I notice that if I setup to use RS485 in IOT2050 Advanced box, it will show setup time and hold time.

May you explain the usage of these settings?

And why it has only in the Advanced version?

 Hi Fe_lipe,

Should it be /dev/ttyUSB1?

per my test, I have to use /dev/ttyUSB1 instead of USB0 for IOT2050 Advance.

Fe_lipe

Hello,

The advanced and the basic IOT use different chips for the serial interface. The reason is a difference in the internal circuit due to the additional emmc on the advanced version. So while the X30 COM is acessible over /dev/ttyS2 on the Basic version, on the advanced it is /dev/ttyUSB0

The setup and hold times are only configurable on the advanced version, probably because its not part of the SoC. 

The theory behind these timings can be found on here. They are dependant on CPU frequency and the used baud-rate. I assume the unit should be in nanoseconds and must be converted from hex. I tried writing some ascii characters over RS485 using baudrate 115200 and the default values worked fine for me. 

Best regards!

Hi Arkom,

you can check which tty device is used with this command:

ls /dev/serial/by-id/ -l

I have an additional USB2Serial device, and on my IoT2050 the onboard is used as ttyUSB1 and the external device is ttyUSB0.