Serial Loopback Test in NI VeriStand

[Andrew_B]

Overview
This example demonstrates how to perform Serial I/O in NI VeriStand through a loopback test.

Description:
The Serial I/O is performed through LabVIEW code (based on the Basic Serial Write and Read example) compiled into a LabVIEW model (.lvmodel) following the steps in Using Models Created with LabVIEW in NI VeriStand. A tester VI was also written to demonstrate how the NI VeriStand Engine performs the loopback test.
Before using this code, first follow the instructions in How to Do a Serial Loopback Test to set up your serial cable for a loopback test.

-Serial Operations.vi
This VI performs the Serial I/O operations and can be compiled into a LabVIEW model. It has the following states:

• State 0: Idle
• State 1: Initializes Serial port COM1
• State 2: Writes the value of the double "Write" control to the serial port
• State 3: Reads a double value from the serial port and outputs it to the "Read" indicator
• State 4: Closes the serial port

-VeriStand Engine.vi
This tester VI demonstrates how the NI VeriStand Engine calls Serial Operations.lvmodel. The different VeriStand Engine elements involved are:

• "Serial Operations" model
• "Increment" calculated channel
• "Modulus" calculated channel
• Mapping between the "Modulus" and the "Action" channels
• Primary Control Loop rate = 4 Hz = 250 m

Steps to implement or execute code
To implement this example:

• Run the VI
• (Optional) Turn on the Highlight Execution to see the flow of the VI

Requirements
Software
LabVIEW 2012 or compatible
NI VeriStand

Hardware
-

**This document has been updated to meet the current required format for the NI Code Exchange.**