QtModbus doesn't reconnect programmatically

[AndyS]

Hi @Mark81,

If the device is not there and it is returning true when calling connectToDevice(), then this sounds like a bug. Can you report this on JIRA with an example there to reproduce it? Thanks.

[Mark81]

@AndyS Here the issue: https://bugreports.qt.io/browse/QTBUG-71282. It's the first time I created one - I hope I did it well!

[AndyS]

Hi @Mark81,

You did it right thanks!

[Pablo J. Rogina]

@AndyS if your issue is solved, please don't forget to mark your post as such! Thanks.

[AndyS]

@Pablo-J.-Rogina It's not my issue :)

[aha_1980]

Neither is mine :)

Anyway, closing this as there is nothing we can do here anymore.

[Mark81]

Sorry guys, but the issue is not solved at all! We've just discovered a documentation bug - but that wasn't the main issue.

The big problem, still there, is the second part of the question. Why does reconnection work only if triggered by a user click and it doesn't executing the same code using a QTimer?

[aha_1980]

@Mark81 don't connect the timer to the action, connect it to the corresponding slot instead.

[beecksche]

The QtModubus module has an asynchronous API. So by calling connectDevice() or disconnectDevice() your client is not connected/disconnected to the device immediately, but rather in ConnectingState/ClosingState. You have to receive the signal stateChanged() to ensure the connection state of your client. Only when the state of the client is ConnectedState your client is connected.

Also when you want to reconnect, I would ensure that you the state of the client is UnconnectedState.

Or just do a QHostInfo::lookupHost . Once the lookup was successfull you can connect again.

[Mark81]

@aha_1980 said in QtModbus doesn't reconnect programmatically:

@Mark81 don't connect the timer to the action, connect it to the corresponding slot instead.

Tried: nothing change.

[Mark81]

@beecksche said in QtModbus doesn't reconnect programmatically:

The QtModubus module has an asynchronous API. So by calling connectDevice() or disconnectDevice() your client is not connected/disconnected to the device immediately, but rather in ConnectingState/ClosingState. You have to receive the signal stateChanged() to ensure the connection state of your client. Only when the state of the client is ConnectedState your client is connected.

Also when you want to reconnect, I would ensure that you the state of the client is UnconnectedState.

I'm aware of this, but I have some thoughts about:

• I cannot wait such a long time: the built-in timeout is too long for my needs. Hence when I want to disconnect and reconnect I must use my own timeout timer

• I understand it might not be the best approach, but after calling disconnectDevice() I actually delete the object. It's not enough to force a disconnection?

• Anyway, I don't understand why it works clicking the action on the UI, even one right the other, and it doesn't by code, even waiting few seconds

[aha_1980]

@Mark81

Then either debug it yourself, or provide more code.

Are you sure ui->actionDisconnect->trigger(); does what you expect?

It should work the same way with a timer as it would work with a button.