Pulse Counting Problem CTR-500

[cmj]

I am using a couple CTR-500 on a compact fieldpoint setup to measure pulses from 2 energy (BTU) meters, 3 diaphragm gas meters, 2 liquid flow meters and 2 Watt-hour electrical meters.  I seem to have a problem with my pulse counts accelerating upon start up of the program (up to 1000 pulses/15 minutes <- which is unrealistic for the hardware installed and then falling to 5-10 pulses/15minutes <-reasonable value).  The pulse count does not correlate with the manual meter readings I have taken either, with the exception of the Watthour meters.  I am unsure if it is my program, wiring, or peripheral equipment at this point. 

Has anyone seen a problem like this before?  I have included a couple graphs showing the raw pulse count (saved every 15 minutes) and the change in pulse count every 15 minutes.

[Smootastic]

Hi cmj,

How are you reading the CTR-500?  An example VI may help. 

[cmj]

Here is an example vi of how I am reading the pulses and some data processing I am doing with the signal.  I have built in a totalised pulse counter to compensate for the maximum of 65535 pulses that can be counted by the module - so I do not miss pulse counts on reset. 

[Smootastic]

Hi cmj,

Why are you using a FieldPoint Read to get the timestamp?  You should use the Get Date/Time in Seconds VI:

 

Does this help?  I feel like the code you have right now may not make the case structure work correctly. 

[cmj]

I will try out the Get Date/Time in Seconds VI when I get a chance, but the time is only used to save the data (counted pulses) to disk periodically (at 15 minute intervals).  I don't feel this change will help my pulse count problems.  Did you see any problems with the code that is used to actually count the pulses?

[Smootastic · Accepted solution]

Hi cmj,

I need to continue checking your code, but do you have maybe a constant signal you can test the measurements with?  Maybe an extra DAQ card to output a pulse train for testing? 

[cmj]

Found a mistake in my code.  I was resetting a number causing a run away.  Thanks for your help.