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Publication 1763-RM001C-EN-P - October 2009
Appendix
23
Number Systems
This appendix:
•
covers binary and hexadecimal numbers.
•
explains the use of a hex mask to filter data in certain programming
instructions.
Binary Numbers
The processor memory stores 16-bit binary numbers. As indicated in the
following figure, each position in the number has a decimal value,
beginning at the right with 2
0
and ending at the left with 2
15.
Each position can be 0 or 1 in the processor memory. A 0 indicates a
value of 0; a 1 indicates the decimal value of the position. The equivalent
decimal value of the binary number is the sum of the position values.
Positive Decimal Values
The far left position will always be 0 for positive values. As indicated in
the figure, this limits the maximum positive decimal value to 32767. All
positions are 1 except the far left position.
Other examples:
0000 1001 0000 1110
= 2
11
+2
8
+2
3
+2
2
+2
1
= 2048+256+8+4+2 = 2318
0010 0011 0010 1000
= 2
13
+2
9
+2
8
+2
5
+2
3
= 8192+512+256+32+8
= 9000
efesotomasyon.com - Allen Bradley,Rockwell,plc,servo,drive