Why does Lookout receive wrong count from FP-CTR-500

[mike.oss]

Counter module flashes light count = to field pulse input device. Lookout fieldpoint object follows device count, but occassionally double counts giving wrong results. Is this a hardware problem with the counter module? A second counter in the system works as expected. Both are wired the same way and read the same way in the software and are receiving signals from like field devices.

[Aaron_G]

Mike,

To rule out the possibility of this being a hardware problem in the FP-CTR-500 module, you can swap both of your FP-CTR-500 modules. I suspect that the problem will remain on the same signal/channel indicating that it is most likely a signal problem.

You may be receiving a double count as a result of noise or signal differences in the sensors wired to the various channels. To reduce the likelihood of a spurious signal causing a double count, you can enable the low pass filter on the FP-CTR-500 to reject signals above 200 Hz. If you look at the signal on a scope, you may see that it is fairly noisy and could use some filtering. Also, consider if one sensor has a longer cable run then the other or if it routes near something that may be electricall
y noisy.

Regards,
Aaron

[mike.oss]

Thanks. As with all good answers, this is simple and straightforward. Your help is greatly appreciated.

Regards,
Mike