Is there a simple telnet server code for the FXT009/FXT02?


It is becoming very aware that we purchased a product that does 10 million times more than what we need it to do, and do not have the time or programming experience to turn it into what we do need.

What we need is for the device to accept a telnet session, and allow the usage of the AT commands to send SMS messages, and return the OK or ERROR result. If all else fails, I know I can get a Serial to Ethernet adapter or a USB to Ethernet adapter, and get the communications working to the server. But I would hate to spend more money if it is unnecessary.

Is there any sample code that comes very close to this functionality? I can program, but it is not my primary job or field of expertize, so while I can take existing code and tweak it, starting from scratch is currently beyond me.

Thank you in advance for any assistance and guidance.



You can go through the “TCP_server” sample code provided with SDK(and provided as part of WIP or internet library).

TCP client can connect to the the telnet server using the same approach.

Please follow the following link for some reference :



You’ll need a Public IP address for that…


Why would we need a public address, since both the FXT009 and the server that would be sending the SMS messages are both on the internal network. The only reason the server doesn’t connect to the FXT009 via serial cable is that the server is virtual, running under VMware.


Thank you! I went through that, but as it states, I would still need to program the ability to take the telnet input, parse it to the AT commands, and then process it from there. That is just too much time for a simple SMS modem to attach to a virtual machine.

So I have ordered a Serial to Ethernet adaptor, and it will install a virtual com port on the server, so every thing talks properly.

Thank you again for the help though!


Sorry - I thought you were talking about having the Telnet session over GPRS.

Does the VM have an internet connection?

If it does, why bother with a modem - why not use an SMS gateway :question:


That would be cost. You can get unlimited SMS deals with SIM card for relatively low cost. SMS gateways tend to charge per SMS which mounts up over time.


But not zero cost - so there is still a “price per SMS”.

And most of these deals, if you read the terms, would prohibit “automated” use…

You also have to consider the cost of the modem, providing the connection to the modem, having to site the modem somewhere with decent signal, etc,…

Sending an SMS through a modem is a very slow process - not suitable for high-volume…

Server programmers generally don’t seem to be too keen on dealing with RS232 connections, AT Commands, etc,…
(not being a “server” programmer, I wouldn’t know - but I have heard that it’s “not nice”)

Indeed - but they do tend to be cheaper than the per-SMS changes of a phone contract.


The only server talking to the SMS modem is the network monitoring server. It will send an email alert, and a SMS alert on outage. The company was looking for a secondary/out of band pathway in case the outage was the internet connection. So using a SMS gateway via the internet would defeat the purpose of the SMS modem.

We are not looking at high volume - perhaps 10 - 30 messages a month. AT&T has a special SMS only contact just for the Sierra Wireless device, and at the volume level that we signed up for (400 messages a month), we are paying $9 USD for the access.

The network monitoring software already had the ability to talk to a SMS modem device, all you have to put in the alert screen is the com port to access, the number you are sending the SMS to, and it handled the rest. So there was no custom interface on the server being created or configured.

When I first began looking into this, all I was finding in my searches was SMS modems that started at $600 USD and went up. Finding the Sierra Wireless kit for $269 USD seemed perfect. Had originally planned on purchasing a Serial to Ethernet adapter ($99 USD), so it was a very inexpensive way to provide secondary alerting pathing. When I found out that the FXT009 had a ethernet card, thought that was even better, no need for a secondary device.

In any case, the system is up and working using the FXT009 and a Serial to Ethernet adapter, a virtual com port on the network monitoring server, and we have the secondary alerting pathway the executives wanted.

Thank you all for your assistance and time!


Right. That explains it.


Hi James,

I recommend you also look at the Raven XE . We have numerous customers who use this product for ADSL backup, meaning that not only would it send and SMS if required (to notify ADSL outage), but it can also ensure business continuity over 3G if required.

And pretty easy to integrate, as this is a product who natively supports Ethernet connectivity as well.