328
FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
13 High Speed Processing – FNC 50 to FNC 59
13.4 FNC 53 – HSCS / High Speed Counter Set
Operation
When the current value of the high speed counter C255 changes from "99" to "100" or from "101" to "100",
Y010 is set to ON (output refresh).
Related instructions
The following instructions can be combined with high speed counters:
Cautions
1. Selection of the count comparison method
When HSCS instruction is used, hardware counters (C235, C236, C237, C238, C239, C240, C244 (OP),
C245 (OP), C246, C248 (OP), C251 and C253) are automatically switched to software counters, and the
maximum frequency of each counter and the total frequency are affected.
Refer to the counting operation described below, and select according to the contents of control whether to
use HSCS instruction or general-purpose comparison instruction.
1) Case to select HSCS instruction
- When the output should be given when the counting result becomes equivalent to the comparison value
without regard to the scan time of the PLC
2) Cases to select a general-purpose comparison instruction
- When the required frequency is beyond the counting performance of the software counters
- When counting is regarded as 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
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 "DHSCS (FNC 53)".
4. 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 operations among HSCS (FNC 53), HSCR (FNC 54), and
HSZ (FNC 55) instructions for the same high speed counter" in Subsection 13.4.1.
Instruction
FNC No.
Instruction name
DHSCS
FNC 53
High speed counter set
DHSCR
FNC 54
High speed counter reset
DHSZ
FNC 55
High speed counter zone compare
DHCMOV
FNC189
High speed counter move
DHSCT
FNC280
High speed counter compare with data table
M8000
RUN monitor
C255
K2,147,483,647
FNC 53
DHSCS
K100
C255
Y010
=
K100
C255
Y010
→
Set to ON.
Comparison
value
Comparison
source
Output
destination
M8000
FNC189
DHCMOV
C251
D100
K0
SET
Y010
FNC230
LD>=
K100
D100
FNC 50
REF
Y010
K8
S