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FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.8 High Speed Counter [C] (FX3G PLCs)
1
Introduction
2
Overview
3
Instruction
List
4
Devices
in Detail
5
Specified the
Device &
Constant
6
Before
Programming
7
Basic
Instruction
8
FNC00-FNC09
Program Flow
9
FNC10-FNC19
Move & Compare
10
FNC20-FNC29
Arith. & Logic
Operation
4.8.2 Input assignment for high speed counters
Inputs X000 to X007 are assigned as shown in the table below according to each high speed counter number.
When a high speed counter is used, the filter constant of a corresponding input number in the main unit automatically
changes (X000, X001, X003 and X004: 10 µs, X002, X005, X006 and X007: 50 µs). Input terminals not used for high
speed counters, however, can be used as general inputs.
→ For the input specifications of the main unit, refer to the Hardware Edition of the main unit.
U: Up-counting input D: Down-counting input A: A phase input
B: B phase input R: External reset input S: External start input
Restriction to overlap input numbers
• Inputs X000 to X007 are used for high speed counters, input interrupt, pulse catch, SPD/ZRN/DSZR instructions
and general-purpose inputs. When assigning functions, there should be no overlap between those input terminals.
For example, when C251 is used, X000 and X001 are occupied. As a result, "C235, C236, C241, C244, C246,
C247, C249, C252 and C254", "input interrupt pointers I000 and I101", "pulse catch contacts M8170 and M8171"
and "SPD, ZRN and DSZR instructions using X000 and/or X001" cannot be used.
Counter No.
Input terminal assignment
X000 X001 X002 X003 X004 X005 X006 X007
1-phase
1-count
input
C235
U/D
C236
U/D
C237
U/D
C238
U/D
C239
U/D
C240
U/D
C241
U/D R
C242
U/D R
C243
U/D R
C244
U/D R S
C245
U/D R S
1-phase
2-count
input
C246
U D
C247
U D R
C248
U D R
C248(OP)
U D
C249
U D R S
C250
U D R S
2-phase
2-count
input
C251
A B
C252
A B R
C253
A B R
C253(OP)
A B
C254
A B R S
C254(OP)
A B
C255
A B R S