FX3U Series Programmable Controllers
User’s Manual - Hardware Edition
195
11 Use of High-speed Counters (C235 to C255)
11.9 Calculation of Response Frequency and Overall Frequency
11
High-Speed
Counters
12
Output Wiring
13
Wiring for
Various Uses
14
Test Run,
Maintenance,
Troubleshooting
15
IInput/Output
Powered
Extension Units
16
Input/Output
Extension
Blocks
17
Extension
Power Supply
Unit
18
Other Extension
Units and
Options
19
Display Module
20
Terminal Block
11.9 Calculation of Response Frequency and Overall Frequency
11.9.1 Response frequencies of hardware counters
The maximum response frequencies of the hardware counters are shown in the following table.
Depending on the working conditions, the maximum response frequencies of hardware counters are the
same as those of the software counters, and limitations on overall frequency are set up.
→ For the conditions under which the hardware counters are handled as software counters,
refer to the previous page.
11.9.2 Response frequencies and overall frequency of software counters
The maximum response frequencies and overall frequency of software counters are shown below.
When HSZ or HSCT instruction is used in the program, limitations are put on the maximum response
frequencies and overall frequency of all software counters regardless of the instruction operand.
When examining the system or creating the program, use the counters within the maximum response
frequency and overall frequency ranges suitable to the conditions in consideration of the limitations.
1. When FX3U Series special function units/blocks and analog special adapters are not used
Examples of calculation are given in the heavy-line frame.
*1. When an index register is added to a counter number specified by HSCS, HSCR, HSZ or HSCT
instruction, all hardware counters are switched to software counters.
*2. The high-speed counters C244(OP) and C245(OP) cannot count signals of 10kHz or more.
Counter type Counter Nos.
Max. response frequency
Main unit FX3U-4HSX-ADP
1-phase 1-count input
C235,C236,C237,C238,C239,C240 100kHz
200kHzC244(OP),C245(OP) 10kHz
1-phase 2-count input C246,C248(OP) 100kHz
2-phase 2-count
input
1 edge count
C251,C253
50kHz 100kHz
4 edge count 50kHz 100kHz
Counter type
Counter
Nos.
Software
counters
with
HSCS,
HSCR,
HSZ or
HSCT
instruc-
tion
*1
Magni-
fication
for
calcu-
lation
of
overall
frequ-
ency
Response frequency and overall frequency depending
on conditions of instruction to be used
Neither HSZ nor
HSCT instruction
Only HSCT
instruction
Only HSZ instruction
Both HSZ and HSCT
instructions
Max.
response
frequency
(kHz)
Overall
frequency
(kHz)
Max.
response
frequency
(kHz)
Overall
frequency
(kHz)
Max.
response
frequency
(kHz)
Overall
frequency
(kHz)
Max.
response
frequency
(kHz)
Overall
frequency
(kHz)
1-phase
1-count input
C241,
C242,
C243,
C244,
C245
C235,
C236,
C237,
C238,
C239,
C240
×1
40
80
30
60
40 -
(number of
instruc-
tion)
*2
80 - 1.5
×
(number of
instruc-
tion)
30 -
(number of
instruc-
tion)
*2
60 - 1.5
×
(number of
instruc-
tion)
−
C244(OP),
C245(OP)
×1
10 10
1-phase
2-count input
C247,
C248,
C249,
C250
C246,
C248(OP)
×1
40 30
2-
phase
2-
count
input
1 edge
count
C252,
C253
(OP),
C254,
C255
C251,
C253
×1
40 30
4 edge
count
×4
10 7.5
(40 -
number of
instruc-
tion) / 4
(30 -
number of
instruc-
tion) / 4