Delta Electronics VFD-S manual ASCII mode, RTU mode, Exception, Meaning, code, Error message

Chapter 5 ParametersVFD-S Series

Example of an exception response of command code 06H and exception code 02H:

ASCII mode:

STX	‘:’
ADR 1	‘0’
ADR 0	‘1’
CMD1	‘8’
CMD0	‘6’
Exception code	‘0’
	‘2’
LRC CHK 1	‘7’
LRC CHK 0	‘7’
END1	CR
END0	LF

The explanation of exception codes:

RTU mode:

ADR	01H
CMD	86H
Exception code	02H
CRC CHK Low	C3H
CRC CHK High	A1H

Exception	Meaning
code
1	Illegal command code: The command code received in the command
	message is not available for the AC drive.
2	Illegal data address: The data address received in the command
	message is not available for the AC drive.
3	Illegal data value: The data value received in the command message
	is not available for the AC drive.
4	Slave device failure: The AC drive is unable to perform the requested
	action.

The AC drive receives the messages, but detects a communication error, thus, no response is returned, but there will be error message “CExx” displayed on the keypad of AC drive. The master device will eventually process a timeout condition. The xx of “CExx” is a decimal code, the meaning of the error message is below:

Error

message

5

6

7

8

9

10

11

12

13

14

Meaning

Reserved

AC drive busy:

The time interval between commands is too short. Please keep an interval of 10ms at least after the return of a command. If no command returned, please keep a 10ms interval at least for the same reason.

Reserved

Reserved

Check Sum Error: Check if the Check Sum is correct.

Watchdog Timer: The timer will reset to 0 after each valid Modbus communication message is received.

Frame Error: Check if the Baud rate complies with the data format. The command message is too short.

Command message length is out of range.

The command messages include the data that does not belong to ‘0’ to ‘9’, ‘A’ to ‘F except starting and end character (only for Modbus ASCII mode).

Revision August 2008, SE09, SW V2.61 5-73