Common Cautions On Using Instructions For High-Speed Counter - Mitsubishi FX3G Series Programming Manual

FX /FX /FX /FX
3G 3U 3GC 3UC
Programming Manual - Basic & Applied Instruction Edition
13.4.1

Common cautions on using instructions for high-speed counter

DHSCS (FNC 53), DHSCR (FNC 54), DHSZ (FNC 55) and DHSCT (FNC280) instructions are provided for high-
speed counters.
This section explains common cautions for these instructions.
1. Limitation in the number of instances of each instruction in a program and number of
instructions driven at the same time
1) FX /FX
3U 3UC
DHSCS, DHSCR and DHSZ instructions can be used as many times as necessary in the same way as general
instructions. However, the number of simultaneously driven instructions is limited. The DHSCT instruction can
only be used once in any program.
Instruction
DHSCS
DHSCR
DHSZ
DHSCT
2) FX /FX
3G 3GC
DHSCS, DHSCR and DHSZ instructions can be used as many times as necessary in the same way as general
instructions. However, the number of simultaneously driven instructions is limited.
Instruction
DHSCS
DHSCR
DHSZ
2. Response frequency of high-speed counters
When the DHSZ or DHSCT instruction is used in FX
frequency of every software counter are limited.
When the DHSCS, DHSCR or DHSZ instruction is used in FX
counters is limited.
→ For the maximum response frequency and total frequency in FX
3. Specification of output numbers (Y)
When using the same instruction for high-speed counter repeatedly or when driving two or more other instructions for
high-speed counter at the same time, specify such output devices (Y) whose high-order two digits are the same (in
units of 8 devices).
1) When using devices of the same number (in units of 8 devices)
Example: When using Y000, specify Y000 to Y007. When using Y010, specify Y010 to Y017.
2) When using two or more instructions for high-speed counter and non-consecutive output (Y) numbers
A program example is shown below:
M8000
When C255 reaches K100, the output Y000 is driven by interrupt. Y010 is driven when END processing is
executed.
If interrupt drive is required, use an output number ranging from Y001 to Y007 whose high-order two digits are
equivalent.
346
Series
PLCs
Limitation in number of instructions driven at same time
32 instructions including DHSCT instruction
Only 1 (This instruction can only be used once.)
PLCs
Limitation in number of instructions driven at same time
6 instructions
→ For the total frequency in FX
FNC 53
K100 C255
DHSCS
FNC 53
K100 C255
DHSCS
13 High-Speed Processing – FNC 50 to FNC 59
13.4 FNC 53 – HSCS / High-Speed Counter Set
/FX PLCs, the maximum response frequency and total
3U 3UC
/FX PLCs, the total frequency of high-speed
3G 3GC
/FX
3U
/FX
3G
Y000
Y010
PLCs, refer to Subsection 4.7.10.
3UC
PLCs, refer to Subsection 4.8.7.
3GC