There is no free software for this PLC. However, if you go to "http://www.modicon.com":http://www.modicon.com you should be able to download a demo copy of the ProWORX NxT software. This demo package will give you full programming functionality with the only limitation being the ability to view only the first 25 newtorks in your program.
Try Modicon's ProWorx NxT. This windows package will allow you to configure, program, and trouble-shoot the Modicon "brick" PLC you have. As a matter of fact, if your connection can handle medium to large downloads; check "www.schneiderautomation.com":http://www.schneiderautomation.com where you can get DEMO (almost fully functional) copy of ProWorx NxT 2.2. Hope this helps.
i have been working for 6 years with modicon micro 110 micro 612 00/03 plcs. I can send you a test program that written in ladder language. (to test digital I/O and analog I/O). But do you have MODSOFT editor to download this program. If yes I could send it as soon as possible.