Zero Threshold Limits for analog readings with both negative and positive ranges

[rlao]

Is there a way to set up Zero Threshold Limits for analog readings that have a negative minimum? For example, bidirectional flowmeters can log both reverse and forward flows on a -x L/s to +x L/s range.

Zero Threshold simply changes any reading below the threshold limit to 0. Normally this would be fantastic for something like flowmeter readings because you can filter out any insignificant flow readings like 0.001L/s resulting from signal noise when there is legitimately no flow. However, if you specify a 0.01L/s Zero Threshold on a flow reading spanned from -50L/s to +50L/s, then you filter out every single reverse flow reading which is not ideal.

Would there be a way to have Zero Thresholds apply to the absolute value so that a 0.01L/s setting only filters out flows between -0.01L/s to 0.01L/s rather than all readings below +0.01L/s... That would make the feature much more useful in my opinion.

Thanks

[Joel_Weder · Accepted solution]

In the RemoteConnect Object Configuration tool for an analog object, select the Alert Notifications tab. You can set up as many as four high and four low limit setpoints. So for example the 1H setpoint might be 0.1 and the 1L setpoint -0.1. Then configure the Logic Variable Type to be T_SPx70_ADV_ANALOG. Then in Logic Editor you can use the H and L states (e.g. Tank1_Level.H1_LIMIT) to make decisions about how to filter values.