Mitsubishi Electronics FX3G 用户手册
127
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)
1
Introdu
ction
2
Ov
ervi
ew
ew
3
Instruction
Li
st
4
D
evices
in Det
ai
l
5
Specifi
ed the
De
vice
&
C
onst
ant
ant
6
Bef
ore
ore
Pr
og
ra
mmi
ng
ng
7
Bas
ic
ic
Instruction
8
FN
C00-FN
C00-FN
C0
9
Program Fl
ow
9
FNC
10-FN
C19
Mov
e & Com
e & Com
pare
10
FNC
20-FNC
29
Arith. & Lo
gi
c
Operati
on
2) When special analog adapters and FX
3U
/FX
3UC
Series special function units/blocks are used
*1.
When an index register is added to a counter number specified by a HSCS, HSCR, HSZ or HSCT instruction,
all hardware counters are switched to software counters.
all hardware counters are switched to software counters.
*2.
The high-speed counters C244 (OP) and C245 (OP) can count up to 10 kHz.
3. Calculation of the total frequency
Total frequency
≥ Sum of "Response frequency of high-speed counter × Magnification for calculating total frequency"
4. Calculation example
When only HSZ instruction is used 6 times in a program, the total frequency and response frequency are calculated as
follows in accordance with the columns for "When only HSZ instruction is used" shown above.
This calculation example is provided for a system configuration not including special analog adapters and FX
follows in accordance with the columns for "When only HSZ instruction is used" shown above.
This calculation example is provided for a system configuration not including special analog adapters and FX
3U
/FX
3UC
Series special function units/blocks.
Counter type
Magnifica-
tion for
calculating
total
frequency
Response frequency and total frequency according to instruction use condition
Software
counter
Following
software
counter with
HSCS, HSCR,
HSZ or HSCT
instruction
*1
When HSZ and HSCT
instructions are not
used
When only HSCT
instruction is used
When only HSZ
instruction is used
When both HSZ and HSCT
instructions are used
Maximum
response
frequency
(kHz)
Total
frequency
(kHz)
Maximum
response
frequency
(kHz)
Total
frequency
(kHz)
Maximum
response
frequency
(kHz)
Total
frequency
(kHz)
Maximum
response
frequency
(kHz)
Total
frequency
(kHz)
1-phase
1-counting input
C241, C242,
C243, C244,
C245
C243, C244,
C245
C235, C236,
C237, C238,
C239, C240
C237, C238,
C239, C240
×1
30
60
25
50
30 - (Num-
ber of
instruc-
tion)
*2
50
−
1.5
×(Num
ber of
instruc-
tion)
25-(Number
of instruc-
tion)
*2
50
−
1.5
×(Num
ber of
instruc-
tion)
−
C244(OP),
C245(OP)
C245(OP)
×1
10
10
1-phase
2-counting input
C247, C248,
C249, C250
C249, C250
C246,
C248(OP)
C248(OP)
×1
30
25
2-
phase
2-
count-
ing
input
1 edge
count
C252,
C253(OP),
C254,
C255
C253(OP),
C254,
C255
C251, C253
×1
30
25
4 edge
count
×4
7.5
6.2
(30-Num-
ber of
instruc-
tion)
÷ 4
(25-Number
of instruc-
tion)
÷ 4
Used high-speed counter No.
Input
frequency
Maximum response frequency
calculation
Magnification for
calculating total
frequency
Used
instruction
C237
Operates as
software counter
software counter
30 kHz
40
− 6 (times) = 34 kHz
× 1
HSZ
instruction
× 6
times
C241
Software counter
20 kHz
40
− 6(times) = 34 kHz
× 1
C253(OP)
[4 edge count]
[4 edge count]
4 kHz
{40
− 6(times)} ÷ 4 = 8.5 kHz
× 4
1) The total frequency is calculated as follows because HSZ instruction is used 6 times:
Total frequency = 80
Total frequency = 80
− 1.5 × 6 = 71 kHz
2) The sum of the response frequencies of the high-speed counters
being used is calculated as follows:
"30 kHz
being used is calculated as follows:
"30 kHz
× 1[C237]" + "20 kHz × 1[C241]" + "4kHz × 4[C253(OP)]" = 66 kHz ≤ 71 kHz