Still having VISA read issue

[Wolleee]

I currently have 2 USB devices uses prolific converters on them. The Vise read is configured to timeout every 2 seconds. Now the visa read works sometimes and other times the application just freezes.  Very random.  Is this some sort of driver issue or could these prolific cables be causing the application to freeze?  Here is an image when in the highlighted state.

[nyc_(is_out_of_here)]

---

@matt198717 wrote:

I currently have 2 USB devices uses prolific converters on them. The Vise read is configured to timeout every 2 seconds. Now the visa read works sometimes and other times the application just freezes.  Very random.  Is this some sort of driver issue or could these prolific cables be causing the application to freeze?  Here is an image when in the highlighted state.

---

You were adviced to get new USB - RS232 devices.

Since you apparently haven't done so, what is the point of rehashing this issue again?

Duplicate post at http://forums.ni.com/t5/LabVIEW/visa-read-and-write-to-text-file-freezes-application/m-p/3138713

[Wolleee]

Yes,

Im working on getting new cables.  It just seemed odd to me that it would cause the application to freeze.  I just thought it would have a misread or something.  Maybe someone could explain this to me.  Im sure there is more going on than i see.

Thank you.

[billko]

---

@matt198717 wrote:

Yes,

Im working on getting new cables.  It just seemed odd to me that it would cause the application to freeze.  I just thought it would have a misread or something.  Maybe someone could explain this to me.  Im sure there is more going on than i see.

Thank you.

---

Since I couldn't find a reference to any posts in the aforementioned thread about getting new cables (deleted posts???), I am going to assume you misunderstood what the suggestion meant.

In this case, I'm guessing the recommendation was actually to get an adapter with a different chip set.  The general consensus is that adapters with the Prolific chip set don't get along with LabVIEW very well.  It could cause exactly the problems you've described.  The vague reference to a driver issue that I saw in one of the earlier posts might be a reference to that incompatibility.

[Wolleee]

Yes,

I agree.  Im assuming it is simply those adapters.  I have another thread going that i asked for reliable rs232 to usb adaptors and am getting away from these adaptors.  They work for most things ive done in the past, but recently when interfacing with labview have not been sufficent.  It was suggested i move to FTDI chip adaptors and make sure they are real.

[billko]

LOL I was just reading that thread, making my comments obsolete.  🙂

[nathand]

If you haven't already tried this, right-click the VISA Read function and change the mode (from Synchronous to Asynchronous, or vice versa - whichever one reverses how you have it now). That's fixed problems for me in the past with questionable USB-Serial drivers (don't remember the brand, but could have been Prolific).