6. Function blocks
6.1 Manufacturer function blocks
Temperature averaging example
–––
Arithm. Mean
value
–––Continuous
operation
(EMA)
–––One-time
mode
(CMA)
–––
Temp
Fig. 181: Sample curve for hourly temperature measurement, over 7 days
One-time mode
In the example, the average value in one-time mode is calculated for the 24th value /
CMA (23) as follows:
CMA(23) = ROUND [ CMA(22) + I1(23) – CMA(22) ]
23 + 1
CMA(23) = ROUND [ 1889 + (2004 - 1889)/24 ] = ROUND [1893,792] = 1894
Continuous operation
The smoothing factor in the example is SF = 2/(24+1) = 0.08.
In the example, the average value in continuous mode is calculated for the 24th
value:
EMA(23) = ROUND [ EMA(22)+0,08*( I1(23) – EMA(22) ]
EMA(23) = ROUND [ 2035 + 0,08* (2004 – 2035) ]
EMA(23) = ROUND [2032,52 ] = 2033
346
easyE402/24 MN050009ENEaton.com