Mitsubishi Electric FX3G SERIES Programming Manual page 359

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Related instructions
The following instructions can be combined with high-speed counters:
Instruction
DHSCS
DHSCR
DHSZ
DHCMOV
DHSCT
Cautions
1. Selection of the count comparison method
1) FX /FX PLC
3U 3UC
When the HSCR instruction is used in FX
C240, C244 (OP), C245 (OP), C246, C248 (OP), C251 and C253) are automatically switched to software
counters, and the maximum frequency and total frequency of each counter are affected.
Refer to the counting operation described below, and select according to the contents of control whether to use
HSCR instruction or general-purpose comparison instruction.
a) Case to select DHSCR instruction
- When the output should be given when the counting result becomes equivalent to the comparison value
regardless of the scan time of the PLC
b) Cases to select a general-purpose comparison instruction
- When the frequency is beyond the counting performance of software counters (and below the counting
performance of hardware counters)
- When counting is important, but the effect of the scan time can be ignored in operations depending on the
counting result
- When the number in an instruction is more than 32
M8000
FNC229
LDD<=
M8000
2) FX PLCs
3G
When the HSCR instruction is used in FX
Refer to the counting operation described below, and select according to the contents of control whether to use
the HSCR instruction or a general-purpose comparison instruction.
a) Case to select the HSCR instruction
- When the output should be given if the counting result becomes equivalent to the comparison value
regardless of the scan time of the PLC
b) Cases to select a general-purpose comparison instruction
- When counting is regarded as important, but the effect of the scan time can be ignored in operations
according to the counting result
- When an instruction is used 6 times or more
FNC229
LDD<=
M8000
FNC No.
FNC 53 High-speed counter set
FNC 54 High-speed counter reset
FNC 55 High-speed counter zone compare
FNC189 High-speed counter move
FNC280 High-speed counter compare with data table
/FX
3U
FNC189
C251
DHCMOV
K10000 D100
FNC 50
REF
PLCs, the total frequency of each counter is affected.
3G
K10000 C251
FNC 50
REF
13 High-Speed Processing – FNC 50 to FNC 59
13.5 FNC 54 – HSCR / High-Speed Counter Reset
Instruction name
PLCs, hardware counters (C235, C236, C237, C238, C239,
3UC
D100 K0
RST Y010
Y010 K8
RST Y010
Y010 K8
11
12
13
14
15
16
17
18
19
20
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