FX Series Programmable Controllers | STL Programming 3 |
3.6Restrictions Of Some Instructions When Used With STL
Although STL can operate with most basic and applied instructions there are a few exceptions. As a general rule STL and
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Branch- | Output |
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processing |
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ing and |
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merging |
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states | Transfer | STL | STL |
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Restrictions on using applied instructions
•Most applied instructions can be used within STL programs. Attention must be paid to the way STL isolates each
Other restrictions are as follows:
-FOR - NEXT structures can not contain STL program blocks.
-Subroutines and interrupts can not contain STL program blocks.
-STL program blocks can not be written after an FEND instruction.
-FOR - NEXT instructions are allowed within an STL program with a nesting of up to 4 levels.
For more details please see the operational compatibility listed in the two tables on pages
Using ‘jump’ operations with STL
• Although it is possible to use the program jump operations (CJ instruction) within STL program flows, this causes additional and often unnecessary program flow complications. To ensure easy maintenance and quick error finding it is recommended that users do not write jump instructions into their STL programs.