Can't talk to BK8500 after upgrading to LV2013

[SteveRobbins91302]

For years I've been using LabVIEW 8.2 on my Windows XP computer to control an electronic load (BK PRECISION 8500).

The instrument came with a "USB to TTL" serial converter cable (part number IT-E132).  This has "TX" and "RX" LEDs on it.

When I installed the trial version of LabVIEW 2013, I copied the BK drivers over to the driver folder for LV2013, opened the VI tree, and saved everything.  So all the VIs are updated.

But I just can't talk to the instrument with LV2013.  The "TX" LED on the cable flashes, but the "RX" LED never does.  The "link" indicator on the front of the instrument lights up.

Everything still works fine when I go back to LabVIEW 8.2.

[Dennis_Knutson]

Did you install a version of NI-VISA that is compatible with 2013? I don't believe that there is a version compatible with both 8.2 and 2013.

[SteveRobbins91302]

That didn't fix it.  I upgraded to LabVIEW 2014 (8 hours to download and install, $1.5k fee) and I have the same problem: I can't communicate with the BK8500 electronic load.  But I can still communicate with all the other instruments in my setup.

When I try to talk to the BK8500, the "TX" LED on the USB-to-TTL adapter cable flashes and the "link" indicator on the front panel lights up, but the "RX" LED on the adapter cable is always dark. 

I had to remove LV 8.2, and a bunch of other stuff from my old hard drive to make room for the massive web insaller download, so I can't verify that the BK8500 still communicates using LV 8.2.  But I verified that a couple of days ago when I first had the problem after installing the demo version of LV 2013 (now also uninstalled) that came with the myDAQ.  FYI, the myDAQ DVD didn't include NI-VISA, so I was using the old version of NI-VISA that came with LV 8.2.  But I know I've got the latest NI-VISA now, when I installed LV 2014.

I tried reinstalling the USB driver for the USB-to-TTL adapter cable that came with the BK 8500 load.  That didn't fix it either.

I noticed that if I change the baud rate to 4800 (default is 9600) then both the "TX" and "RX" LEDs blink, but the BK8500 still doesn't respond to commands, and the recieve string is always empty.

Then I used NI-VISA interactive control to look at the attributes.  The attribute at the bottom of the list "Is Port Connected" has "Invalid property value" in red.  Could that have something to do with the problem?

[Dennis_Knutson]

The property is only for NI converters so you should ignore it.

Please be specific as to the version of NI-VISA that you installed. Attach a screenshot of MAX that shows both the com port and software installed.

Have you tried a program such as hyperterminal or putty to talk to the instrument?

[SteveRobbins91302]

I didn't see any attachment.

I think I got it working, but I'm not quite sure how.

I opened MAX to get the verison numbers (LV 14.0, NI-VISA 14.0).  Then I opened the "Devices and Interfaces" part of the tree.  COM6, the port I'm using for the BK8500, showed an icon of a 9-pin D-SUB connector with a yellow triangle on it, and an exclaimation mark inside the triangle.  When I clicked on COM6, the there was ta tab at the bottom of the data pane that read "Port Settings Conflict".  There was a column of VISA settings, and a column of Windows settings.  It seemed to be asking which column to use.  The only difference between the columns was the buad rate (VISA=9600, Windows=4800).  First I clicked the radio button to select the VISA column, but the BK still wouldn't work.  Then I clicked the other radio button to select the Windows column, and suddenly it started to work.  Or at least I was able to send a simple command at worked: I'll do more testing now.

[SteveRobbins91302]

It's not quite there yet.  I can set the instrument, but I can't read anything back.  For example, I can set the current level and turn the inputs on or off, but I can't read the device ID code or any of the front panel data (voltage, current, power).

[ChacAttack]

Hello,

You mentioned that you dragged and dropped the instrument drivers over, but did you download the newest driver for the BK8500?

You can find it here.

[SteveRobbins91302]

I tried the newest driver.  BTW, it has only minor changes from the original, and is still probably the worst LV coding I've ever seen.

I can communicate with the BK8500 when I make a simple VI that only talks to the BK8500.  But when there are a bunch of other instruments also being controlled, the BK8500 seems to get random errors.  I have five instruments (including the BK8500) connected to USB ports on the computer (no hub).

I'm just going to give up for now, and add some dialogs to my test software to prompt me to set the BK8500 manually.  It will mean a whole day of pushing buttons, but at least I can finally get my data.

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[ChacAttack]

Hi Steve,

I'm sorry that you are experiencing these errors. I will escalate this issue to my colleagues who may be able to offer further steps you can take. If you would like me to do this, kindly post your code (or you may email it to us). Please also include screenshots of any errors/warnings that you are seeing. This information will be critical to troubleshooting this further. I am happy to help you.

[zou]

Had a lot of trouble with BK5xxx last year.

The driver is not working correctly.  End up making a lot of change ourselve.

The firmware is not robust either.

The instrument has timing problem.  It's own clock is not reliable.

To make sure the insturment get the message, some commands we have to send repeatly.

We use the highest baud rate: 38400.

Make sure the BK address is correct.  Make sure it is unique.