2.7.10 Response Frequency Of High Speed Counters - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]

2.7.10 Response frequency of high speed counters

1. Response frequency of hardware counters
The tables below show 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 they are subject to restriction of the
total frequency.
→ For conditions under which hardware counters are handled as software counters, refer to the
1) In FX /FX
3U
1-phase 1-counting input
1-phase 2-counting input
2-phase 2-counting input
2) In FX /FX
2N
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 tables below show the maximum response frequency and total frequency of software counters.
When the DHSZ or DHSCT instruction is used in a program, both the maximum response frequency and the
total frequency are restricted for all software counters without regard to operands of the instruction.
While examining a system or creating a program, consider the restrictions, and use software counters within
the allowable range of maximum response frequency and total frequency.
→ For conditions under which hardware counters are handled as software counters, refer to the
1) In FX /FX
3U
• When special analog adapters and FX
Counter type
Software
combined with
counter
DHSCS, DHSCR,
DHSZ or DHSCT
instruction
C241, C242, C235, C236,
C243, C244, C237, C238,
1-phase
C245 C239, C240
1-counting
input
C244(OP),
-
C245(OP)
1-phase
C247, C248,
2-counting C246, C248(OP)
C249, C250
input
1-
edge
2-
count-
phase C252,
ing
2- C253(OP),
C251, C253
count- C254,
4-
ing C255
edge
input
count-
ing
*1. When index registers are added to a counter number specified by the DHSCS, DHSCR, DHSZ or
DHSCT instruction, all hardware counters switch to software counters.
*2. High speed counters C244 (OP) and C245 (OP) can count at up to 10 kHz.
84
PLCs
3UC
C235, C236, C237, C238, C239, C240
C244(OP), C245(OP)
C246, C248(OP)
1-edge counting
C251, C253
4-edge counting
PLCs
2NC
C235, C236
C246
C251
PLCs
3UC
When DHSZ and
Following
DHSCT instructions
software
are not used
counter
Maximum
response
frequency
*1
(kHz)
×1
40
×1
10
×1
40
×1
40
×4
10
Counter No.
Counter No.
/ Series special function blocks/units are not connected
3U 3UC
Response frequency and total frequency according to instructions used
When only DHSCT
instruction is used
Maximum
Total Total
response
frequency frequency
frequency
(kHz) (kHz)
(kHz)
30
10
30
80 60
30
7.5
2 Devices in Detail
2.7 High Speed Counter [C]
previous page.
Maximum response frequency
Main unit FX
100kHz
10kHz
100kHz
50kHz
50kHz
Maximum response frequency
Main unit
60kHz
60kHz
30kHz
previous page.
When both DHSZ and
When only DHSZ
DHSCT instructions
instruction is used
Maximum Maximum
Total
response response
frequency
frequency frequency
(kHz)
(kHz) (kHz)
40 - (Num- 30 - (Num-
ber of times ber of times
of using of using
80 - 1.5 ×
instruc- instruc-
(Number of
*2
tions) times of tions)
using
instruc-
tions)
(40 - Num- (30 - Num-
ber of times ber of times
of using of using
instruc- instruc-
tions) / 4 tions) / 4
-4HSX-ADP
3U
200kHz
100kHz
100kHz
are used
Total
frequency
(kHz)
60 - 1.5 ×
(Number
*2
of times of
using
instruc-
tions)