Baudrate not set on FTDI serial device after boot

[lokasoft]

I have got a RPI3b wit lastest SignalK server, the device has to USB FTDI serial devices, one set at 34800 baud for AIS data and other at 4800 Baud for sending GPS data to marifoon.
After reboot, the baudrate for the 4800 device is not set correct, it is at 9600 while the other device is set correct at 34800.
Only when I restart the SignalK service from the Web UI or console, the baudrate is set correct to 4800.

When the baudrate is correct and I unplug the FTDI device and plug it back in, the baudrate is back to 9600 until I restart the SignalK service.

What could be the problem?

Lex

[lokasoft]

After long search I found a conflict with RaspAp package that was also installed. The package was probing /dev/ttyUSB0 for presence of USB modems and sets the baud rate to 9600 during boot.

So problem solved.
Lex

[tkurki]

Thanks for sharing! Now other people can see this discussion and become aware of another app/daemon can modify things behind your back mechanism.

[lokasoft]

Coming from windows I was surprised this can happen, I would expect if one process has the port open, the other process cannot access the same port. This does not seems how it works in Linux.