LabVIEW
Where Do I Start?
bobmacklin wrote:
We need to create an interface between the computer and the stepper motor conrtoller. I ASSUME that would be a USB port.
First, you need to decide on a stepper motor controller and what interface you want it to have. Personally, I would look for something with a serial (RS-232) interface. Then you just use VISA to send your commands to the stepper motor through a serial port (most likely a USB-232 converter). There are a few examples in the example finder (Help->Find Examples) for serial communications.
Great, hopefully your knowledge of other languages will help you get started. If you haven't seen already there are lots of free online tutorials for learning LabVIEW and some other NI tools. Checkout the links at the bottom.
https://decibel.ni.com/content/docs/DOC-40451
Now for your particular task if you are using a COM port to talk to a device, I usually start with a shipped exampled. Go to Help >> Find Examples. And search for Simple Serial. Here is an example that will open a COM port using a VISA resource, send a command, wait some amount of time, then read the response. Look at the block diagram to see how it opens the port using various settings, where it sends the *IDN?\n request, where it waits, and where it reads the response.
Real applications are usually more complicated then this, and hopefully use syncronous serial modes where it can find the end of the message for you based on a termination character. This is usually wrapped in a while loop that keeps executing until the user stops it somehow, usually by closing the window and using the event structure but that might be a bit advanced. Most new developers people just drop a button on the front panel to stop which is the more simple, but less scalable option.
