So our company is using Panasonic Toughbooks CF-52 and 53s with RS 232 serial ports. Our techs use them to do work on Airplanes and they must use a Serial port to plug directly into the planes. The problem with a USB to rs 232 cable is that they are unreliable and there are many fake cables on the market. We would prefer to just find another newer model that has the serial port on it. It would be best if they were bulky and hard to destroy as some of our tech abuse them. So far I haven't found any current models with what we need. Any advice would be helpful.