NAiS FP Series, Hardware Manual

Page: 85 / 199

FP0 Hardware Analog I/O Unit
4-18 Matsushita Electric Works (Europe) AG
4.7.2 Averaging for a Thermocouple Range
When the input range is set to a thermocouple (K, J or T type), processing like that
shown below is carried out internally in the analog I/O unit.
Operation
item Time chart
Analog input
value ch0
(thermocouple
input)
4mV (K type thermocouple, 100
°
C)
41mV (K type thermocouple, 1000
°
C)
Reading time
(see note)
ch0
ch1
ch0
ch1
ch0
ch1
ch0
ch1
ch0
ch1
ch0
ch1
ch0
ch1
70m
sec 70m
sec 70m
sec
560msec
1000 1000 1000 100 90 100 100 1000
Internal
processing for
analog I/O unit
ch0
100 100 90
min
100 1000
max
(100+100+100) ÷ 3=100
100 100 1000 1000
max
(100+100+1000) ÷ 3=400
100 1000 1000 1000
max
(100+1000+1000) ÷ 3=700
1000 1000 1000
max
(1000+1000+1000) ÷ 3=1000
90
min
90
min
100
min 1000
Averaging of results from 3 times, with maximum/minimum
values deleted
Digital output
value (WX)
(temperature
°
C)
K1000
K700
K400
K100
560msec
Starting from the most recent data, the data from the last five times is taken. The
maximum and minimum values are deleted, and then averaging is carried out on the
remaining three items. The value obtained from the most recent averaging is normally
used as the value output at this time. (If a fraction results from the calculation, it is
rounded off.)
Note
In the read timing, the minimum and maximum values are
subtracted from the data from the last ten times, just as in
averaging processing on
page 4-17 , and the data from the
remaining eight times is used for the averaging.