Honeywell HC900 User Manual
Page 49
Modbus RTU Exception Codes
Introduction
Revision 10
HC900 Hybrid Controller Communications User Guide
41
12/07
Table 5-1 Modbus RTU Data Layer Status Exception Codes
Exception
Code
Definition
Description
01
Illegal Function
The message received is not an allowable action for
the addressed device.
02
Illegal Data Address
The address referenced in the function-dependent data
section of the message is not valid in the addressed
device.
03
Illegal Data Value
The value referenced at the addressed device location
is not within range.
04
Slave Device Failure
The addressed device has not been able to process a
valid message due to a bad device state.
06
Slave Device Busy
The addressed device has rejected a message due to
a busy state. Retry later.
07 NAK,
Negative Acknowledge
The addressed device cannot process the current
message. Issue a PROGRAM POLL to obtain device-
dependent error data.