PLCs Interfacing to a PC

I want to collect some information of speed of a running machine through a sensor to a PLC and record it in a PC.

The above record can be to a Microsoft XL sheet or a VB6 program.

I am planning to use a Mitsubishi FX1N series PLC. Please let me know how this can be achieved. I prefer Mitsubishi PLCs only.

Expecting a detailed reply.

Expectations and Communications !?!?!?!?!?!?

You can connect to FX series PLC easily through serial port.
To communicate with the PLC you can have few options such as
using MX-Components library for example (or you can write your
own if you want to, I've seen one for FX in download section
of www.MrPLC.com).
If all you want is to read value from PLC, you should be able
to setup PLC to send you an ASCII message with whatever results
you want to record. It is very simple to read COM port using VB
extract value and place it in a record.

hope this helps