Mitsubishi Electric MELSEC-Q Structured Programming Manual page 92

FXCPU Structured Programming Manual
[Device & Common]
6) In FX /FX
U 2C
The maximum response frequency of high speed counters C235 to C255 is generally as follows (when
the DHSCS and DHSCR instructions are not used or not driven):
Sum of frequency of 1-phase counters + (Sum of frequency of 2-phase counters) × 4 ≤ 20 kHz
maximum
However, the actual maximum response frequency varies depending on used counters and DHSCS,
DHSCR and DHSZ instructions.
The table below shows the maximum response frequency of each counter. Do not exceed the values
shown below.
(Each value indicates the maximum response frequency of one high speed counter.)
Number of 1-
Combination of
phase counters
high speed
driven
counters
simultaneously
Counter No. when up to three 1-phase counters are
1
2
When only 1-
3
phase counters
4
are used
5
6
When one 2-
1
phase counter (1
2
kHz or less) and
one to four 1-
3
phase counters
4
are used
When only 2-
-
phase counters
-
are used
1) The maximum response frequency of counters changes when the DHSCS, DHSCR and DHSZ
instructions are used.
For example, the maximum response frequency of C235 and C237 driven at the same time is 10
kHz (part A), but decreases to 4 kHz (part B) respectively when the DHSCS and DHSCR
instructions are driven at the same time.
2) When the DHSCS, DHSCR and DHSZ instructions are driven at the same time, the maximum
response frequency is equivalent to the maximum response frequency when the DHSZ instruction
is driven.
90
PLCs
Number of 2-
When DHSCS, DHSCR and
phase counters
DHSZ instructions are not
driven
used or not driven
simultaneously
C235, C237,
driven simultaneously→ C238
- 10
- 10[A]
- 6.6
-
-
-
1
1
1
1
1
2
DHSCS, DHSCR
Maximum response frequency of 1-phase counters
C236, C239, C235, C237,
C240 C238
7.0 7.0
3.5 4.0[B]
2.5 2.5
2.5 1.5
2.5 1.5
2.5 1.5
5.0 4.0
4.0 2.0
3.0 2.0
2.0 1.0
Maximum response frequency of 2-phase counters (kHz)
2.0 2.0
2.0 1.5
2 Devices in Detail
2.7 High Speed Counter [C]
When one or two DHSZ
instructions are driven
C236, C239, C235, C237, C236, C239,
C240 C238
5.0 5.0
2.5 2.5
2.0 2.5
1.5
1.5
1.0
3.0
1.0
1.0
1.0
2.0
1.3
C240
4.0
1.5
1.5