Abnormal Response; No Response - Omron 3G3MX2 User Manual

6-4 Modbus Communication (Modbus-RTU) Protocol

Abnormal Response

Response
If an error (aside from a communication error) is found in the query content, the Inverter returns
exceptional responses without performing any operation.
To determine the cause of an error, check the Parameter No. of the response. The Parameter No.
of the exceptional response will be the value of the query Parameter No. to which 80h is added.
Check the details of the error with the exceptional code.
Exceptional code
Code
6
* UV: During undervoltage

No Response

The Inverter ignores the query and does not respond if:
If the timer is set in the master to monitor response, but no response is returned within the set
time, send the same query again.
6-7
Slave address
Parameter No.
Exceptional code
Error check (CRC-16)
01h Specified an unsupported function.
02h Specified address does not exist.
03h Specified data has an unacceptable format.
21h Data is out of the Inverter's range for writing but for the holding register.
The Inverter does not allow this function.
Has attempted to change the register that cannot be changed during
operation.
Has issued the enter command during operation (UV*).
Has written into the register during trip (UV*).
Has written into a soft-locked register.
22h
Has attempted to change an I/O terminal that cannot be changed.
Has attempted to change the contact type of the RS (reset) allocation
terminal.
Has attempted to write into a register when auto-tuning was enabled.
Has attempted to write into a locked register while a password was set.
23h Has written into the read-only register (coil).
Has received a broadcast command (query of address 0).
A communication error is detected in receiving a query.
The query slave address is different from the slave address set for the Inverter.
The time interval between 2 pieces of data that configure the message is less than a 3.5-
character length.
Query data length is inappropriate.
The reception interval in a frame exceeds the 1.5-character length.
The error check code in the query does not match (CRC error).
Has received a broadcast command for each group (query of address 250 to 254).
Description
SYSDRIVE MX2 Series USER'S MANUAL (3G3MX2-A@@@@)
Etc.