Allen-Bradley SLC 500 Series

Publication 1747-RM001G-EN-P - November 2008
C-20 Memory Usage
SLC 5/03, SLC 5/04, or SLC 5/05 Memory Usage Example
1747-L532 processor, 30-slot configuration, (15) 1746-IA16, (10) 1746-OA8, (1)
1747-DCM full configuration, (1) 1746-NI4, (1) 1746-NIO4I
100 data words 100 x 1.00 = 100.00
49 I/O data words 49 x 3.00 = 147.00
30 slot 30 x 3.00 = 90.00
Overhead 236.00
10 is the highest data table file number 10 x 5.00 = 50.00
4 is the highest program file number 4 x 5.00 = 20.00
Subtotal 643.00
Account for additional 4K data space
4096 - 643 = 3453 (result is positive; therefore
12,288 words are available)
50 XIC and XIO 50 x 1.00 = 50.00
15 OTE instructions 15 x 1.00 = 15.00
5 TON instructions 5 x 1.00 = 5.00
3 GRT instructions 3 x 3.00 = 9.00
1 SCL instruction 1 x 4.00 = 4.00
t TOD instruction 1 x 2.00 = 2.00
3 MOV instructions 3 x 2.00 = 6.00
10 CTU instructions 10 x 1.00 = 10.00
10 RES instructions 10 x 1.00 = 10.00
Instruction USage 111.00
30 rungs 30 x 1.00 = 30.00
0 indexed address = 0.00
0 indexed address reference 0.00
Subtotal 141.00
Available memory 12,288.00
Words used - 141.00
Estimated total memory available: 12,147.00