Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 - Manual (Page 76)

Addressing DH and DH+ Data Transfers
Chapter 5
5-2
In addressing individual bits, parentheses have no effect on the address
interpretation. The scanner interprets the bit address
bit as an octal
number if it starts with a leading zero and as a decimal number if it does
not start with a zero.
Some examples are given below:
Address: 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
I12:015 input file 12, word 13
N43:15 integer file 43, word 15
N43:015 integer file 43, word 13
N043:15 integer file 35, word 15
You reference data by its address in memory. In a message command, you
must precede an address with a dollar sign ($). The dollar sign acts as a
delimiter to tell the scanner that it has encountered a data address
(Figure 5.1).
Figure 5.1
Example Assignment Command Showing Addressing Format
$B45:21 = $I12:33
11241
Assignment Command
Source
Address
Destination
Address
Symbols can also be used to represent data in memory. You must precede
a symbolic address with an at sign (@).
There are numerous commands that have been defined for operation on the
DH/DH+ data link. You can program the scanner module to transmit a
subset of these commands as listed in Appendix C, Table C.A. The
command sent by the scanner is dependent on the addressing method you
choose in an assignment command when addressing the data in the remote
station.
Addressing Data
Specifying Addresses