Chapter 4
Data File Organization and Addressing
4–20
Deleting data is accomplished only in the Offline mode. There are two ways
to delete the contents of data files:
•
Clear memory – This deletes your entire program, including all files
except the system program file (0) and the status data file (2).
•
Use the memory map function – The memory map function allows you
to delete data in individual files or portions of files. For example, you can
delete blocks of addresses that have been allocated but are not being used.
Not Used
Not Used
Allocated Space
You cannot delete
these files.
You can delete
these files.
You cannot delete an element if it is used in your program. Neither can you
delete an unused element if a higher numbered element in the file is used in
your program. (For example, if you are using element B3:5, you cannot
delete B3:0 through B3:4, even if you aren’t using them in your program.)
Important: Make certain that you do not inadvertently delete data originally
reserved for indexed addressing. Unexpected operation will
result.
You can enter integer constants directly into many of the instructions you
program. The range of values for most instructions is –32,768 through
+32,767.
Instructions such as SQO, SQC, MEQ, and MVM allow you to enter a hex
mask, which is also a program constant. The hex mask is represented in
hexadecimal, range 0-FFFF.
Program constants are used in place of data file elements. They cannot be
manipulated by the user program. You must enter the offline program editor
to change the value of a constant.
See appendix B in this manual for more information on number systems.
Deleting Data
Program Constants
