The security DFB, the implementation of which is identical to that of a DIAG AS-i DFB, can be programmed in any program module (Main, SR or section) in Ladder Diagram (LD), Structured Text (ST), Functional Block (DFB) and Instruction List (IL) languages.
It is:
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It is preferable to run the security DFB in the MAST task (for performance reasons).
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It is strongly recommended to program a security DFB instance only once in the project.
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In order for a security DFB to execute, it is necessary that:
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the DFB is called (the program element to which it is assigned must execute),
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the Enable input is at 1.
Representation:
Programming in ladder diagram
The security DFB function block is inserted in a contacts network. The programming consists of linking these inputs/outputs
Representation:
CAL SAFETY_MONITOR_1 (I0,..., I3, %MW101, Q0,...,Q3, %M102)
Programming in structured text language
The programming syntax is as follows:
%Li: label
SAFETY_MONITOR_1 ( I0,..., I3, %MW101, Q0,...,Q3, %M102);
where:
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%Li: label,
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SAFETY_MONITOR_1: name of instance of a DFB,
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I0,..., I3: DFB inputs,
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%M101: DFB enable input,
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Q0,...,Q3: variable linked with the DFB outputs,
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%M102: Error output variable
WARNING 
