LabVIEW Serial Communication Detailed Explanation

I have wanted to make something similar for a long time. I happened to learn LabVIEW this semester, and I handed in this as my homework, a "serial oscilloscope" host computer based on LabVIEW.

1. Program interface:

Function introduction: The upper left is the serial port receiving area, and the lower part is the serial port character sending area. The right side is a waveform chart. Each time the data sent from the serial port is formatted with f% inside the program, it is displayed on the waveform chart.
Button introduction: From left to right, send button; clear count button; open/close serial port button; clear receiving area data; clear waveform chart; save waveform; exit program.

2. Main program flowchart:

Introduction to the main program flowchart: The main program flowchart mainly consists of three states: program initialization, response to program events, and program exit.

State Init: Program initialization, mainly set the OpenCom button, serial port status, serial port receive string, waveform icon, TX/RX count and other controls to False or clear. The initialization state is executed only once, and then enter the Event state.

State Event: Program event response, consisting of an event structure, a total of 8 events need to be responded: Open/CloseCom button event; serial port number or baud rate change event; send button event; clear count button event; clear receiving area button event; clear waveform area button event; save waveform button event; menu selection event; exit button event. If you press the exit button in this state, you will enter the state Exit, otherwise the program will always run in this state.

Status Exit: The program exits. The opened VISA handle must be closed before exiting.

3. Serial port receiving program block diagram:

Serial port receiving program flowchart introduction: When the serial port status is true, call the serial port property node "Bytes at Port". If there are X bytes of data in the serial port buffer, receive X bytes of data. Finally, use a state machine to implement the judgment of two adjacent strings. If the serial port receives the time between two adjacent strings for more than 50ms, it is judged as two independent strings; if it is less than 50ms, the two strings are automatically spliced.