P12x/EN T/Eb6 - Schneider - error

P12x/EN CT/Eb6MODBUS DatabasePage 4CommunicationsMiCOM P120/P121/P122/P1232. MODBUS PROTOCOLMiCOM P120, P121, P122 and P123 relays can communicate by a RS 485 link behind theunit following the MODBUS RTU protocol.2.1 Technical characteristics of the MODBUS connection2.1.1 Parameters of the MODBUS connectionThe different parameters of the MODBUS connection are as follows:−−Isolated two-point RS485 connection (2kV 50Hz),MODBUS line protocol in RTU modeCommunication speed can be configured by an operator dialog in the front panel of the relay:Baud rate (dec)30060012002400480096001920038400Transmission mode of the configured characters by operator dialog.Mode1 start / 8 bits / 1 stop: total 10 bits1 start / 8 bits / even parity / 1 stop: total 11 bits1 start / 8 bits / odd parity / 1 stop: total 11 bits1 start / 8 bits / 2 stop: total 11 bits2.1.2 Synchronisation of exchanges messagesAll character received after a silence on the line with more or equal to a transmission time of3 characters is considered as a firm start.2.1.3 Message validity checkThe frame validity is working with a cyclical redundancy code CRC with 16 bits.The generator polynomial is:1 + x² + x 15 + x 16 = 1010 0000 0000 0001 binary = A001h2.1.4 Address of the MiCOM relaysThe address of the MiCOM relay on a same MODBUS network is situated between 1 and255. The address 0 is reserved for the broadcast messages