We would suggest you look at one of the T100MD+ PLC at the page:
http://www.tri-plc.com/t100md.htmThese PLCs have the power, flexibillity and expandability that make them suitable for many different control applications. The main difference betwee the 3 models of T100MD+ PLCs are the number of digital I/Os and analog I/os that are available each model.
These PLC can be programmed using our "Ladder+BASIC" programming language which combines the best features of ladder logic and BASIC language. You can connect them RS232 or RS485 devices, MODBUS RTU, modem, wireless modem, ethernet adapter, LCD display etc etc. Many users find the language powerful and easy to learn.
You can buy a T100MD+ starter kit (the one for T100MD888+ is only $259) which comprises the PLC, programming software, programming cable and all the user manuals. Add your own 12 to 24VDC power supply and a Windows PC and you are set to go and explore the wonders that the T100MD+ can accomplish