Communication among machines in a production system is important as it provides synchronism and fluency in the manufacturing processes. Set out below is the development of the TCP/IP communication for a pallet transport line system intended to improve the working of the plant. This was carried out starting with the comprehension of the line and the machines in interaction, understanding the programs previously developed and setting up the TCP/IP functions in ISaGRAF. A human machine interface in Movicon was employed to supervise and test the line. The communication via TCP/IP was established, the protocol among servers and machines was correctly implemented and it was possible to supervise the whole process and carry out a real test using the human machine interface.