Mitsubishi Electric MELSEC FX3U Programming Manual page 387

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Output pulse characteristics
Output pulse
frequency (Hz)
500
300
200
100
0
0 20
1) Write prescribed data in advance to data registers constructing the table as shown in this program
example.
2) The output frequency of the PLSY instruction remains in the value (D303, D302) until the current value of
a high speed counter specified in
16 bits. D303 specifies high-order 16 bits, but is always "0".)
3) The operation in the 2nd line is started after that, and then the operation in each line is executed in turn.
4) When the operation in the last line is completed, the complete flag M8133 turns ON. The program
execution returns to the 1st line, and the operation is repeated.
5) For stopping the operation in the last line, set the frequency in the last table to K0.
6) When the command input is set to OFF, the pulse output turns OFF and the table counter D8131 is reset.
7) After DHSZ instruction is first executed, creation of the table is completed at the END instruction. The
DHSZ instruction becomes valid after that.
8) Accordingly, the contact of PLS M10 is used so that the PLSY instruction is executed from the second
scan after the command input has been set to ON.
Data can be written to the table in a program as shown in this example or directly using keys in peripheral
equipment.
1) M8132
This is the special auxiliary relay for declaring the frequency control mode
2) D8132
In the frequency control mode, the frequency set in the table is received by D8132 sequentially according
to the table counter count D8131.
3) D8134 (low-order) and D8135 (high-order)
In the frequency control mode, the comparison data in the table is received sequentially according to the
table counter count.
Cautions
1) DHSZ instruction can be used only once.
2) With regard to the DHSCS (FNC 53), DHSCR (FNC 54), DHSZ (FNC 55) and DHSCT (FNC280)
instructions used for other purposes, up to 32 instructions including the DHSZ instruction can be driven at
one time.
3) Because the table is created when the END instruction is executed, it is necessary to delay execution of
the PLSY (FNC 57) instruction until creation of the table is completed.
4) Do not change the data table while the DHSZ instruction is driven.
5) In the frequency control mode, simultaneous output to Y000 to Y001 is not permitted.
600 700 800
→ Current value of C251
S
13 High Speed Processing – FNC 50 to FNC 59
13.6 FNC 55 – HSZ / High Speed Counter Zone Compare
becomes equivalent to (D301, D300). (D302 specifies low-order
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