topic Re: RS232, Flow-Bus protocol in LabVIEW

RS232, Flow-Bus protocol

david79 — Tue, 12 Jul 2005 11:43:12 GMT

Hello evryone,

I am starting a new project based on communcating with a digital mass flow instrument, with an RS232 interface Flow-bus protocol(Bronkhorst manufacturer). I have to developpe a program with Labview. According to what I have already checked out ( Net, labview examples, and forum ), it seems that I have to retrieve and send data to the instrument through excell for example. Sorry but I am completly new to all of this 🙂 (dde application). Is it possible to communicate with the instrument using just the VISA solution?

any help would be really great,

regards,

David

Re: RS232, Flow-Bus protocol

mikeporter — Tue, 12 Jul 2005 12:41:47 GMT

You should be able to. The question is whether or not the vendor will tell you how.

First step is to contact the vendor and ask for a copy their documentation on how to talk to their instrument over the serial port.

Next, it's possible that the vendor intended the Excel example to demonstrate how to access the device. Look at the Excel macros and see if you can tell how Excel is making the connection and then do the same thing. (Hopefully they don't have a custom DLL or the like).

If you would like help, post the Excel spreadsheet that can talk to the instrument and I will take a look at it.

Mike...

Re: RS232, Flow-Bus protocol

Ray.R — Tue, 12 Jul 2005 13:55:45 GMT

As Mike said..

Also:

Do you have the developer (or API) manual? Typically, you should have a list of commands that you can send to the instrument using serial port communication software such as "HyperTerminal". If so, then you can manually try out a few commands using H-T. The use the same commands to experiment with LabView code.

If you are able to use software like HyperTerminal, then using the VISA serial communication tools will be the simple way of implementing your solution. Here are some links which may provide clues on how to proceed. You can also do a search on VISA Serial communication.

Happy wiring!!

JLV

LINKS:

Link 1: Although this one talks about an error, it does provide instructions on how to setup the VISA session:
http://forums.ni.com/ni/board/message?board.id=170&message.id=99660&query.id=0#M99660

Link 2: Here are some examples: (good starting point):

http://forums.ni.com/ni/board/message?board.id=170&message.id=65873&query.id=0#M65873

Link 3: more info:

http://forums.ni.com/ni/board/message?board.id=170&message.id=86971&query.id=0#M86971

Re: RS232, Flow-Bus protocol

unclebump — Tue, 12 Jul 2005 14:19:00 GMT

Here is some info.

http://www.morechemistry.com/publ/labview/bronkhorst/vi_bronkhorst_02.html

http://www.morechemistry.com/publ/labview/vi_collection.html

Re: RS232, Flow-Bus protocol

mikeporter — Tue, 12 Jul 2005 15:46:41 GMT

Well there you go. It looks like you basically have two options: VISA which will be more efficient but might require more code to build command strings, and the company's DDE server which is simpler to use from the LV world, but much less effiecient and would possibly impose future compatability problems--like what happes if (when?) DDE goes the way of the dinosaurs?

Then also the DDE example pretty much stinks in terms of the quality of the code...

Mike...

Re: RS232, Flow-Bus protocol

david79 — Wed, 13 Jul 2005 14:12:34 GMT

Hi,

Thanks to JLV, mike, and unclebump fir ur help !!

I got Bronkhorst to send me a Labview example. They seem to use the DDE protocole....

Would any of u know where I could find some DDE notes. I have the labview Basic I &II, and the intermediate book, but no explanations on how to use the DDE VIs?

Thanks a lot,

David

Re: RS232, Flow-Bus protocol

mikeporter — Wed, 13 Jul 2005 15:32:09 GMT

Do a search in examples on "DDE". Also check Microsoft's website. There is a lot of info there.

Mike...

Re: RS232, Flow-Bus protocol

Molowe91 — Tue, 27 Mar 2018 10:55:03 GMT

Hi, did you connect a loose-end rs-232 to a digital module or did you connect rs232 to usb directly into the PC?

Re: RS232, Flow-Bus protocol

arteitle — Tue, 27 Mar 2018 13:26:15 GMT

The original poster's last post was almost 13 years ago, so I wouldn't hold my breath for an answer.