When troubleshooting RPM logging problems what are the most common reasons for malfunctioning?
- pickup 800-OP-MAG
- cable 800-OP-CABLE
- logger itself?

Our symptoms are: in logs we see RMP going wildly up and down. Sometimes it seems to be correct. Other channel is dead.
I understand that a dead channel lives in darkness, but the other one: how is it possible that revs go suddenly up - would a light leak into optical cable cause that or is the logger itself in suspect?

Next time we are able to fire up after 2 weeks so what kind of tests we can perform before D-day?

Is there a procedure to test pickups?
I was thinking of building a pulse generator to output a lookalike pulse to test pickups. What kind of current and voltage is needed? How about waveform?