Mitsubishi Electric MELSEC-Q series User Manual page 39

(a) Time average
Digital conversion is performed for the duration of the set time, and a sum of the converted values except the
maximum and minimum values is averaged. The averaged value is stored in the buffer memory.
The number of processing within the duration of the set time varies depending on the set time and sampling
cycle.
Number of
processing
The number of processing is as follows in case of the settings below.
Ex.
Sampling cycle
Set time
380
= 7.6 (times)
50
Conversion is processed seven times to output the average value.
The valid lower limit setting value for a time average is calculated as: "(Minimum 4 times) × (Sampling cycle)".
When the sampling cycle is 50ms/8CH:
Ex.
4 × 50 = 200ms
If the number of processing is less than four due to the set time, the error (error code: 20) occurs and the digital output
value becomes 0.
(b) Count average
Digital conversion is performed the set number of times, and a sum of the converted values except the
maximum and minimum values is averaged. The averaged value is stored in the buffer memory.
The processing time that takes to store the averaged value of count average in the buffer memory varies
depending on the sampling cycle.
Processing time =
The processing time is as follows in case of the settings below.
Ex.
Sampling cycle
Set number of times
20 × 50 = 1000 (ms)  The averaged value is output in each 1000ms.
Since the count average requires a sum of at least two digital conversions besides the maximum and minimum values, the
set number of times must be four or more.
=
Sampling cycle
Item
Figures after the decimal point are omit.
Set number of times
Item
Set time
Setting
50ms/8CH
380ms
Sampling cycle
Setting
50ms/8CH
20 times
CHAPTER 4 FUNCTIONS
37
4