Echelon i.LON 10 Ethernet Adapter - Manual (Page 39)

Using GSM/GPRS Modems with the i.LON 10 Ethernet Adapter
In order for a GSM or GPRS modem to communicate with the i.LON 10, it must
support all of the following signals: Tx, Rx, GND, RTS, CTS, DSR, DTR and CD.
Check with your service provider to confirm that the modem you want to use
supports these signals.
GSM/GPRS Service Providers Tested with the i.LON 10
Ethernet Adapter
The following table lists the GSM/GPRS service providers that have been tested
with the i.LON 10 Ethernet Adapter and recommended init strings for each
provider:
Service
Provider
Uplink/
Downlink
Init String
T-Mobile Both E0Q0V1S0=0&C1M1+CGDCONT=1,
"IP","internet2.voicestream.com"
AT&T Uplink
only
E0Q0V1S0=0&C1M1+CGDCONT=1,"IP","proxy"
In order to establish a downlink connection over GSM, a service must support
CSD (Circuit Switched Data). This service is supported by T-Mobile. If you want
to establish downlink connections using services that do not support CSD (such
as AT&T) you have the following options:
• Keep the GSM/GPRS connection open all the time and inform the LNS
Server of the IP address.
• Use the shoulder-tap method (see Configuring the i.LON 10 Ethernet Adapter
for Shoulder Tap, earlier in this Chapter) to have the i.LON 10 establish an
uplink connection, then ensure that the LNS application sends the downlink
messages when the connection is established.
i.LON 10 Ethernet Adapter User’s Guide 4-15