Feature Reference | DART 300 Modem |
7.3.Monitoring the Network Connection
7.3.1.LED Indicator
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.
7.3.2.Radio Signal Monitors
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.
7.3.2.1.Signal Strength
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
•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.
7.3.2.2.Current Channel
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.
7.3.2.3.SPNI of the Connected Carrier
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.
7.3.2.4.Cell Number
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.
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