Dear all,

I have read all the topics related to serial communication on the forum. But ı cannot open serial port to communicate with my device.

1)I have modified the CODESYSConfig.cfg like this:

[SysEthernet]
Linux.ProtocolFilter=3

[CmpSchedule]
ProcessorLoad.Enable=1
ProcessorLoad.Maximum=95
ProcessorLoad.Interval=5000

[SysCom]
Linux.Devicefile=/dev/serial

2) Add Symbolic Link to /pi folder

#!/bin/sh
# Script to start our application
sudo ln -s /dev/serial/by-id/usb-Prolific_Technology_Inc.USB-Serial_Controller-if00-port0 /dev/serial2
sudo ln -s /dev/serial/by-id/usb-DekTec_Digital_Video_BV_DTM-3237-OEM_DVB-S_DVB-S2_receiver-if00 /dev/serial3
sudo ln -s /dev/serial/by-id/usb-Silicon_Labs_CP2103_USB_to_UART_Bridge_Controller_PDBBRK006518-if00-port0 /dev/serial4
sudo ln -s /dev/serial/by-id/usb-u-blox_AG-_www.u-blox.com_u-blox_GNSS_receiver-if00 /dev/serial5
sudo ln -s /dev/serial/by-id/usb-Silicon_Labs_CP2103_USB_to_UART_Bridge_Controller_0047-if00-port0 /dev/serial6

I can not open serial port with this code. it's generate error. How can i solve this problem?

Hi,
which value has 'udiPort' in your application?

Should be 3 for using the usb-Prolific_Technology' interface
BR
Edwin

Hi Edwin,
Thank you for fast response.

In the morning, ı read your answer. I changed udiport value to 4 for using usb-DekTec_Digital_Video_BV device. After that port opened and ı sent some data to device. After a few attempts the device again generate error . I thought problem was from device. Changing the device did not solve the problem. The same error still occurs. Codesys can not open serial port.

Best regards

Hi Edwin,
I think I solved problem. I think there is an error in the code that I wrote. When ı tried with yours code, serial port opened without any error. If the problem persists I will bother you again.
Thank you so much
Best Regards.