Modbus Error connecting to endpoint ModbusIPSlaveEndpoint

Good day,

Working on a brand new instance of openhab 3.4.0 (Docker) and I’m unable to get the Modbus binding working.

The TCP slave is online, but other nodes are unable to communicate with them


Error with read: Error connecting to endpoint ModbusIPSlaveEndpoint [address=, port=502]

TCP Modbus:

UID: modbus:tcp:fc615f00df
label: Modbus TCP Slave
thingTypeUID: modbus:tcp
  rtuEncoded: true
  connectMaxTries: 1
  reconnectAfterMillis: 0
  timeBetweenTransactionsMillis: 60
  port: 502
  timeBetweenReconnectMillis: 0
  connectTimeoutMillis: 10000
  afterConnectionDelayMillis: 0
  id: 2
  enableDiscovery: true


UID: modbus:poller:4a2f9f7f70
label: Regular Poll
thingTypeUID: modbus:poller
  length: 120
  start: 20
  refresh: 1000
  maxTries: 3
  cacheMillis: 50
  type: holding
bridgeUID: modbus:tcp:fc615f00df

Does someone have any idea what is going on?

Good day too!

I have the very same issue (while working with modbus and an inverter by SMA) and I don’t know where the problem is.
Anybody some suggestions?

Are you sure about the RTU-Encoding over TCP? Try disabling it.

For me it was the ID that needed to be 3 instead of 2. However I’m still working on this as the item config is still not cleare to me. Did you got your’s working?

Well I got it working, will post the info soon!