Pulse counter missing counts....a cable length issue?

[mminehan]

I am using the pulse counters (CH 3 & 4) connected to reed switches to count water and gas meters. These are simple rotary magnetic meters with official (manufacture made) switches.

The problem is the GEM seems to be reading low values, as if it is missing some of the pulses. Prior to using a GEM I used the 1-wire counter board which worked very well and did not miss any pulses. But the counter board was located a few meters away from the actual meter. The GEM is inside the house about 10 meters from the gas meter and about 40 meters from the water meter.

The reed switches are connected by outdoor rated CAT5e cable to the GEM.

Is there a limit to the length of the cable? Is there some way to diagnose the problem? Maybe total resistance of the counter circuit (cable & reed switch)?

Thanks, Marty.