ISPSoft User Manual 14.2.6.2 Important Points About Qualifying an Action Once an action qualified by S is executed, it will still be executed even if it is qualified by N or P. The execution of the action stops only when the action is qualified by R. If there is an action which is qualified by S, users have to check whether they have to assign R to the action to stop the execution of the action. When STEP_0 is activated, Action0 and Action1 are executed. After control is passed to STEP_1, Action0 and Action1 will still be executed even if they are qualified by N and P respectively. The execution of Action1 will stop after control is passed to STEP_2.
Action0 is never qualified by R, and therefore it will be executed all the time. Except the R qualifier, when assigning a time-related qualifier for an Action, the qualifier can only be used in the SFC instruction once. In other words, if an action is qualified by D, SD, DS, L, or SL, no other qualifiers can be used for the action, except the R qualifier. From the example shown below, we can see that in the STEP_0, the Action0 and Action1 are qualified by D and L respectively. And in the STEP_1, the Action0 and Action1 are qualified by N and R. The usage of Action 0 being assigned with D in the STEP_0 and N in the STEP_1 is wrong and will cause error to occur.
The usage of Action 1 being assigned with Lin the STEP_0 and R in the STEP_1 is correct, since R can be added to an Action with more than 1 qualifier. 14-20