Transactions; Modbus Error Codes - Siemens SENTRON 3WA System Manual

Modbus TCP

5.4 Transactions

5.4 Transactions
Every Modbus write frame in the 3WA system (Modbus function code 16 or hex 0x10)
constitutes a transaction.
A transaction is only executed if all the parameters contained in the frame are accepted by
the target components.
Note
Even if one parameter in the frame is rejected by the target component, all the other
parameterizations from this frame are undone.
If a positive acknowledgement of the Modbus write frame is received, all the parameters
contained in the frame have been accepted by the system. Conversely, an error message for a
Modbus write frame indicates that none of the parameters of the system have been changed.
5.5

MODBUS error codes

The COM190 communication module supports the following Modbus exception codes:
Exception code
1 (hex: 0x01)
2 (hex: 0x02)
3 (hex: 0x03)
4 (hex: 0x04)
6 (hex: 0x06)
38
Description
Modbus function code is not supported.
• Start address is not located at the start of a data point of the 3WA system.
• Start address is not located at the start of an existing data point in the con-
crete 3WA circuit breaker.
• An attempt is being made to read beyond the end of the Modbus register
map.
Structure of the frame is incorrect.
• A parameter contains an invalid value.
• A command contains invalid arguments.
• A parameter or command is write-protected.
• A command for switching of the 3WA circuit breaker or digital outputs takes
place when remote switching protection is active.
• The Modbus TCP whitelist is active and the active MODBUS TCP connection
has insufficient rights for writing a parameter or the command.
• Writing is taking place across a gap in the Modbus register map.
• A data point which does not exist in the concrete 3WA circuit breaker is being
written.
• A parameter or command is not being written in full.
• The first data point is only partially read.
A parameter is currently being changed by another source. The parameterization
procedure must be repeated at a later time.
3WA Air Circuit Breaker Communication
System Manual, 11/2021, 92310000004-02