Communication error | LabJack
 
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Communication error

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smarquis
smarquis's picture
Communication error

Hi all

I use a LJ U12, with Daqfactory. My LJ is connected to a ME-UBRE relay box.

The LJ is connected by USB to a W10 Home PC.

My application is very simple. The LJ is used for two channel data acquisition (pH / PO2). The ME-UBRE is used to switch some 12V relay and electrovalves.... simple....

I have a randomly error:

D0004-1009 GENERAL ERROR. WRITE ERROR.

When this error append, my application freeze (not the PC). I can't define why and when this error append. it could be after 45' running or one week.

What about this error? Any idea to fix it?

Azeotech say that isn't a Daqfactory problem..

Waiting for your idea..

regards

Stef

LabJack Support
LabJack Support's picture
Start here:

Start here:

https://labjack.com/support/app-notes/usb-communication-failure

When the problem happens, what is the minimum you can do (A through F) to recover?

If you remove all connections from the U12, except USB, does the problem go away?

 

smarquis
smarquis's picture
Hi!

Hi!

Most of the time, the process is not affected by the error message. Simply exit the dialog and the system continues to operate. Between each action of Daqfactory I put a delay of 200 [ms] ( Delay (0.2) )to give the system time to "digest" the set point. However, it rarely happens that I have to stop the application and restart DaqFactory. So to answer your question most of the time the action A is enough and more rarely the B. Never the others. I did not try to disconnect everything from the U12. Do I have to disconnect the MeUbrE box as well as the two pH and pO2 channels to do this test? Do you think the problem could come from the MeUBrE box?

Stef

smarquis
smarquis's picture
Hi

Hi

This morning there was again an alert. There was no disturbance on the process, I cleared the alarm without problems. It was not necessary to restart the application, as usual. I have another U12 and another MeUBRE relay box. I run a test with a U12 disconnected from the pH and pO2 inputs but connected with the relay box. This is not connected to the solenoid valves and the power relays. The USB cable is the same (5 meters) the brand and type are the ones you recommend. To be continued

Thnx for your help

LabJack Support
LabJack Support's picture
There are various ways to

There are various ways to approach it, but the idea is to try and identify if the issue is due to some particular hardware component in your system.  My preference is to first remove everything.  If the problem goes away, you then start adding things back to try and isolate what piece or pieces is the culprit.  If the problem still happens, you have immediately ruled out all the other hardware as a problem.

If your problem is related to EMI in your system, the most likely culprit based on your description is the relays turning on/off loads.  Perhaps do a test where you turn these loads on/off as much as possible to see if you can make the problem happen more often, which is great for problem solving.

The fact that your problem is temporary and generally clears up on its own is good.  Of course it is good to try and isolate and solve the root problem, but in parallel perhaps you can improve your software so when the problem does happen it does not impact your system.  An easy way to test this is to just disconnect/reconnect the USB cable while your system is running and see if your software handles things elegantly.