181
FNC
53
1
2
M
3
○○○○
D H S C S
S1
S2
D
X Y M S
D.b R.b
KnX KnY
KnM KnS
T C
D,R
V,Z
UnG
K,H
E
" $"
S1
D
S2
S1 : the set value of comparison
S2 : the ID No. of the software high speed counter to be used
D : the destination of the comparison result output
The action of the external output Y0 will be affected to the PLC's Scan
Time. Therefore, its response is slower.
The instruction is by the function of interrupt so the status of Y0 is
immediately output to external output, regardless of the PLC Scan Time.
Please notice that: There is still an output delay from the relay or
transistor output component.
The DHSCS instruction is used to give an immediate output that is by way of a Softwear High Speed Counter
(SHSC). The SHSC receives a pulse stream from corresponding external input and counts by using the interrupt
function (for more details about the SHSC, please refer to the section “2-7 Software High Speed Counter”).
When a SHSC is selected by the DHSCS instruction’s and the present value of the SHSC changes
(increased/decreased by “1”) by the input, the DHSCS instruction will immediately perform the “Compare”
operation. If the present value of the SHSC is equal to the set value of comparison , the status of result output
will turn “ON”. After that, the remains the same status (“ON”) even the comparison is not equal.
Generally, the in this instruction is designed to an output point Y. When the output point Y is designated, the
status “ON” will be carried out immediately to the output component Y.
As the example above, the DHSCS will be enabled if X20=“ON”. When the present value of C235 changes from
199 to 200 or from 201 to 200, the status of Y0 becomes “ON” and immediately sent it to the external output point,
then the Y0 will remain its “ON” status.
K200
C235
Y0
M9000
C235
K5000
DHSCS K200 C235 Y0
C235
M9000
Note
Common Output V.S. DHSCS Instruction Output
DHSCS K200 C235 Y0
X20
S1
S2
D
DD
S2
S1
Operand
Devices
Software High Speed Counter Set
S2 = C235~C255
If D designates to Y, should use Y0~Y7
D can also designate to IHC0~IHC7
D
This instruction is a 32-bit instruction; the DHSCR should be always entered when uses this instruction.
There is no limitation on the number of using times about the DHSCS, DHSCR and DHSZ instructions, while
the DHSCT can only be used once in the program. However, the total of these instructions performed at the
same time should not exceed “8”.
Both the Software High Speed Counter and the DHSCS, DHSCR, DHSZ, DHSCT instructions are only
performed to compare when there is an external signal to the input of the counter. The compare action shall
not be performed if the present value of Software High Speed Counter is changed by a transferring
instructions, because there is no counter input signals. Thus, there is not have the compare action, of course
not has the compare output.
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