9-15
Data format [21] Auto tuning
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0 REV FWD Data portion
0: Without forward rotation command
1: With forward rotation command.
0: Without reverse rotation command.
1: With reverse rotation command.
Example) If P04 (motor 1 auto - tuning)=1: Forward rotation
0000 0001 0000 0001b=0101H
9-4-8 Communication Errors
Exception Response
When the inverter receives a message that does not contain communication errors but the message can not
be processed, the inverter will return an exception response. The exception response contains an error
sub-code in the data field that represents the problem.
Exception Response Errors
Sub-Code Name Causes
1 Illegal Function Received RTU Function other than 03, 06 or 16
2 Illegal Data Address • The starting parameter address is an unused inverter parameter.
• The starting parameter address plus the offset refers to inverter
parameter greater than the last parameter in a Function Code sort.
• The number of registers is greater than 16.
3 Illegal Data Value Data contains an out of range value for an inverter parameter
7 Negative Acknowledge • Requested data cannot be changed while the inverter is running.
• The inverter parameter function is owned by the network interface
option card and cannot be changed.
Communication errors
Communication errors occur when the inverter receives an invalid message. The inverter will not return a
response to a communication error. A code that represents the last communication error is stored in
inverter parameter M26. Typical communication message errors include parity, framing, and CRC errors.