7 replies to this topic

[Rakete]

Hello, I´m new to Labjack and want to count impulses on the CNT input. I connected a switch and a pulldown resistor. Now i want to reset the counter, but it happens nothing, it stay allways on 29819054. I tried to reset it with LJCounter V1.07, and with Labview, and with Profilab Expert 3.0, and nothing works! And when i toggle the switch, the counter dosen´t increase its value. I run the LJTest and everything seems fine. Driver Version is V1.210, and the Labjack is 1.100. What else could i try? Is the CNT input broken? Maybe, but why can´t I reset it? I never connected overvoltage to it... Please help me! Thanks! Rakete

[LabJack Support]

Strange. The U12 seems to be operating fine, except that the counter is stuck on a big number. Power-cycle the U12, and make sure only one software application is running at a time. If you continue to see the same problem I suggest you contact [email protected] so we can take further action.

[LabJack Support]

Also, the digital I/O is normally low on the U12, so you would use a jumper from +5V to create test counts.

[Rakete]

Hello Support, thank you for your answers! Yes, its very strange! Everything else works fine, except the CNT. Ok, I will try to restart my computer, then the Labjack is resetted, too, and I will start only one software to try it again. Next step will be to try that on an other computer... What do you mean with "the digital I/O is normally low on the U12, so you would use a jumper from +5V to create test counts"? I measured the +5V and the Ground on the input CNT with an oscilloscope to be shure that the Signal is fine. The Ground is really zero, the +5V is 5,12V, and there is no distortion on the signal like chattering. What I else noticed is that when I switch on the STB on the LJCount, then the value of the counter is decreasing one number to 29819053. 32 bit resolution means that the counter can count from 0 to 4294967296. The displayed 29819054 is then not something 2^x. The Labjack is resetted by diconnect the USB and reconnected? There is no switch inside? For a real hardware-reset? And the U12 firmware can´t be updated? What else can I try? Send it back to the store I bought it? But I don´t have warranty any more... Thank you for your support! Maik

[Rakete]

Maybe it´s because I´m using an laptop? An quite old one? But there is no difference on USB compared to the RS232 with lower voltage on the port? Then I wouldn´t measure more then +5V on the screw terminal?

[Rakete]

Ok, I checked it with an other PC. No change... What I recognized is a difference between the examples LJlogger and LJcounter: These show different values, 29819340 in LJlogger, and in LJcounter 29819054. And in both I cant reset...

[LabJack Support]

What do you mean with "the digital I/O is normally low on the U12, so you would use a jumper from +5V to create test counts"?

On our newer devices (U3/U6/UE9/T7), the digital inputs are pulled high (3.3V) internally. So to create counts you would tap a wire connected to GND. But on the U12, the digital inputs are pulled low internally, so to create counts you would tap a wire connected to +5V.

What else can I try? Send it back to the store I bought it? But I don´t have warranty any more...

If you want to send it back to us directly, we can take a look at it. Contact [email protected] to follow-up on that.

[LabJack Support]

The counter problem here was that the watchdog was stuck on.  See the new item #6 on the U12 Hardware Troubleshooting page:

 

http://labjack.com/s...troubleshooting