MiCOM P921/P922/P923 - Schneider - error

Connection DiagramsP92x/EN CO/F22MiCOM P921/P922/P923 Page 9/102.2 RS485 rear port2.2.1 DescriptionThe rear RS485 interface is isolated and is suitable for permanent connectionwhichever protocol is selected. The advantage of this type of connection is that up to31 relays can be ‘daisy chained’ together using a simple twisted pair electricalconnection.2.2.2 Connection1357911131517192123252724681012141618202224262829313335373941434547495153553032343638404244464850525456CommunicationconnectionsRear terminalsP0180ENaFIGURE 7: RS485 CONNECTIONThe total communication cable from the master unit to the farthest slave device is aspur, and no branches may be made from this spur. The maximum cable length is1000m and the maximum number of devices per spur is 32.The transmission wires should be terminated using a 150 Ω resistor at both extremeends of the cable. To do this, connect the terminals 30 and 32 together.Polarity is not necessary for the 2 twisted wires.WARNING:TERMINALS F33 AND F34 ARE USED FOR THE POWER SUPPLY. DONOT CONNECT THE VOLTAGE POWER SUPPLY TO TERMINALS F31AND F32.2.2.3 Convertors2.2.3.1 Protocol convertor: RS232 -> K-BusKITZ 101,102 and 201 can be used.Configuration is: 19200 bauds, 11 bits, full duplex.2.2.3.2 RS232 / RS485 converterThe following RS232/RS485 converters have been tested by AREVA P&C:RS_CONV1: convertor suitable for a short length and forup to 4 connected relaysRS_CONV32 : industrial convertor, suitable for up to 31connected relays.