5-35
5 Understanding Programming
CJ2 CPU Unit Software User’s Manual
5-2 Tasks
5
5-2-4 Designing Tasks
Duplicate Refresh Error Cause Flag (A426.15)/Task Number Generating the
Duplicate Refresh Error (A426.00 to 426.11)
Task Number when Program Stopped (A294)
The type of task and the current task number when a task stops execution due to a program error
will be stored as follows:
z Flags Related to All Tasks
Task Error Flag (A295.12)
The Task Error Flag will turn ON if one of the following task errors occurs.
• No cyclic tasks are READY during a cycle.
• The program allocated to a cyclic task (including extra cyclic tasks) does not exist. (This situation
will not occur when using the CX-Programmer.)
• No program is allocated to an activated interrupt task (including extra cyclic tasks).
Task Number When Program Stopped (A294)
The type of task and the current task number when a task stops execution due to a program error
will be stored as follows:
This information makes it easier to determine where the fatal error occurred, and it will be cleared
when the fatal error is cleared. The program address where task operation stopped is stored in A298
(rightmost bits of the program address) and in A299 (leftmost bits of the program address).
A402.13 Interrupt Task Error Description A426.15
A426.00 to
426.11
Interrupt Task
Error
(when Interrupt
Task Error Detec-
tion is enabled in
the PLC Setup)
If Duplicate Refresh Error Detection is enabled in
the PLC Setup, the Duplicate Refresh Error Flag
will turn ON if the following conditions occur for the
same Special I/O Unit.
• There is a conflict between an IORF, FIORF,
IORD, or IOWR instruction executed in the inter-
rupt task and an IORF, FIORF, IORD, or IOWR
instruction executed in the cyclic task.
• There is a conflict between an IORF, FIORF,
IORD, or IOWR instruction executed in the inter-
rupt task and the CPU Unit's I/O refreshing (END
refreshing).
When a Special I/O Unit's Cyclic Refreshing is
enabled in the PLC Setup, and an IORF, FIORF,
IORD, or IOWR instruction is executed for the same
Special I/O Unit, there will be duplicate refreshing
and an Interrupt Task Error will occur.
1 (ON) The unit number
of the Special I/O
Unit being
refreshed will be
stored in 12 bits of
binary data (unit
No. 0 to 95: 000 to
05F Hex).
Type A294
Interrupt task 8000 to 80FF Hex (correspond to interrupt
task numbers 0 to 255)
Cyclic task 0000 to 007F Hex (correspond to task num-
bers 0 to 127)
Type A294
Cyclic task 0000 to 007F Hex (correspond to task num-
bers 0 to 127)
Interrupt task (including
extra cyclic task)
8000 to 80FF Hex (correspond to interrupt
task numbers 0 to 255)
To Next Page
Loading...
Need help?
General