Mitsubishi FX3U Series Programming Manual page 339

FX /FX Series Programmable Controllers
3U 3UC
Programming Manual - Basic & Applied Instruction Edition
2) Cases to select a general-purpose comparison instruction
- When the required frequency is beyond the counting performance of software counters
- When counting is regarded important, but the effect of the scan time can be ignored in operations
according to the counting result
- When the number of an instruction is more than 32
M8000
FNC226
LD <
FNC230
LD >=
FNC225
LD >
M8000
2. Device specification range
Only high speed counters (C235 to C255) can be specified as
3. Only 32-bit operation instructions are available.
Because instructions for high speed counters are dedicated to 32 bits, make sure to input "DHSZ (FNC 55)".
4. Caution on values set in the comparison value 1
Make sure that
If is larger than
S
1
5. Relationship between the comparison timing and the result output
1) DHSZ instruction executes comparison and outputs the result only when a counting pulse is input to a
high speed counter.
(When
S
1
C235 changes from "999" to "1000" or from "1999" to "2000".)
2) Because the comparison result cannot be obtained when restoring the power or when the PLC mode
switches from STOP to RUN, the result is not output even if the comparison condition is provided.
→ For the details, refer to "13.6.1 Program in which comparison result is set to ON when power is
6. Priority order in operation among HSCS (FNC 53), HSCR (FNC 54), and HSZ (FNC 55)
instructions for a same high speed counter
→ For the details, refer to "6. Priority order in operation among HSCS (FNC 53), HSCR (FNC 54), and
7. Reset operation by an external terminal
→ For the details, refer to "5. Reset operation by an external terminal [M8025*1: HSC (external reset)
8. Number of occupied devices
1) The comparison value occupies two devices from
2) The output occupies three devices from
DHCMOV
K10000 D100
FNC237
K10000 D100 AND <= K20000
K20000 D100
is smaller than or equivalent to
S
1
, an error is caused.
S
2
is "1000" and is "1999", the output
S
2
HSZ (FNC 55) instructions for a same high speed counter" in Subsection 13.4.1.
13 High Speed Processing – FNC 50 to FNC 59
13.6 FNC 55 – HSZ / High Speed Counter Zone Compare
C251 D100 K0
Y010
D100
Y011
Y012
FNC 50
Y010 K8
REF
.
S
and comparison value 2
S
1
.
S
2
is set to ON as soon as the current value of
D
turned ON [ZCP (FNC 11) instruction]".
or respectively.
S S
1 2
.
D
S
2
mode]" in Subsection 13.4.1.
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