Input Filter Adjustment [D8020]([D8021]); [Device & Common] - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
4.2.9

Input filter adjustment [D8020]([D8021])

1. In FX /FX /FX
3S 3G
Inputs X000 to X017
determined by the value in the range from 0 to 60
D8020 is automatically set to "10 (ms)" when the PLC is powered ON from OFF.
Input terminal Filter
X000 0ms
1ms
10ms
*1
X017
60ms
*1. X000 to X007 in FX
*2. 0 to 15 in FX
1) Program example for adjusting the input filter
When the program shown below is executed, the filter constant is changed to "0 ms".
Because the C-R filter is provided in the hardware, however, the filter constant actually becomes the
value shown in the table below when "0" is specified.
M8000
RUN monitor
FX /FX PLCs
3U 3UC
Input number
X000 to X005
X006, X007
*2
X010 to X017
FX /FX PLCs
3G 3GC
Input number
X000, X001, X003, X004
X002, X005, X006, X007
FX PLC
3S
Input number
X000, X001
X002 to X007
X010 to X017
When setting the input filter to "5 μs" or when receiving pulses whose response frequency is 50 to 100
*1.
kHz using a high speed counter, perform the following:
- Set the wiring length to 5 m or less.
- Connect a bleeder resistor (1.5 kΩ, 1/2 W) to the input terminal. Make sure that the load current of the open collector
transistor output in the counterpart equipment added by the input current of the PLC is 20 mA or more.
*2. In the FX
function.
• The input filter value can be changed as many times as needed in the middle of a program.
• The input filter adjustment described here is not necessary when high speed counters, input interrupts or
pulse catch relays (M8170 to M8177) are used.
4.2 Supplement of Special Devices (M8000 and later and D8000 and later)
/FX /FX PLCs
3GC 3U 3UC
*1
have a digital filter circuit of 0 to 60 ms respectively. The digital filter constant is
0
1
Determined by the value stored in D8020 (Initial value: 10).
10
Input refresh
Image
60
memory
PLC
3G
FX and FX PLCs
3S, 3G 3GC
MOV
EN ENO
s d
K0 D8020
Input filter value when "0" is set
Input filter value when "0" is set
Input filter value when "0" is set
/FX PLCs (16-point type), only X000 to X007 support the input filter adjustment
3U 3UC
4 Operations of Special Devices (M8000 and later, D8000 and later)
*2
stored in the special data register D8020.
*1
5μs
50μs
200μs
10μs
50μs
10μs
50μs
200μs
1
2
3
4
5
6
7
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