6 -98MEMOBUS communications can perform the following operations regardless of the settings in b1-01 and b1-02.• Monitoring operation status from the PLC• Setting and reading constants• Resetting errors• Inputting multi-function commandsAn OR operation is performed between the multi-function commands input from the PLC and commandsinput from multi-function contact input terminals S3 to S8.Message FormatIn MEMOBUS communications, the master sends commands to the slave, and the slave responds. The mes-sage format is configured for both sending and receiving as shown below, and the length of data packets ischanged by the command (function) contents.The space between messages must support the following.Fig 6.59 Message SpacingSlave AddressSet the Inverter address from 0 to 20 Hex. If you set 0, commands from the master will be broadcast (i.e., theInverter will not return responses).Function CodeThe function code specifies commands. There are three function codes, as shown below.DataConfigure consecutive data by combining the storage register address (test code for a loopback address) andthe data the register contains. The data length changes depending on the command details.Slave addressFunction codeDataError checkFunction Code(Hexadecimal) FunctionCommand Message Response MessageMin.(Bytes)Max.(Bytes)Min.(Bytes)Max.(Bytes)03H Read storage register contents 8 8 7 3708H Loopback test 8 8 8 810H Write multiple storage registers 11 41 8 8Command message Response message Command messagePLC to Inverter PLC to InverterInverter to PLCTime (Seconds)24 bits long H5-06setting24 bits long 5 ms min.
