Serial Communication

[JohnGalt]

Yeah, the error is still there. It seems to appear when loading a certain Labview function. It might have been the VISA name constant or some other thing, but It seems to not appear any more, or at least far less often. The PC was used in Kansas for doing some data capture, so it wasn't anything that happened then. I willdo a lillte more research on the errors and get back to you.

[K C]

You can also use MAX to see the status of your ports.

MAX (Measurement & Automation) in your NI menu. Open ports in tree, open COMx and have a look at the properties.

[JohnGalt]

Yes, the error appears when I load a VI containing a VISA name function. I don't know why this is, but it seems worrisome. I tried writing your test Open Coms vi thing, and I get an error saying the the number of bytes at the port is equal to the desired amount and there may be more data, I have tried going up to 800 on the expected, and nothing happens. But if I try to modify the actual number of bytes going into the VISA read it gives me a timeout error.  I knew how to use MAX to look at my ports, but thanks anyway. Did you want me to do something with MAX specifically?

[K C]

If this: 'the number of bytes at the port is equal to the desired amount and there may be more data' is the only 'error' you get I would not worry. It is not a error but a warning.

[JohnGalt]

The only problem with that is that when it says that, I don't get a reading. So I need to be able to make it continue running despite that error. If that would work, maybe we can actually get this program to work!

[JohnGalt]

Ok, I just realized that only half of the Meilhaus ports show up in MAX. The ones that do work the same as described in the previous message, but the others give me an error that says, "This port cannot be accessed or does not exist on the system." Why does it do this? I don't think I disabled anything, I don't even know how to. And I never did anything unusual to them. They just suddenly began not showing up. Odd.....

Message Edited by JohnGalt on 11-16-2005 02:32 PM

[K C]

It's is indeed strange that you only see half the Meilhaus ports.

I made a little program for you to communicate with your temperature controller. It send a reset, reads a setpoint, change that setpoint and read the setpoint again.

First try it with a loopback connector. Just run the VI, select the right com port and press OK. In the right hand array are the command and in the other two the received data is written (if any) One in HEX and the other in ASCII.

With a loopback connector the 'data rec in hex' must be the same as the 'data send' array.

Then try it on your instrument and post a screenshot if anything happens.

Good luck

[JohnGalt]

Thanks, I hope I can run it on my version though. I have Labview 7.0. i think you have 7.1. I shall try it though. By the way, how do I get a screenshot?

As I expected, it didn't work. Can I get you to put it in a picture file? I can try to do most of it based on your description, but not all of it, I think.

Message Edited by JohnGalt on 11-18-2005 12:20 PM

[K C]

Sorry, saved it as 7.0 VI now. I think you have to replace the serial VISA function. In the zip I also placed the screenshots.

Making a screenshot: Select the window (click on it) and press Alt-PrintScrn. The window picture is now on your clipboard. If you open a picture editor ( or word ) you can paste the picture there

Message Edited by K C on 11-18-2005 07:57 PM

[JohnGalt]

Yeah, for some reason half of the Meilhaus ports no longer show up in MAX, as mentioned before, but they still show up in Labview. Do you have any idea why this could be? It doesn't seem to affect anything, yet, but I want to make sure nothig may come of it later. I have tested your program with a loopback test, and it works beautifully, but I cannot test it with the instrument as it is being used for a sputter at the moment. I will test it when they are finished with it. Should be later today.

Thanks.

Message Edited by JohnGalt on 11-21-2005 12:24 PM