onUpdate do not work when other programe changed the value

[KemingRen]

Future<int?> listenIntValue( int address, String key, ValueChanged<double?> onData) async { final client = await MBUtils.getClient(); if (client == null) { return null; } var unit = ModbusInt16Register( name: key, type: ModbusElementType.holdingRegister, address: address, onUpdate: (self) { onData(self.value); }, ); final res = await client.send(unit.getReadRequest()); if (res == ModbusResponseCode.requestSucceed) { print(unit.value); } return unit.value as int; } listenIntValue(100, "value", (v) { print("vvvv:$v"); });

There is a modbus device that controlled by other soft, I need watch one modbus address value，but when the value changed，the onUpdate function do not excute

[cabbi]

What is the res value of client.send?

[KemingRen]

unit.getReadRequest()

[KemingRen]

You can look at my code above

[KemingRen]

[cabbi]

I mean, does sending the request succeed? Can you please enable logs and show them?

[KemingRen]

Yes， This is the passed value that I printed, but it can only be listened to once

[KemingRen]

hey， my brother。

[cabbi]

Hi, I've asked you to enable logs and show them, but I still do not see them, Please add this line of code at beginning of your program and debug it on your PC so you will see the Modbus debug logs.

  // Simple modbus logging
  ModbusAppLogger(Level.FINE);

I've also asked you if sending the request succeeds and I'm still waiting this as well:

final res = await client.send(unit.getReadRequest());
print("request result: $res");