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FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
13 High-Speed Processing – FNC 50 to FNC 59
13.2 FNC 51 – REFF / Refresh and Filter Adjust
Cautions
1. Setting the filter time "n"
Set "n" within the range from K0 (H0) to K60 (H3C) [0 to 60 ms].
2. Function of the input filter
A digital filter is built into the inputs X000 to X017. The filter time can be changed in 1 ms units within the range from 0
to 60 ms using applied instructions. When the filter time is set to "0", the input filter value is as follows.
*1. When setting the input filter time to "5 µs", perform the following actions:
- Make sure that the wiring length is 5 m or less.
- Connect a bleeder resistor of 1.5 kΩ (1 W or more) to the input terminal, and make sure that the load
current in the open collector transistor output of the external equipment is 20 mA or more including the
input current of the main unit.
*2. The filter time is fixed to 10 ms for X010 to X017 in 16-point type FX
3U PLCs and 16-point type FX3UC PLCs.
Program example
1. Relationship between the program and the filter time
Input number Input filter value when set to "0"
X000 to X005
5 µs*
1
X006, X007 50 µs
X010 to X017
*2
200 µs
*2
n
X001
X000
END
When X010 is ON
The image memory of X000 to
X017 is refreshed with an input
filter of 1 ms.
The image memory of X000 to X017 is
refreshed with an input filter of 20 ms.
The image memory is refreshed with
the input filter value set in D8020.
Input
processing
Set value of D8020
(Initial value: 10 ms)
1 ms
20ms
Sequence
program
REFF instruction
REFF instruction
END
Output
processing
X010
X000
M8000
FNC 51
REFF
K1
FNC 51
REFF
K20