Omron CP1L-EL20DR-D, Руководство по эксплуатации

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Condition Flags Section 4-14
Using the Condition Flags The Condition Flags are shared by all of the instructions, so their status may
change often in a single cycle. Be sure to read the Condition Flags immedi-
ately after the execution of instruction, preferably in a branch from the same
execution condition.
Since the Condition Flags are shared by all of the instructions, program oper-
ation can be changed from its expected course by interruption of a single task.
Be sure to consider the effects of interrupts when writing the program. Refer
to SECTION 2 Programming of CS/CJ Series Programming Manual (W394)
for more details.
The Condition Flags are cleared when the program switches tasks, so the sta-
tus of a Condition Flag cannot be passed to another task. For example the
status of a flag in task 1 cannot be read in task 2.
Saving and Loading Condition Flag Status
The CP1L-EL/EM CPU Units support instructions to save and load the Condi-
tion Flag status (CCS(282) and CCL(283)). These can be used to access the
status of the Condition Flags at other locations in a task or in a different task.
The following example shows how the Equals Flag is used at a different loca-
tion in the same task.
=
Instruction A
The result from instruction A is
reflected in the Equals Flag.
Instruction B
Instruction
LD
Instruction A
AND
Instruction B
Operand
Condition Flag,
e.g., =
CMP
CCS
CCL
Instruction A
Instruction B
Stores result of comparison in the Condition Flags.
This will enable loading the results to use with
Instruction B.
The result of the comparison instruction in the
Equals Flag can be used by Instruction B without
interference from Instruction A.
Loads the statuses of the Conditions Flags that
were stored.
Saves status of Condition Flags.
Task