What is AFI in PLC programming?
In PLC (Programmable Logic Controller) programming, AFI typically stands for “Always False Instruction.” AFI is a logic instruction used to create a condition that is always false. This instruction can be useful for certain control logic scenarios where you want to ensure that a particular branch of the program is never executed under any circumstances.
In ladder logic programming, for instance, an AFI instruction might be represented by a normally closed contact or a false condition block, depending on the specific PLC programming environment.
By incorporating AFI instructions, programmers can design more robust and reliable control logic by explicitly defining conditions that should never occur. This helps prevent unintended operation of machinery or processes controlled by the PLC.