I have attached a frequency signal to the counter of a Labjack U12. However, I can not read the frequency neither using Ecount nor the provided example LJcounter. No error message, but no counts, the timer works. I can read a frequency of 6.06 kHertz with a multimeter between CNT and GND. The signal comes from a Seabird conductivity cell, that gets 24V DC current and generates a frequency signal (signal ground is on power ground). I have connected the ground of the 24V power supply to Labjack GND. The voltage I measure between CNT and GND is 0.4V AC on the DVM ( 0.28V in DC mode). I checked with a second U12 to exclude a hardware problem, same result. I wonder if it is not possible to measure frequency with this setup with a U12 at all or did I connect something wrongly?
Any help appreciated