Modbus protocol adapter fails with multiple subscriptions

[prairiesnpr]

Expected behavior

I'm trying to poll multiple non-sequential holding registers from a PLC. I would expect to be able to poll multiple registers and publish values to the broker.

Actual behavior

Adding multiple subscriptions fails with:

java.util.concurrent.ExecutionException: java.lang.RuntimeException: com.hivemq.edge.modules.adapters.ProtocolAdapterException: java.util.concurrent.ExecutionException: com.digitalpetri.modbus.ModbusResponseException: functionCode=ReadHoldingRegisters, exceptionCode=IllegalDataValue
	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)
	at com.hivemq.edge.modules.adapters.impl.ProtocolAdapterPollingServiceImpl$MonitoredPollingJob.run(ProtocolAdapterPollingServiceImpl.java:241)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source)
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)
Caused by: java.lang.RuntimeException: com.hivemq.edge.modules.adapters.ProtocolAdapterException: java.util.concurrent.ExecutionException: com.digitalpetri.modbus.ModbusResponseException: functionCode=ReadHoldingRegisters, exceptionCode=IllegalDataValue
	at com.hivemq.edge.adapters.modbus.ModbusProtocolAdapter.readRegisters(ModbusProtocolAdapter.java:180)
	at com.hivemq.edge.adapters.modbus.ModbusProtocolAdapter.lambda$onSamplerInvoked$3(ModbusProtocolAdapter.java:158)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
Caused by: com.hivemq.edge.modules.adapters.ProtocolAdapterException: java.util.concurrent.ExecutionException: com.digitalpetri.modbus.ModbusResponseException: functionCode=ReadHoldingRegisters, exceptionCode=IllegalDataValue
	at com.hivemq.edge.adapters.modbus.impl.ModbusClient.readHoldingRegisters(ModbusClient.java:132)
	at com.hivemq.edge.adapters.modbus.ModbusProtocolAdapter.readRegisters(ModbusProtocolAdapter.java:171)
	... 8 more
Caused by: java.util.concurrent.ExecutionException: com.digitalpetri.modbus.ModbusResponseException: functionCode=ReadHoldingRegisters, exceptionCode=IllegalDataValue
	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)
	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)
	at com.hivemq.edge.adapters.modbus.impl.ModbusClient.readHoldingRegisters(ModbusClient.java:129)
	... 9 more
Caused by: com.digitalpetri.modbus.ModbusResponseException: functionCode=ReadHoldingRegisters, exceptionCode=IllegalDataValue
	at com.digitalpetri.modbus.master.ModbusTcpMaster.handleResponse(ModbusTcpMaster.java:181)
	at com.digitalpetri.modbus.master.ModbusTcpMaster.lambda$onChannelRead$5(ModbusTcpMaster.java:165)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

To Reproduce

<protocol-adapters>
        <modbus>
            <maxPollingErrorsBeforeRemoval>10</maxPollingErrorsBeforeRemoval>
            <pollingIntervalMillis>1000</pollingIntervalMillis>
            <publishChangedDataOnly>true</publishChangedDataOnly>
            <subscriptions>
                <subscription>
                    <addressRange>
                        <startIdx>36</startIdx>
                        <endIdx>39</endIdx>
                    </addressRange>
                    <includeTagNames>true</includeTagNames>
                    <includeTimestamp>true</includeTimestamp>
                    <messageHandlingOptions>MQTTMessagePerSubscription</messageHandlingOptions>
                    <qos>0</qos>
                    <destination>company/location/department/machine</destination>
                </subscription>
                <subscription>
                    <addressRange>
                        <startIdx>54</startIdx>
                        <endIdx>57</endIdx>
                    </addressRange>
                    <includeTagNames>true</includeTagNames>
                    <includeTimestamp>true</includeTimestamp>
                    <messageHandlingOptions>MQTTMessagePerSubscription</messageHandlingOptions>
                    <qos>0</qos>
                    <destination>company/location/department/machine</destination>
                </subscription>
            </subscriptions>
            <timeout>5000</timeout>
            <port>502</port>
            <host>192.168.200.10</host>
            <id>test_sub</id>
        </modbus>
 </protocol-adapters>

Either subscription by itself will work, just not multiple subscriptions.

I also tried setting unique destinations for each subscription, no change.

Details

• Affected HiveMQ Edge version(s): Official Docker Image, hivemq-edge:2024.2

[DC2-DanielKrueger]

Hallo @prairiesnpr, thanks for raising this issue. I tested it with the current master state and I did not run into that exception. There were quite some changes in the adapter handling and one might have resolved that problem. Is the bug still happening on your setup?

Best regards,
Daniel