Mitsubishi FX3G Series Programming Manual page 115

FX /FX /FX /FX
3G 3U 3GC 3UC
Programming Manual - Basic & Applied Instruction Edition
2) When special analog adapters and FX
Counter type
Following
software
Software counter with
counter HSCS, HSCR,
HSZ or HSCT
instruction
C241,
C242, C235, C236,
C243, C237, C238,
1-phase
C244, C239, C240
1-counting input
C245
C244(OP),
−
C245(OP)
C247,
C246,
1-phase
C248,
2-counting input
C248(OP)
C249, C250
1 edge
2-
count
C252,
phase
C253(OP),
2-
C251, C253
count-
C254,
4 edge
ing
count C255
input
*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.
*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
Series special function blocks/units.
Used high-speed counter No.
C237
C241
C253(OP)
[4 edge count]
1) The total frequency is calculated as follows because HSZ instruction is used 6 times:
Total frequency
2) The sum of the response frequencies of the high-speed counters
being used is calculated as follows:
"30 kHz × 1[C237]" + "20 kHz × 1[C241]" + "4kHz × 4[C253(OP)]" = 66 kHz ≤ 71 kHz
Series
/FX
3U
Response frequency and total frequency according to instruction use condition
When HSZ and HSCT
Magnifica-
instructions are not
tion for
used
calculating
total Maximum
frequency response
frequency
*1
(kHz)
×1
30
×1
10
×1
30
×1
30
×4
7.5
Input
frequency
Operates as
30 kHz
software counter
20 kHz
Software counter
4 kHz
= 80 − 1.5 × 6 = 71 kHz
4.7 High-Speed Counter [C] (FX3U/FX3UC PLC)
Series special function blocks/units are used
3UC
When only HSCT
instruction is used
Maximum Maximum
Total Total
response
frequency frequency
frequency frequency
(kHz) (kHz)
(kHz)
25
30 - (Num-
10
60 50
25
25
(30-Num-
6.2
Maximum response frequency
calculation
40 − 6 (times) = 34 kHz
40 − 6(times) = 34 kHz
{40 − 6(times)} ÷ 4 = 8.5 kHz
4 Devices in Detail
When only HSZ When both HSZ and HSCT
instruction is used instructions are used
Maximum
Total
response response
frequency
frequency
(kHz)
(kHz) (kHz)
25-(Number
ber of
of instruc-
50−
instruc-
*2
tion)
1.5×(Num
*2
tion)
ber of
instruc-
tion)
(25-Number
ber of
of instruc-
instruc-
tion) ÷ 4
tion) ÷ 4
Magnification for
calculating total
instruction
frequency
× 1
× 1 instruction × 6
× 4
1
Total
2
frequency
(kHz)
3
50−
1.5×(Num
ber of
instruc-
tion)
4
5
6
/FX
3U 3UC
Used
7
HSZ
times
8
9
10
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