PLC Access® Modem is a remote access device enabling connections to different model Programmable Logic Controllers (PLC) used in various industries. The Dixon PLC Access® Modem enables a remote technician to connect to a machine's PLC through the programming port using an analog phone line. This connection allows transfer of the ladder logic program to, or from, the remote location. Modification, correction, or troubleshooting of the ladder logic can be accomplished remotely, and the revised ladder logic program can be transferred back to the PLC.

The PLC Access® Modem requires only an RS-232 serial port, an analog telephone line, and a +5V dc source (accomplished through a small AC adaptor provided or panel transformer). PLC Access® Modem parameters such as speed and data format are set by the AT commands.