WinWedge does not support the Modbus protocol. Modbus is a high level protocol that defines the communications process between (usually) industrial controllers. Modbus uses ASCII data however it also uses check digits, timeouts and special framing characters that make the protocol a little more difficult to work with than what the Wedge can handle on its own. The developers do have customers that have been successful using the Wedge to communicate with Modbus devices however it required that they write code in their application to implement the Modbus protocol. For example, you could write macros in Excel that would implement the Modbus protocol and use the Software Wedge to do the raw serial I/O. The developers only recommend this as a solution for someone that is both a programmer and also knows the Modbus protocol extremely well.