Mitsubishi Electronics FX3G User Manual

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FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
 Series
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.8 High-Speed Counter [C] (FX3U/FX3UC PLC)
4.8.8
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.
When using 2-phase 2-count input counters with 4 edge 
counting
Description
C251
1 edge count (before change)
4 edge count (after change)
C252
C253
C253(OP)
C254
C255
M8000
M8198
C251
K{{{
A phase
B phase
+1
+1
Up-counting
A phase
B phase
−1
−1
Down-counting
A phase
B phase
+1
Up-counting
+1 +1 +1 +1
+1 +1 +1 +1
A phase
B phase
−1
Down-counting
−1 −1 −1 −1
−1 −1 −1 −1
M8000
M8198
C252
K{{{
M8000
M8199
C253
K{{{
M8388
M8199
C253
K{{{
M8392
M8000
M8000
M8198
C254
K{{{
M8000
M8199
C255
K{{{