MEMOBUS/Modbus Communications Error Code List

Table 1 lists the MEMOBUS/Modbus communications error codes.

When an error occurs, remove the cause of the error and restart communications.

Table 1. MEMOBUS/Modbus Communications Error Codes

Error Code (Hex.)

Name

Cause

01

Function Code Error

The PLC set a function code that was not 03, 08, or 10 (Hex.)

02

Register Number Error

  • The register number that is trying to access is not registered.

  • A starting number that was not 0001 or 0002 (Hex.) was set when broadcasting.

03

Bit Count Error

  • Read and write data quantities are more than the 1 to 16 range. (Command message data quantity is disabled.)

  • The data that was read from non-consecutive holding registers contained more than 120 bytes.

  • The data to be written to non-consecutive holding registers contained more than 60 bytes.

  • In the write mode, the number of bytes in the message is not the number of data × 2.

21

Data Setting Error

  • Writing control data or parameters made the settings go out of the permitted setting range.

  • A parameter setting error occurred when writing a parameter.

22

Write Mode Error

  • Tried to write a disabled parameter during run.

  • When there was a CPF06 [Control Circuit Error], the master tried to write a parameter other than one of these:

    • A1-00 [Language Selection]

    • A1-01 [Access Level Selection]

    • A1-02 [Control Method Selection]

    • A1-03 [Initialize Parameters]

    • A1-04 [Password]

    • A1-05 [Password Setting]

    • E1-03 [V/f Pattern Selection]

    • o2-04 [Drive Model (KVA) Selection]

  • Writes the read-only data.

23

DC Bus Undervoltage Write Error

During Uv [DC Bus Undervoltage], a Uv write disabled parameter was written.

24

Error Writing Data During Parameter Processing

Tried to write a parameter from the master during parameter processing on the drive side.

25

Writing into EEPROM Disabled

Writing into EEPROM write is disabled, but EEPROM write was executed from MEMOBUS/Modbus communications. When this error occurs, the keypad shows a message and the drive continues operation.

No Response from Slave

The slave ignores the command message from the master and will not send a response message in these conditions:

  • When a communications error (overrun, framing, parity, CRC-16) is detected in the command message.

  • When the slave address in the command message and the slave address for the drive side do not agree (Use H5-01 [Drive Node Address] to set the slave address of the drive)

  • When the time interval between the data of which the message is composed is longer than 24 bits

  • When the data length for the command message is not accurate

Note:

  • If the keypad shows CALL [Serial Comm Transmission Error], refer to “Troubleshooting” to remove the cause of the error, and try to do communications again. If the keypad does not show CALL, check U1-19 [MEMOBUS/Modbus Error Code] for the error and error type.

  • If you execute the write function code when the slave address in the command message is 00 (Hex.), all of the slaves will execute the write command, but they will not send response messages to the master.