This article describes the development of a methodology applied to the classification of errors industrial communication network (Modbus TCP / IP), through a pattern recognition method is described.The tests were conducted with the programming of a PLC TWIDO TWDLCAE40DRF, and was subjected to disturbances or faults generated on the network.Data were acquired and monitored by the ModScan32 tool and were subsequently processed through the Principal Component Analysis (PCA), obtaining a success rate in discriminating 100%.In this study was possible to classify easily and quickly some factors or errors generated in a Modbus communication.