I'm trying to measure frequency from a flow meters. So far I'm just trying to measure the freq from a function generator, I select a square wave of around 400 Hz and +-10V of amplitude and I connect it to channel 3.
I type "RA1s 3F" and the only result I get is -99999.9. I tried changing the threshold as indicated in the manual but I always the that same wrong result. How could I fix this??? Thanks a lot for your fast reply.