel number is available from register +WS200.  A value of 0 indicates the modem has 
not acquired a channel. 

+WPRSSI also reports the current channel as the last of the four items returned. 

When the modem has locked onto a channel (whether registered or not) the Service Provider 
Network Identifier (SPNI) for that channel can be read with the command +WCID. 

Although not important in most circumstances, the number of the current CDPD base station is 
available from register +WS210.  This is available when the modem has channel lock and may 
not be registered.