Serial communication

[fabiovigliotti]

I am a new user a Labview 6.1and I am trying to learn how to get information out of the serial port. I am check on ni.com for more information, but I am still really confused. I don't know if someone could help me just to get started. Thanks

[wha@atmel]

Hi,

simply type "serial port" on this page into "ask" -
you will get a lot of info about this issue.....

regards
wha

[mikeporter]

One place to start is in the LV examples. There you will find several examples for talking to the serial ports. Just keep in mind that serial communications is the least standard of all types of instrument IO, so if there is any other way in the world to talk to your target device, it's a good idea to use it.

Of course, on the other hand, if you can find a GPIB driver for the instrument, sometimes all you have to do to convert it to a serial driver is change the VISA resource the driver is talking to.

Keep us posted. If you have any specific issues come up, hollar. BTW: what are you wanting to talk to?

Mike...

[felt]

Serial is confusing, and I found that the older examples, before things got switched to the VISA drivers, were easier to understand. There are some serial test vi's in the older code sections that help, and some vendors (Ontrak Controls) have serial test routine code that talks to the serial port - as a test, to see if you have the port configured correctly before you even start debugging your serial application! Serial is a slow protocol, too, so start out at maybe 9600 baud as you develop your own application. (I also found that I had to insert some 30 ms timer vi's into some of the examples - they were trying to run too fast for my serial port!) The Loopback.vi sample code is a good place to start experimenting.
-Dave

[fabiovigliotti]

Hi Mike,
Thank you for answer. To answer you question, I am trying to set up an experiment. I don’t have any GPIB and the only way is to use serial and parallel ports. I have a look-in amplifier, a photoelastic modulator, and a setting motor.
I am trying to understand how does Labview work. If I understood correctly, I am reading strings with Labview, is that correct? Also, hove can I tell my device to send information?
Well, if you have some time, I would really appreciate your help.
Best regards,
Fabio Vigliotti
fvigliotti@hotmail.com

[felt]

Fabio, go to www.ni.com and, in the Developer's Zone, search on, and download, Loopback.vi This will give some very basics on how to talk to, and read from, a serial port using Labview. I've not interfaced any parallel ports, but I suspect the logic is similar, maybe even easier. If you first draw up a logic diagram of what you want to do, the Labview programming will be easier. It would be highly advisable to also go through the learning tools and examples that Labview has.
- Dave

[mikeporter]

Also, you need to find the manuals for the instruments you're trying to control. There aren't standard commands for serial like there is, to some degree, in the GPIB world.

Mike...