Chapter 2 Basic Unit Specification
4. High speed input
2-28
4.4.2
1 Phase 2 input
X012 is ON: C246 will operate up counting when Input
X000 is OFF
Æ
ON, while Down counting when X001 is
OFF
Æ
ON.
X012 is ON: C249 will start to operate up counting for
X001, down counting for X000 when X005 is ON.
When X002 is ON, C249 will be reset at once. Sequential
instruction RST also can do the same as left figure.
C246~C249 counting direction can be supervised by M8235~M8245.
4.5
Application example for 2 phase high speed counter
4.5.1
2 Phase 2 inputs
The present value and output operation of 32 bit counter is same with former 1phase 1input high
speed counting.
z
When X012 ON, C251 starts to count X000 (A phase), and
X001(B phase). When X011 ON, RST instruction reset C251.
z
If the present value is bigger than set value, Y000ON, and if
not, Y002 OFF.
z
When Y003 ON, counting direction is Up, or the direction is
Down.
z
When X012 ON and X006 ON, C254 starts to count X000 (A
phase) and X001 (B phase).
z
When X011 ON, reset C254. And X002 also can do that.
z
If the present value is bigger than set value, Y004 ON.
Otherwise, Y004 will be OFF.
z
Y005 ON: Down counting; Y005 OFF: Up counting.
z
When A phase is ON and B phase is change OFF to ON, the
counting direction will be UP. Otherwise, when B is change
ON to OFF, direction will be down. The state ON/OFF of
M8251~M8255 can indicate the counting direction of C251~C255.
