Introduction
An M580 CPU can execute single-task and multi-task applications. Unlike a single-task application which only executes the MAST task, a multi-task application defines the priorities of each task.
There are four tasks available (see Application Program Structure chapter in Control Expert Program Languages and Structure Reference Manual) and two types of event tasks:
MAST
FAST
AUX0
AUX1
I/O event in a local rack only
timer event in a local rack only
Task Characteristics
The time model, task period, and maximum number of tasks per CPU are defined according to the standalone or Hot Standby CPU reference.
Standalone CPUs:
Task |
Time Model |
Task Period (ms) |
BMEP58 References |
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|---|---|---|---|---|---|---|---|---|---|
Range |
Default Value |
1020 (H) |
20•0 (H) |
30•0 |
40•0 |
5040(C) |
6040(C) |
||
MAST(1.) |
cyclic(2.) or periodic |
1...255 |
20 |
X |
X |
X |
X |
X |
X |
FAST |
periodic |
1...255 |
5 |
X |
X |
X |
X |
X |
X |
AUX0 |
periodic |
10...2550 by 10 |
100 |
X |
X |
X |
X |
X |
X |
AUX1 |
periodic |
10...2550 by 10 |
200 |
X |
X |
X |
X |
X |
X |
1. MAST task is mandatory. 2. When set to cyclic mode, the minimum cycle time is 8 ms if there is a RIO network and 1 ms if there is no RIO network in the system. X This task is supported. |
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Hot Standby CPUs:
Task |
Time Model |
Task Period (ms) |
CPU Reference (BMEH58 ... |
|||
|---|---|---|---|---|---|---|
Range |
Default Value |
2040(C) |
4040(C) |
6040(C) |
||
MAST(1.) |
periodic(2.) |
1...255 |
20 |
X |
X |
X |
FAST(3.) |
periodic |
1...255 |
5 |
X |
X |
X |
AUX0(4.) |
— |
— |
— |
— |
— |
— |
AUX1(4.) |
— |
— |
— |
— |
— |
— |
1. MAST task is mandatory. 2. Only periodic is supported; cyclic is not supported. 3. Supported for (e)X80 ERIO drops. 4. Not supported. X This task is supported. |
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