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24 HIGH-SPEED INPUT/OUTPUT FUNCTION
24.2 FX3-compatible high-speed counter function
Operation example
The operation of LC35 in the programming example described above is as shown below.
The elements of the composition of the LC device
Each element that composes the LC device is shown below.
The comparison between the UDCNTF instruction and HIOEN/
DHIOEN instruction
The comparison between the UDCNTF instruction and the HIOEN/DHIOEN instruction is described below.
The availability of use when the FX3 compatibility function is enable/disable
: Use
: Not use
The LC device can be used as a high-speed counter only when the FX3 compatible function is valid. However,
this is only the LC device that is set up with parameter. Also, it is possible to use the HIOEN/DHIOEN
instruction.
Item Description
Counting coil This is the activation contact to start the counting of the LC device. When the UDCNTF instruction is turned OFF/ON, the
status turns ON and the counting of the input signal becomes possible.
Setting value This is K specified with UDCNTF LC K. An indirect specification is acceptable.
Current value This is the current value of the counter. The value increases or decreases depending on the input pulse.
Counter contact This turns ON when the current value of the LC device changes from a value less than the setting value to the setting
value or higher. This can be used as LD LC.
Reset coil This turns ON when the RST instruction with the LC device specified turns OFF→ON, and turns OFF when the RST
instruction turns ON→OFF. When the reset coil is ON, the counting is not executed even if the count coil is ON, and the
current value is always 0.
FX3-compatible function enable/disable UDCNTF instruction HIOEN/DHIOEN instruction
Disable
Enable
SM4580
Count direction
Up-count Up-countDown-count
00 0
-1 -1
-2 -2
-3 -3
-4 -4
-5 -5
-6 -6
-7 -7
-8
11
22
33
44
5
X0 Pulse input
LC35 Current value
LC35 Count contact
= Y1
When output has operated
OFF
ON
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