Today I made a little program with VISA serial. The device connecting to PC has a "COM4" displayed in Windows device manager. Right click on the "COM4" icon I can setup the Baudrate etc (9600 bit/sec; Databit 8 ; no parity; stopbit 1) In the labview program, I made a different setup (9600bit/sec; Databit 7; Even parity; stopbit 2) The data can still be correctly receivd. Why is it lik that? Can anybody give a little explanation on it? Thanks in advance.

Is YOUR device a true RS232 device? Or is it a USB device with a provided driver that "appears" as a virtual COM port? Do you have a single USB cable that goes from a USB connector on your computer to a USB connector on your device? Just because your device driver creates a virtual COM port does not mean it is RS232. If it is a purely USB device and is never converted to RS232 (like a lot of small cpu boards are) then the Baud Rate, Data Bits, Parity and Stop Bits have no effect. They have no function. The connection is defined by the USB protocol and the are no settings that you can change. I have a similar device and the user manual clearly states that the Baud Rate does not matter. But the Flow Control Does. Set to NONE. What does the user manual of your device say?

if the device is sending data slowly it may match when even parity is correct then no parity does not perform the check. When the device has more then one bitperiod between two characters then two stopbits are ok just as one stopbit.

I don't know why it works. It shouldn't. What's the device?

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