Response Frequency Of High-Speed Counters - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
4.7.10

Response frequency of high-speed counters

1. Response frequency of hardware counters
The table below shows the maximum response frequency of hardware counters.
When hardware counters are handled as software counters in some operating conditions, their maximum response
frequency becomes equivalent to that of software counters, and thus hardware counters are some times subject to
restrictions in total frequency.
Counter type
1-phase 1-counting input
1-phase 2-counting input
2-phase 2-counting
input
2. Response frequency and total frequency of software counters
The table below shows the maximum response frequency and total frequency of software counters.
When using the HSZ or HSCT instruction in a program, both the maximum response frequency and the total frequency
are limited for all software counters without regarding the operands of the instruction. When examining a system or
creating a program, consider the limitations, and use software counters within the allowable range of maximum
response frequency and total frequency.
1) When special analog adapters and FX
Following
software
counter with
Software
Counter type
HSCS, HSCR,
counter
HSZ or HSCT
instruction
C241,
C242, C235, C236,
C243, C237, C238,
1-phase
C244, C239, C240
1-counting
C245
input
C244(OP),
−
C245(OP)
1-phase C247,
C246,
2-counting C248,
C248(OP)
input C249, C250
1 edge
2-
count C252,
phase
C253(OP),
2-
C251, C253
count-
C254,
4 edge
ing
C255
count
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.
→ For the conditions in which hardware counters are handled as software counters,
C235, C236, C237, C238, C239, C240
C244(OP), C245(OP)
C246, C248(OP)
1 edge count
C251, C253
4 edge count
→ For the conditions handled as software counters, refer to the previous page.
/FX Series special function blocks/units are not used
3U 3UC
Response frequency and total frequency according to instructions used
When HSZ and HSCT
Magnifica-
instructions are not
tion for
used
calculating
total Maximum
Total
frequency response
frequency
frequency
*1
(kHz)
(kHz)
×1
40
×1
10
80
×1
40
×1
40
×4
10
4.7 High-Speed Counter [C] (FX3U/FX3UC PLC)
Counter No.
When only HSCT When only HSZ
instruction is used instruction is used
Maximum Maximum
Total
response response
frequency
frequency frequency
(kHz)
(kHz) (kHz)
30
40 - (Num-
ber of
10
instruc-
*2
tion)
60
30
30
(40-Num-
ber of
7.5
instruc-
tion) ÷ 4
4 Devices in Detail
refer to the previous page.
Maximum response frequency
Main unit FX -4HSX-ADP
3U
100 kHz
10 kHz 200 kHz
100 kHz
50 kHz 100 kHz
50 kHz 100 kHz
When both HSZ and HSCT
instructions are used
Maximum
Total Total
response
frequency frequency
frequency
(kHz) (kHz)
(kHz)
30-(Number
of instruc-
80− 60−
*2
tion)
1.5×(Num 1.5×(Num
ber of ber of
instruc- instruc-
tion) tion)
(30-Number
of instruc-
tion) ÷ 4
113
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