Modbus Binding connect Samson Web-Modul

Add-ons Bindings
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Hi,

I am new on openhab and I tried to connect with the modus binding to Samson Web-Modul TROVIS 5590. But I get these messages:

2022-10-09 09:35:46.821 [WARN ] [rt.modbus.internal.ModbusManagerImpl] - Try 2 out of 3 failed when executing request (ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_INPUT_REGISTERS, start=99, length=1, maxTries=3]). Will try again soon. Error was: net.wimpi.modbus.ModbusSlaveException Error Code = 1 [operation ID b5cc9863-07ec-4476-bd89-b3d8e290574d]

2022-10-09 09:35:47.007 [ERROR] [rt.modbus.internal.ModbusManagerImpl] - Last try 3 failed when executing request (ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_INPUT_REGISTERS, start=99, length=1, maxTries=3]). Aborting. Error was: net.wimpi.modbus.ModbusSlaveException Error Code = 1 [operation ID b5cc9863-07ec-4476-bd89-b3d8e290574d]

I am not so familar with modbus but I am able to connect and read registers via perl MBClient without any problems from the same machine.

Could this be the limitation …" The binding does not act as Modbus slave (e.g. as Modbus TCP server)."?

Thanks for all help!

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The target device has responded to whatever you asked openHAB to do to it - it has rejected the request. “Can’t do that”.

Most likely a register type or address error, possibly a length issue, e.g. attempting to read just one of a double-value pair.

That’s really unlikely, as you got a response.
I’ve no idea what a Samson Web-Modul TROVIS 5590 is, but it is probably not a Modbus Master device?

If you cannot work it out, show us exactly what parameters you use for that, and how you have configured openHAB

The usual cause for this sort of thing is +/-1 register address confusion. openHAB uses register address (starting at 0) and some other documents/utilities use register numbering (starting at 1). Register number 20 is addressed at 19, etc.

Also beware confusion between hex asnd decimal addresses…

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Hi rossko57,

thank you very much for all your hints!

First of all I use type="input" instead of type="holding" and the second mistake was the wrong readValueType. A closer look at the very good openHAB Modbus documentation then solved all the issues.

Thanks!

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