7 Applied Instructions
7.26 High Speed Processing 2
756
FXCPU Structured Programming Manual
(Basic & Applied Instruction)
2. Related devices
Cautions
1) This instruction can be executed only once in a program.
If this instruction is programmed two or more times, an operation error is caused by the second instruction
and later, and the instruction will not be executed.
2) This instruction constructs the data table at the END instruction after the first execution of the instruction.
Accordingly, the operation output works after the second scan and later.
3) With regard to DHSCT, DHSCS, DHSCR and DHSZ instructions, up to 32 instructions can be executed in
one operation cycle. An operation error is caused by the 33rd instruction and later, and the instruction will
not be executed.
4) If an output (Y) is specified in , the output processing is executed immediately without waiting for the
output refresh executed by END instruction.
When specifying an output (Y), make sure that the least significant digit of the device number is "0".
Examples: Y000, Y010 and Y020
5) When a high speed counter specified in is indexed with index, all high speed counters are handled
as software counters.
6) For this instruction, only one comparison point (one line) is handled as the comparison target at one time.
Processing will not move to the next comparison point until the current counter value becomes equivalent
to the comparison point currently selected as the comparison target.
If the current value of a high speed counter executes up counting using the comparison data table shown
in the operation example on the previous page, be sure to execute the instruction while the current value
of the high speed counter is smaller than the comparison value in comparison point No. 1.
7) When handling 32-bit data in a structured program, a 16-bit device cannot be specified directly as in the
case of a simple project. Use a label to handle 32-bit data.
A 32-bit counter can be specified directly as it is a 32-bit long device.
Use a global label to specify a device.
8) When this instruction operates in the FX
3U and FX3UC PLCs, the hardware counters (C235, C236, C237,
C238, C239, C240, C244(OP), C245(OP), C246, C248(OP), C251 and C253) switches automatically to
software counters, and the maximum frequency and total frequency are affected.
9) Some restrictions to applicable devices
S1: Only high speed counters C235 to C255 are available for use.
Error
An operation error occurs in the following cases. The error flag M8067 turns ON, and the error code is stored
in D8067.
1) When any devices other than high speed counters C235 to C255 are specified in .
(Error code: K6706)
2) When the "3m-1"th device from a device specified in exceeds the last number of the device.
(Error code: K6706)
3) When the "n"th device from a device specified in exceeds the last number of the device.
(Error code: K6706)
4) When this instruction is used two or more times in a program. (Error code: K6705)
5) With regard to DHSCT, DHSCS, DHSCR and DHSZ instructions, up to 32 instructions can be executed in
one operation cycle. An operation error is caused by the 33rd instruction and later, and the instruction will
not be executed. (Error code: K6705)
Device Name Description
M8138 DHSCT Instruction execution complete flag Turns ON when the operation for the final table No. "m-1" is completed.
D8138 DHSCT Table counter Stores the comparison point number handled as the comparison target.
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