Modbus error codes – Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER User Manual
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Publication 1404-UM001F-EN-P - November 2009
Chapter 4 Communication
The data table number of error request and element offset of error
request in the
table is updated with the first Modbus
address of the table and element offset that the incoming request
packet attempts to write to.
If a client device requests too large a data size, the power monitor
returns the requested data padded with zeroes up to the requested
data size rather than returning an error.
When the
table is used together with
Modbus, the value for element 1 should be 1000.
The value for element 0 of the
table is the first
Modbus address of data table written to last.
For function code 03, 04, and 16, the number of words of user data is
limited to 100. If it is over 100, exception code 3 will be returned to
the master and error code 3 occurs.
Modbus Error Codes
Error
Code
Description
Meaning
Response
Exception
Code
0
No error.
None
1
Function Code
cannot Broadcast.
The function does not support Broadcast.
Nothing
transmitted
2
Function Code not
supported.
The controller does not support this
Modbus function or sub-function.
1
3
Bad Command
Length
The Modbus Command is the wrong size.
3
4
Bad Length
The function attempted to read/write past
the end of a data file.
3
5
Bad Parameter
The function cannot be executed with
these parameters.
3
6
Bad Table
Number
The table number does not exist.
2
7
Bad Modbus
Address
The function attempted to access an
invalid Modbus address.
3
8
Table Write
Protected
The function attempted to write to a
read-only table.
3
9
Table Access
Denied
Access to this table is not granted.
2