Publication 1756-UM523F-EN-P - December 2006
86 Configure and Program the Controller
Use UID and UIE Instruction Pairs
Bound critical rungs with UID and UIE instruction pairs. This prevents
the higher priority task form interrupting the scan-dependent logic.
Buffer Critical Data
This example shows the use of a buffer together with a BSL
instruction.
1. The COP instruction moves the data into a buffer array.
2. The BSL instruction uses the data in the buffer. If a switchover
occurs, the source data (array tag) remains unaffected.
3. The CPS instruction updates array tag. Since higher priority
tasks cannot interrupt a CPS instruction, the instruction keeps
the integrity of the data.
1. 2. 3.
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