Hi, Here is a little Ethernet/IP library (TuxEIP) that can help you to read / write in Allen-Bradley PLC (Micrologix, SLC500, PLC5, ControlLogix ....). This library is written in C and work fine under Linux. You can find also a sample utility (ReadTag) for use it. This project is free and under GPL licensing. http://www.tuxplc.net Feedback are welcome to help us improving this project.