Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 81)

Programming Overview
4–5
Program Files
Program files contain controller information, the main ladder program, interrupt
subroutines, and any subroutine programs. These files are:
•
System Program (file 0) – This file contains various system related
information and user-programmed information such as processor type, I/O
configuration, processor file name, and password.
•
Reserved (file 1) – This file is reserved.
•
Main Ladder Program (file 2) – This file contains user-programmed
instructions defining how the controller is to operate.
•
User Error Fault Routine (file 3) – This file is executed when a recoverable
fault occurs.
•
High-Speed Counter Interrupt (file 4) – This file is executed when an HSC
interrupt occurs. It can also be used for a subroutine ladder program.
•
Selectable Timed Interrupt (file 5) – This file is executed when an STI occurs.
It can also be used for a subroutine ladder program.
•
Subroutine Ladder Program (files 6 – 15) – These are used according to
subroutine instructions residing in the main ladder program file or other
subroutine files.
Data Files
Data files contain the status information associated with external I/O and all other
instructions you use in your main and subroutine ladder program files. In addition,
these files store information concerning processor operation. You can also use the
files to store “recipes” and look-up tables if needed.
These files are organized by the type of data they contain. The data file types are:
•
Output (file 0) – This file stores the state of the output terminals for the
controller.
•
Input (file 1) – This file stores the status of the input terminals for the
controller.
•
Status (file 2) – This file stores controller operation information. This file is
useful for troubleshooting controller and program operation.
•
Bit (file 3) – This file is used for internal relay logic storage.
•
Timer (file 4) – This file stores the timer accumulator and preset values and
status bits.
Programming