When the piControl driver is reset, the modbus master is also reset.
If you have the 2 actions from above, the smallest interval is 1000ms. It is the smallest cycle divided by number of actions and by 4. This is the length of the pause after receiving a response before the next telegram is sent to a slave. If you have an action withan action interval of 1000ms and one with 2000ms, the timeout will be 500ms. The half of the smallest action interval is used. This is the time the master is waiting for a response from the slave. They are determined by a heuristic at the moment. The modbus master uses two timeout values. If you have no termination resistor that is reasonable error.
In the error messages in daemon.log the smaller number at the end of the line is the interesting one:ġ10 means Timeout: the response from the slave was not received fast enough.ġ2 means CRC-Error: The CRC of the response was not correct.
Oct 10 10:38:02 RevPi9693 piModbusMaster: modbus rtu action device: /dev/ttyUSB0, slave address: 26 function: 0x03, address: 1 failed -1/112345690/12ġ) Can you help me decipher the logmessages above ?Ģ) The manufacturer of the sensor says I should try and set the timout for the poll to 5 seconds - where can I do that ? If I have the cables connected correctly but no resistors or anything : If I do not connect cables - or if I insert a 120Ohm resistor between + and -> i Get this in the daemon-log : It is a simple 1-1 sensor-to-Pi connection of 2m. I looks like it is a problem on layer 1 or 2 when connecting RS485 sensor to the physical RS485-port on the RevPi Connect.
In my endeavour to make a simple Modbus-logger I am having problems reading modbus from the sensor.
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