24.1 ADDRESSING
· To use advanced data functions in a PLC, we must first understand the structure of the data in the PLC memory.
· There are two types of memory used in a PLC-5.
-
Program Files - these are a collection of 1000 slots to store up to 1000 programs. The main program will be stored in program file 2. SFC programs must be in file 1, and file 0 is used for program and password information. All other program files from 3 to 999 can be used for `subroutines'.
-
Data Files - This is where the variable data is stored that the PLC programs operate on. This is quite complicated, so a detailed explanation follows.
