I have two Sullair air compressors with supervisor controllers. I've been asked to archive all sensor data from them. I found a box sold by Millie Research that converts the supervisor controller protocol to Modbus. Where do I go from here? I know a few languages (C, Java, RPGIV/LE). I'm guessing that C will be the most useful, but I don't even know where to start! Can I download a Modbus header file somewhere and maybe a PDF tutorial? Any help will be greatly appreciated.