How To Use 2-Phase 2-Count Input Counters C251 To C255 With 4 Edge Counting - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4.7.8 How to use 2-phase 2-count input counters C251 to C255 with
4 edge counting
For the 2-phase 2-count input counters C251 to C255, the edge count is usually set to 1. By using the
programs shown in the table below, the edge count may be set to 4.
Counter No.
C251
C252
C253
C253(OP)
C254
C255
When using 2-phase 2-count input counters with 4 edge
counting
M8000
M8000
M8000
M8000
M8388
M8000
M8000
4.7 High Speed Counter [C] (FX3U/FX3UC PLC)
M8198
C251
K
M8198
C252
K
M8199
C253
K
M8199
M8392
C253
K
M8198
C254
K
M8199
C255
K
4 Devices in Detail
Description
1 edge count (before change)
A phase
+1 +1
B phase
Up-counting
A phase
−1 −1
B phase
Down-counting
↓
4 edge count (after change)
+1 +1 +1 +1 +1
A phase
B phase
+1 +1 +1 +1
Up-counting
−1 −1 −1 −1 −1
A phase
B phase
−1 −1 −1 −1
Down-counting
1
2
3
4
5
6
7
8
9
10
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