Rockwell Automation 1747-KE,D17476.12 DH-485/RS-232C Interface Module - Manual (Page 123)

Publication 1747-UM005B-EN-P - March 2006
PLC-5 to SLC 500 Communications B-3
Use the PLC-5 Message
Instruction with Word The PLC-5 Message instruction’s octal Destination Address must be
between 010 (base 8) and 177 (base 8). This range corresponds to
word 16 (base 10) through word 254 (base 10) in the SLC processor.
Only even numbered words (16, 18, 20,... 254) in the SLC processor
can be addressed by the PLC-5 Message instruction. The maximum
value for the PLC-5 Message instruction Size in Elements parameter is
112 when the destination is an SLC processor (assuming 1 word
elements).
For example, write 10 words from N7 in a PLC-5 to an SLC 5/02 using
the PLC-5’s Message instruction. To write 10 words:
1. Set up the source address in the Message instruction as N7:0.
2. Set the Size in Elements to 10.
3. Set up the Command Type as PLC-2 Unprotected Write.
4. Set up the Destination Address as 010 (base 8). This corresponds
to the SLC address, N9:16.
Since 10 words will be written, make sure that the N9 file in the SLC
processor is created to at least N9:25.
It is assumed that the Message instruction will be set up for a remote
destination, since there must be a bridge between the PLC-5 processor
and the SLC 5/02 processor, such as a 1784-KA5 linking a DH+ and
the DH-485 network. The 1747-KE module can be used as a bridge
between the DF1 and DH-485 network.