How do I determine if data is being sent to the HMI's serial port?

How do I determine if data is being sent to the HMI's serial port?
none 0.0 0

I am looking for a method to monitor if I’m collecting data into a serial port. I have code that was functioning on a different HMI, but am trying to get it to work on CMT3092X and am not having any luck yet. Do you have any serial communications strategies/debug tools that you can recommend?

  • HMI Model: cmt3092x
  • EasyBuilder Pro Version:V6.07.02.542
  • Serial Number or supplier:

Hi @Brentr,

Thank you for contributing to our forum! What driver are you using within your project? Also, what is the device ID and COM port used by this driver?

Example: The device below is "Local Device 1 and it is registered to COM 1.

Also, can you please advise what HMI model the “other HMI” is?
Thank you!

I am using Free Protocol to talk to “LT2000 HA” which is a laser with COMM 3RS232 interface (9600 baud. I see that I’m getting a string back now by modifying the code but hoping there is an easy way to ‘sniff’ serial port for future reference.

The code originally worked on MT8053IE.

If i want to use simulator with RS232 device, can I plug this into my laptop and use ONLINE SIMULATION? Do i need to redefine the port number in the project so it matches the COM port # in my laptop?


Currently, the easiest way to determine if you are receiving data is to use the “INPORT()” command. Also, it is possible to perform an online simulation with an RS-232 device as long as you configure the serial port you intend to use within the driver for your USB-RS-232 device in the device manager:

  1. Open the “Device Manager” in windows and locate the USB-RS-232 driver:

  2. Ensure that the COM port used by this driver matches the COM port used within EasyBuilder Pro: