4-13 Task Flags; 4-14 Condition Flags - Omron CP1L-EL20DR-D Operation Manual

Task Flags
Precautions

4-13 Task Flags

Task Flag Initialization
Forcing Bit Status

4-14 Condition Flags

Forcing Bit Status
Summary of the Condition
Flags
Data Registers are normally local to each task. For example, DR0 used in
task 1 is different from DR0 used in task 2. (A PLC Setup setting can be made
from the CX-Programmer to share Data Registers between tasks.)
The content of Data Registers cannot be accessed (read or written) from the
CX-Programmer.
Do not use Data Registers until a value has been set in the register. The reg-
ister's operation will be unreliable if they are used without setting their values.
The values in Data Registers are unpredictable at the start of an interrupt
task. When a Data Register will be used in an interrupt task, always set a
value in the Data Register before using the register in that task.
Task Flags range from TK00 to TK31 and correspond to cyclic tasks 0 to 31.
A Task Flag will be ON when the corresponding cyclic task is in executable
(RUN) status and OFF when the cyclic task hasn't been executed (INI) or is in
standby (WAIT) status.
Note These flags indicate the status of cyclic tasks only, they do not reflect the sta-
tus of interrupt tasks.
The Task Flags will be cleared in the following cases, regardless of the status
of the IOM Hold Bit.
1. When the operating mode is changed from PROGRAM mode to
RUN/MONITOR mode or vice-versa
2. When the power is cycled.
The Task Flags cannot be force-set and force-reset.
These flags include the Arithmetic Flags, such as the Error Flag and Equals
Flag, which indicate the results of instruction execution.
The Condition Flags are specified with symbols, such as P_CY and P_ER,
rather than addresses. The status of these flags reflects the results of instruc-
tion execution, but the flags are read-only; they cannot be written directly from
instructions or the CX-Programmer.
Note The CX-Programmer treats condition flags as global symbols beginning with
P_.
All Condition Flags are cleared when the program switches tasks, so the sta-
tus of the ER and AER flags are maintained only in the task in which the error
occurred.
The Condition Flags cannot be force-set and force-reset.
The following table summarizes the functions of the Condition Flags, although
the functions of these flags will vary slightly from instruction to instruction.
Refer to the description of the instruction for complete details on the operation
of the Condition Flags for a particular instruction.
Section 4-13
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