RS232 connection issue with 4KEX100-H2

RS232 connection issue with 4KEX100-H2

Here’s a troubleshooting guide for the RS232 connection issue you’re facing with your 4KEX100-H2 product.
Product model: 4KEX100-H2

Step 1: Check the RS232 Cable Connection

Double-check if the connection method of the RS232 cable between the HDMI extender and the control/controlled device is correct. The connection should be as follows:

  • TX-RX
  • RX-TX
    rs232 graphic

If any of the pins are not connected correctly, it can lead to communication errors. Make sure the connectors are securely fastened, and the cables are not damaged.

Step 2 Perform an RS232 Loopback Test

Perform an RS232 loopback test to see if the HDMI extender’s RS232 pass-through function can work normally. Use software like UartAssist to check if the pass-through function is working right.

Step 3 Connect the Devices Directly

Try connecting the control device and the controlled device directly without using the HDMI extender. Then check if the RS232 connection works.
If the connection works without the extender, it means that the extender might be the problem; if the connection still doesn’t work, we may need more information to further troubleshoot.

If these guides don’t help and this problem persists, feel free to contact our tech support at