I am trying to connect ventilation and air conditioning controllers to the Nexo system via a command card. From the Nexwell website, the control is supposed to be done by using logics that will send commands to the command card. For the time being, I am trying to simulate the external devices with a program on a computer with a usb -> rs485 converter connected, but unfortunately the computer does not capture data from the command card. The card also does not respond to ping frames, although I send frames that comply (in my opinion) with the standard, viz: "@12345678:ping" with the system address set to 18.52.86.120 (taken vividly from the examples in the documentation). Perhaps the frame format should be different, but nothing is written about this in the documentation, and there is no information on the Internet about it either. The manufacturer did not specify according to which protocol the communication with the card takes place. I have already tried sending frames in Modbus ASCII format with the above command in the data part of the frame, Modbus RTU, and also according to the standard described above. but all attempts failed. If anyone has had to deal with such a problem, please help. The whole problem stems from the fact that the output devices are operating on different transmission parameters, with completely different frame formats, and the intermediary program is supposed to translate commands from the command card into hardware control frames. Thank you in advance for your help, regards 
