Rockwell Automation 1747-KE,D17476.12 DH-485/RS-232C Interface Module - Manual (Page 122)

Publication 1747-UM005B-EN-P - March 2006
B-2 PLC-5 to SLC 500 Communications
PLC-5 Message Instruction When using the PLC-5 Message instruction, the Destination Address is
entered in octal. The PLC-5 processor automatically translates the octal
address to a byte address by doubling the decimal equivalent.
Therefore, 010 (base 8) becomes 16 (base 10) and 177 (base 8)
becomes 254 (base 10). The PLC-5 Message instruction does not allow
an octal address less than 010 (base 8) to be entered.
Use the SLC 500 CIF File In application, the CIF can be thought of as a data buffer between all
the other SLC data files and the DH-485 port. The SLC processor must
be programmed, using ladder logic, to transfer data between the CIF
and the other data files as shown here.
SLC 500 CIF File
The CIF can be managed by designating areas to be written to and
areas to be read from. If it is desired to know when data has changed
in the CIF, use ladder logic to program handshaking bits in your CIF
data.
IMPORTANT
File 9 must be created and defined at the time that
the SLC processor is programmed. File 9 must also
be made large enough to include the unprotected
read and write addressing space. Otherwise, all
unprotected reads and unprotected writes will be
rejected by the SLC processor.
Data Files
0 through 8
Unprotected Read
Unprotected Write
10 through 255
SLC Ladder
Program
CIF (File 9)
SLC 500 Processor
DH-485