DAQStation Rate of Change Math Logic
Example is for a 1 hour Rate of Change
Inputs
Channel 001 is type ~TC – Type E – SPAN – 0. 0 to 100.0 ~ Degree F
Math channels
101 = 001*K01
This channel has the rolling average performed on it so we multiple the value
from channel 001 times the total number of samples. This removes the Average
function from the Rolling Average. It is now just a rolling buffer.
102 = [103.LT.K01?K02:(101-PRE(101))]
If> Then>Else statement. It will display ZERO until the counter has reached the
buffer full number. Then once the buffer is full it will display the rate of change.
103 = [103.EQ.K01?103:103+K03]
Counter. Used to skip until the buffer is full
Rolling Average
101 = ON
Interval = 5s
Number of Samples = 720
102 = ON
Interval = 5s
Number of Samples = 1
103 = ON
Interval = 5s
Number of Samples = 1
Constants
K01 = 720
K02 = 0
K03 = 1
Note: The maximum Number of Samples for the Rolling Average is 1500. You need to
adjust between the Interval Time and Number of Samples to reach the time needed for
the rate of change. The channels 102 and 103 MUST HAVE THE SAME INTERVAL
TIME as the Interval used in channel 101 but the Number of Samples for 102 and 103
will always be 1. We are syncing the sample rate with 101.
Other examples are:
24 hour rate of change = Interval 1 minute and Number of Samples is 1440
15 minute rate of change = Interval 1 second and Number of Samples is 900