Download C Programmer`s Toolkit for PACSystems User`s Manual, GFK

5
Non-Standard C Library Functions
Non-Standard C Library functions are not supported in the PACSystems C Toolkit.
See appendix B for functions that are not supported.
Entry Point
In the Series 90 C Toolkit, the entry point into the user application was main(). For the
PACSystems C Toolkit, the entry point is GefMain().
C Standalone Programs
C standalone programs are not supported. However, C program applications that do
not rely on the C program scheduling features can be compiled and executed as C
blocks.
Use of Input Parameters as Pointers to Discrete Memory Tables
In the PACSystems C Toolkit if the user application is passed a pointer to one of the
discrete memory tables (%I, %Q etc.), for example as one of the input parameters to
GefMain(),and the pointer is used to write to discrete reference table memory,
overrides and transitions are not taken into account for the write operation. When a
discrete memory write operation occurs via a pointer in the Series 90 PLCs, overrides
and transitions are taken into account.
For the PACSystems C Toolkit, you should use the following function when writing
directly to discrete memory via a pointer if you want overrides and transition bits to be
respected:
T_INT32 PlcMemCopy(void *pDestination, void *pSource, T_DWORD
size);
GFK-2259E
Chapter 5 Conversion Notes and Series 90 Compatibility
5-5