PaulS
We ran into issues with using the arduino. As I mentioned we maintain a serial connection to our PC at all times. Randomly we would lose this serial connection, it almost seems like the longer the serial connection was connected, the more likely it was for us to lose it. This was a big problem because our machines are all over the nation, so remotely unplugging the usb or resetting the arduino is nearly impossible ( at least not worth the trouble of developing something just to reset it remotely ). Also, the arduino could not offer multi-threading across the serial connection.
We moved to the parallel port because we can have multi-threading, and we wont have to worry about losing any connection to the device. Its a big deal for us to have the multi-threading because it allows us to listen for interrupts, send commands, and keep a detailed log all at the same time.
I was not meaning to talk bad about the arduino, it is an amazing microprocessor that can offer a friendly introduction into electronics. Or even offer advanced projects for a seasoned engineer. It is a wonderful product and I have my own personal projects using one.