Installation manual

Publication 1747-RM001G-EN-P - November 2008
Memory Usage C-19
Estimating Total Memory Usage of Your System Using an SLC
5/03, SLC 5/04, or SLC 5/05 Processor
__________ 1. Add the total number of data file words used (excluding the status file and I/O data words) and
enter the result.
__________ 2. Multiply the total number of I/O data words by 3 and enter the result.
__________ 3. Multiply the total number of I/O slots, used or unused, by 3 and enter the result.
__________ 4. To account for processor overhead, enter 236.
__________ 5. Multiply the highest numbered program file used by 5 and enter the result.
__________ 6. Multiply the highest numbered program file used by 5 and enter the result.
Subtotal: __________ 7. Add steps 1 through 6. Enter this as the subtotal (additional 4K word usage).
4096
- (step 7 value)
__________
8. Subtract the value in step 7 from 4096; if the result is positive, enter 12,288 in step 14. If the
result is negative, subtract the absolute value from 12,288 and enter the result in step 14. (This
decreases the value.)
__________ 9. Calculate the total number of words used by the instructions in your program and enter the result.
Refer to Table C.5 on page C-13.
__________ 10. Add the total number of rungs (1 word per rung) and enter the result.
__________ 11. Add 1 word for each indexed address reference and enter the result.
__________ 12. Add 2 words per rung for each rung that contains an indexed address reference and enter the
result
Subtotal: __________ 13. Add steps 9 through 12 and enter the result.
__________ 14. Enter the result from step 8. This is the available memory.
__________ 15. Enter the result from step 13. This is the total number of words used.
Total: __________ 16. Subtract step 15 from step 14. This number is the amount of memory available to your system.