Number systems – Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual User Manual
Page 58
Addressing Rules and Examples
Chapter 4
4Ć2
An expression can be used in place of any of the above fields in an
address.
Within the above listed fields of an address specification, numbers are
interpreted as decimal (base 10) unless you indicate that they are octal
(base 8). You can specify an octal number by enclosing the number in
parentheses and starting it with a leading zero. For example, 17 is
interpreted as decimal 17, but (017) is interpreted as octal 17, or decimal
15.
An exception to the above rule occurs when addressing a word in the
input or output sections of PLC–3 memory. In these cases, the word
address
regardless of leading zeros. To express an input or output word address as
a decimal value, enclose the word address within parentheses and
eliminate leading zeros.
In addressing individual bits, parentheses have no affect on the address
interpretation The bit address
starts with a leading zero and as a decimal number if it does not start with
a zero.
Figure 4.1 illustrates these addressing conventions.
Figure 4.1
Examples of Addressing Conventions
Address
Specification
Interpretation (expressed in decimal)
I12:15
Input file 12, word 13
I12:15/15
Input file 12, word 13, bit 15
I12:015/015
Input file 12, word 13, bit 13
I12:(15)
Input file 12, word 15
I12:(015)
Input file 12, word 13
N43:15
Integer file 43, word 13
N043:15
Integer file 43, word 13
N(043):15
Integer file 35, word 13
N(43):15
Integer file 43, word 13
10017-I
Number Systems