two usb RS232 adapter

[Hmissa]

hi all,

I m working in project that using two communication UART RS232.
my question is : Can i use two usb RS232 adapter in the same Rpi? /dev/ttyUSB0, /dev/ttyUSB1?
and if yes, the two UART have the same Rx buffer?

Best regards

[6by9]

hi all,

I m working in project that using two communication UART RS232.
my question is : Can i use two usb RS232 adapter in the same Rpi? /dev/ttyUSB0, /dev/ttyUSB1?

Yes, exactly that. You may need to look into udev rules to ensure they always enumerate to the same designation as there is no inherent guarantee of that with identical USB devices.

and if yes, the two UART have the same Rx buffer?

No, they'll be treated as totally independent, each with their own control setup and buffers.

[Steveng42]

I would be happy if I could get even one RS232 device to pass data to my Raspberry Pi3. The RS232 lines are showing good level signals and also on the Raspberry Pi side of the MAX3232 Breakout board. Could you post the image you use.

[Ernst]

I would be happy if I could get even one RS232 device to pass data to my Raspberry Pi3. The RS232 lines are showing good level signals and also on the Raspberry Pi side of the MAX3232 Breakout board. Could you post the image you use.

Do you know the difference between DTE and DCE ? (Hint: use google to search for rs232 using these terms)
It can be as simple as swapping pins 2&3, or (depending on the software) to link a few (DTR,RTS,DSR,CTS,DCD) pins.
https://en.wikipedia.org/wiki/RS-232
https://en.wikipedia.org/wiki/Null_modem