D.11 Communication Errorsu MEMOBUS/Modbus Error CodesA list of MEMOBUS/Modbus errors appears below.When an error occurs, remove whatever caused the error and restart communications.Error Code Error NameCause01H Function Code ErrorAttempted to set a function code from a PLC other than 03H, 08H, and 10H.02HRegister Number Error• A register number specified in the command message does not exist.• Attempted to send a broadcast message using other register numbers than 0001H or 0002H.03HBit Count Error• Read data or write data is greater than 16 bits. Invalid command message quantity.• In a write message, the “Number of Data Items” contained within the message does not equal twice the amount of data words(i.e., the total of Data 1+ Data 2, etc.).21HData Setting Error• Control data or parameter write data is outside the allowable setting range.• Attempted to write a contradictory parameter setting.22HWrite Mode Error• During run, the user attempted to write a parameter that cannot be written to during run.• During an EEPROM memory data error (CPF06), the master attempted to write to a parameter other than A1-00 to A1-05,E1-03, or o2-04.• Attempted to write to read-only data.23H DC Bus Undervoltage Write ErrorDuring an undervoltage situation, the master attempted to write to parameters that cannot be written to during undervoltage.24H Write Error During Parameter ProcessMaster attempted writing to the drive while the drive was processing parameter data.25HWriting into EEPROM DisabledAn attempt was made to write data into EEPROM by MEMOBUS/Modbus communications when writing EEPROM is notpossible. (When this error code occurs, an error message is displayed and the drive continues operation.)u Slave Not RespondingIn the following situations, the slave drive will ignore the command message sent from the master, and not send a responsemessage:• When a communications error (overrun, framing, parity, or CRC-16) is detected in the command message.• When the slave address in the command message and the slave address in the drive do not match (remember to set the slaveaddress for the drive using Z3-02).• When the gap between two blocks (8-bit) of a message exceeds 24 bits.• When the command message data length is invalid.Note: If the slave address specified in the command message is 00H, all slaves execute the write function, but do not return response messagesto the master.D.11 Communication Errors406 YASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual