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A9am
16th October 2013, 09:02
Hi,

I have a simple Qt code which sends a string to the COM port. The code is working with RS-232 but fails for RS-422.:confused: Do I have to make any other settings to make it work for RS-422? Or the same code should be fine for both?

Thanks
:)

kuzulis
16th October 2013, 10:00
Hi.

It depends from your RS422 device. Because some the cheap converters is used the additional manual switching of stream direction.

E.g. the RTS pin and so on. E.g. you should set the pin state to Hi before writing, and reset to low before reading..

But if your RS422 device supports by hardware the automatic mode of switching of the direction - that problems shan't be.

A9am
16th October 2013, 10:28
Hi,
Through hyperterminal the sending is fine. :(

syamcr
16th October 2013, 20:09
Do you use synchronous or asynchronous mode? i.e. do you use any handshaking lines or flow control? or do you use only the data lines without hardware or software flow control?