Modbus polling


In my Openhab installation (version 4.0.1) I have several devices connected via Modbus TCP. I have always encountered a slow reading problem that causes a 2 or 3 second delay, which makes some devices (for example anti-theft sensors) unusable to perform actions. Is there anything I can do to speed up reading? If I read the same device with a PLC I can make a reading every 10ms.


Check if you have any options which delay polling - such as timeBetweenTransactionsMs. I’ve got modbus 3.0.x binding to work with 150 ms interval with no issues. A lot depends on the end device, if you have a PLC which can keep up frequent readouts binding should be able to generate them.

Please note that there are some threading realted adjustments due to buggy Java 17 runtime which could impact some bindings: Consistent 100% CPU use of safeCall-queue thread

I configured my things as follows:

Bridge modbus:tcp:inim [ host=“”, port=502, id=1, timeBetweenTransactionsMillis=0 ] {
Bridge poller aree [ start=1, length=10, refresh=25, type=“holding” ] {
Thing data Test01 [readStart=“1.5”, readValueType=“bit”]


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