[jira] [Created] (PLC4X-156) The unitId is hardcoded to 0 which is the broadcast id in modbus

[Alvaro del Castillo (Jira)]

Alvaro del Castillo created PLC4X-156:
-----------------------------------------

             Summary: The unitId is hardcoded to 0 which is the broadcast id in 
modbus
                 Key: PLC4X-156
                 URL: https://issues.apache.org/jira/browse/PLC4X-156
             Project: Apache PLC4X
          Issue Type: Bug
          Components: Driver-Modbus
            Reporter: Alvaro del Castillo
         Attachments: Plc4XModbusProtocol.java

Trying to use the modbus driver, it is always trying to read and write from the 
slave 0 in the modbus slave/server. This identifier is the one used for 
broadcasting reads and writes to all the slaves in the modbus network. I have 
tested it with:

[pyModSlave|[https://pypi.org/project/pyModSlave|https://pypi.org/project/pyModSlave/]]

[diagslave|https://www.modbusdriver.com/diagslave.html]

and in the second case, if you try to read a register:
{noformat}
2019-11-27 08:29:29,837 ERROR modbus.handle_request Thread-1 invalid request: 
Function 3 can not be broadcasted{noformat}
This unitId should be a param but if it must be hardcoded, changing it to *1* 
is a fix.

The unitId is defined in:

[https://github.com/apache/plc4x/blob/develop/plc4j/protocols/modbus/src/main/java/org/apache/plc4x/java/modbus/netty/Plc4XModbusProtocol.java#L92]

I have tested in 0.4.0 release that changing the unitId to *1* fixes the 
problem. I have attached the file with this minor modification.


I can send a PR if you find the fix useful.

Thanks!

 

 



--
This message was sent by Atlassian Jira
(v8.3.4#803005)