The Industrial Raspberry Pi Forum

Hi,

I have been trying to connect a RevPI Core S to a machine that data over rs232 to catch this data i want to connect the machine using a rs232 to usb and then by using Python & pyserial read and process the data. I have verified that /dev/ttyUSB0 exists and i have configured pyserial with the same settings as the machine (baud rate, parity etc.)

However this is where im having problems im not getting any data in /dev/ttyUSB0 and im having trouble figuring out what to do or if i have missed anything.

Hardware:
RevPI Core s
1P3FFCB-USB-SERIAL (Serial to usb converter)
Mystery machine that sends data over serial

Thanks in advance for any help,
// Victor

Hey Victor, I have created a test setup and hope it shows how easy you can transfer serial data:

1. Start miniterm 2. Set local echo on 3. Monitor Pin 2 of D-SUB-9 plug - Pin 5 is GND 4. Type something into miniterm

Here is the result: I have also used a USB-FTDI converter so it is the same driver as you use, I think. I must admit that I used a beta RevPi Bookworm OS image on my device:
Some ideas for your troubleshooting:

• Use an oscilloscope or a logic analyzer to monitor the data lines
• How about the edges of the rectangle signals?
• How about echoes?
• Maybe you need to use terminating resistors - yes I did not use them, but this was just a quick test with short cables