Turning off data interpolation for Ignition Edge-MQTT

Ignition
1

I am having an issue with data interpolation on my charts in ignition. We are using MQTT to transmit data from a remote site back to our site for analysis and with the way MQTT works, it only transmits when data hasn’t changed.

So for example. We have motor KWs that we are transmitting back. A lot of the time those motors are off so but when they kick on the KWs rise dramatically. The way this shows on our charts is the point where the motor turns off, then a steady rise up to the point that the motor turns on the next day. I just want that value to be 0 until it kicks on the next day.

So I guess what I am looking for is for the charts to hold its value if there is no new incoming data. I could probably do it with code but would have to edit every single tag.

Has anyone had this issue before?

2

I think I figured out the solution. I guess I didn’t really understand the differences between Analog and Discrete Values when turning on history.

Discrete means that the values do not interpolate and it stores only if the value is outside the deadband.

Whereas Analog forms a “Corridor” around the deadband when it stores and interpolates the data linearly from one point to another.

I thought originally it was just asking which value that data point is.