Connecting a Palm Pilot to a Siemens S25 phone.


The Siemens S25 mobile phone is a member of an exclusive group of phones which include a built in modem!. Even better, it has an InfraRed port which allows you to hook your palm pilot directly up to it, cutting out the need for one of those expensive clipon palm modems. True mobile internet with a decent sized screen.


  • Siemens S25 mobile phone.
  • Palm Pilot
  • PalmOS 3.3 or greater.

Palm Setup

In the prerequisites above I have specified a minimum of PalmOS 3.3. However, it is possible to get an IR modem connection up and running using 3.1 (or lesser?) using an IR update from 3Com at http://www.palm.com/support/downloads/irenhanc.html. I only got my S25 after I upgraded to 3.3, so I cannot test the 3.1 installation.

Configuring the palm for IR operation is surprisingly easy. The PalmOS 3.3 update offers several new features, including a new Connection option in the Preferences application.
New options in 3.3

From within this option, you can configure a number of different connections to IR or serial hardware. I have created a new connection called "IR to S25". The connection method is IrCOMM to Modem, which routes the data over the IR port into the modem on the S25. Within the details tab I have set the baud rate at 9600bps. I believe this is the speed from the pilot to the phone, a bit like the speed from the serial port to the modem on a PC. In that instance you usually put the speed at 4x the rate (115200bps for a 28k/33k modem) as the PC serial port can cope with this.
an IRCOMM connection

Once that's done, all that is needed is to setup a dialup profile for it in Prefs\Network. Remember to set the Connection to the one you created above then click Connect.
ISP setup

The Service Connection Progress dialog box will appear, remember that pressing the down button on the palm, you can see a better diagnostics line indicating what part of the process it is up to.

Unfortunatly, thats about as far as I go. I have managed to get this to work on a handful of occasions, the rest of the time the S25 hangs up after (exactly) 30 seconds. As far as I'm aware its not a idle timeout, the Palm still shows "Signing on {Negotiating in the diagnostics line}. The palm log (shortcut, L, or Options/View Log on the Preferences dialog) would show a number of  LCP requests, acknowledgements, and rejections before just eventually giving up. I keep trying it every so often, but its a costly effort due to the tarriff I'm on. It could be a palm issue, but it looks awfully like its the remote end giving up after 30 seconds cos its not happy with the client (my palm). The next item I'm going to test is turning of LCP requests on the palm, if this can be done.

Addenum: I have had successful reports of people being able to do this with S25's (and other Siemens phones), so its likely just Vodafone being picky.


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