Hi everbody,
I'm working with automatic verifcation of PLC programs written in Ladder language.
Knowing that the real outputs of the PLC are only updated after the execution of all rungs I have the following questions.
If the value of a bit variable V is actualized in Rung N, and the same variable is used as an input in the Rung N+1, which will be the value of V used in Rung N+1 (during the same execution cycle), the old one obtained during the input reading cycle or the new one calculated in Rung N.
I would like to know the answer in both cases, Where V is a input/output variable, and where V is a PLC memory location variable.
I would apreciatte any help.
Darlam Bender
IRIT - ENSEEIHT
I'm working with automatic verifcation of PLC programs written in Ladder language.
Knowing that the real outputs of the PLC are only updated after the execution of all rungs I have the following questions.
If the value of a bit variable V is actualized in Rung N, and the same variable is used as an input in the Rung N+1, which will be the value of V used in Rung N+1 (during the same execution cycle), the old one obtained during the input reading cycle or the new one calculated in Rung N.
I would like to know the answer in both cases, Where V is a input/output variable, and where V is a PLC memory location variable.
I would apreciatte any help.
Darlam Bender
IRIT - ENSEEIHT