GE PACSystems RX7i

Chapter 3. Program Data
56 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
3.10.3 UDT Limits
▪ Maximum number of UDTs per target: 2048
▪ Maximum UDT size: 65,535 bytes
Note: Bit spares created to line up the end of a section of BOOL variables or arrays with the end of
a byte will count toward the maximum size.
▪ Maximum number of top-level UDT elements: 1024
▪ Maximum array size of a top-level UDT element: 1024 array elements
▪ UDTs do not support the following:
- Two-dimensional arrays
- Function block data types
- Enumerated data types
▪ You cannot nest a UDT of one memory type in a UDT of a different memory type.
▪ You cannot alias a variable to a UDT variable or UDT variable element.
▪ A FAULT contact supports a BOOL element of a UDT I/O variable, but not a BOOL element of a
UDT parameter in a UDFB or parameterized block.
▪ POSCON and NEGCON do not support BOOL elements of UDT parameters in parameterized
blocks or UDFBs.
3.10.4 RUN Mode Store of UDTs
An RMS can be performed on a target that contains a variable of a UDT, unless:
▪ An operation in the UDT editor modifies the offset or bit mask of an element that has the same
name before and after the operation.
▪ The size of the UDT definition increases.
▪ Array length increases.
▪ The memory type of the UDT definition changes.
▪ There is a data type change in the UDT definition, except for the following interchangeable data
types:
- WORD, INT, UINT
- DWORD, DINT
▪ The UDT definition is renamed.