Posted 23 May 2017 hello everyone, I'm trying to connect PC with Micro830 with RS232 cable for transfer serial data. However, the PLC can not receive the character from PC. I used ARD function block to read the characters from PC. there is no error and the output of ARD function block is 0 when I debug ladder programme. the serial communication state LED illuminated once I send a character from PC to PLC. the channel of input is 2 which is the embedded serial port. I use an adapter from USB to RS232. Email: jeremietang531@gmail.com Share this post Link to post Share on other sites
Posted 23 May 2017 If you are using a USB to serial adapter, are you confident that this adapter works? Have you used this adapter before on another project? You may want to find some way to test the adapter like by using it with an old computer/old project that you used in the past. Another option is to use HyperTerminal and perform a loopback test on your serial cable to make sure the serial port and the USB to serial adapter works. Search for "use HyperTerminal to test serial port" and you should find some websites with detailed suggestions on this. Share this post Link to post Share on other sites