FC 204 PERIOD - Program Dependencies

[roverman]

Hello,

I'm a new user on the forum, but have used the OSCAT library before with some success.

I am having trouble with the PERIOD function, and I am certain it has to do with the calls to other FC's.
I want to integrate the function in an existing project to be able to determine if current date is within a user selected period (downtime during vacation).
The existing program is using some of the FC addresses of the necessary OSCAT FC's. If I run the program in simulation and delete the existing conflicting FC's everything works, but if I try to rename OSCAT FC's and modify block calls in the code it fails, I don't get any errors but it will not identify dates correctly.
If I check PERIOD [FC204], the comments references DAY_OF_YEAR [FC180], YEAR_BEGIN [FC217], YEAR_OF_DATE [FC219], LEAP_OF_DATE [FC193], LEAP_YEAR [FC194]. I can only find block calls to DAY_OF_YEAR and LEAP_OF_DATE.
Further FC's used are DATE_DINT [FC405] and SET_DATE [FC213]

I don't have access to SCL programming tools so I can only see it in STL, perhaps this is a reason for the trouble?
I would like to name these so they are within FC210-217.

If anyone could help I would appreciate it.