Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command User Manual
Page 127
7–40
Communication Commands
Publication 1770Ć6.5.16 - October 1996
Example: Reading the 18th and 19th bytes shown in the example on page
These examples compare two methods for reading SLC 500 dataĊfrom an SLC
500 (assumes S:2/8 = 0 so that word addressing is selected) and from a PLCĆ2
processor. When using the SLC 500 method, you do not multiply by two (as in
step 2, below) as you do with the PLCĆ2 method.
Read N9:9 from SLC 500 processor:
1.
Convert decimal element to hex:
9 (decimal)
0009 (hex)
2.
Put low byte first in address field:
Address
09 00h
Size
xxh
3.
Put 02 (hex) in size field (2 bytes = 1 word):
Address
Size
09 00h
02h
Read octal word 011 from PLCĆ2 processor:
1.
Convert octal element to hex:
11 (octal)
0009 (hex)
2.
Multiply by 2:
0009h x 2 = 0012h
3.
Put low byte first in address field:
Address
12 00h
Size
xxh
4.
Put 02 (hex) in size field (2 bytes = 1 word):
Address
12 00h
Size
02h