S611 Soft Starter MN03902011E—May 2012 www.eaton.com 65Appendix F—Network Communications (Modbus)Modbus with IO FunctionalityModbus General SpecificationsNote Line polarization will reduce maximum number of devices by four.Parameter ValueMode Slave mode onlyByte characteristics RTU: 8 bit, even parity, 1 stop bitASCII: 7 bit, even parity, 1 stop bitSlave response to master 10 ms plus the time it takes to transmit response (when applicable)Commands supported 0x01 Read Coils0x02 Read Discrete Inputs0x03 Read Holding Registers0x04 Read Input Register0x05 Write Single Coil0x06 Write Single Register0x0F Write Multiple Coils (15)0x10 Write Multiple Registers (16)0x17 Read/Write Multiple Registers (23)0x2B/0x0E Read Device Identification Get Device Identity (43/14)Protocol supported ASCII or RTUElectrical signaling RS-485 (ANSI/TIA/EIA-485), two-wireChecksum CRC 16 bit 0x8005 (or CRC-CCITT 0x1021)Maximum data signaling error accepted 2% in reception, 1% in transmissionMaximum number of devices 32 (1 unit load per RS-485)LED indication Device busyMaximum cable length Dependent on baud rate, cable characteristics (gauge, capacitance, or impedance), number of loads, 4000 ftmaximum theoretical. Reference Modbus-IDA over Serial Line Specification and Implementation Guide andEIA-485 for detailsMaximum number of writes to non-volatile memory UnlimitedConnector style Screw terminalNetwork topology Two-wire Modbus, daisy-chain and/or repeaterLine polarization Not required. Reference Modbus over Serial Line Specification and Implementation Guide and EIA-485 formore informationwww.comoso.com
