Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 99)

Transferring Discrete and BlockĆTransfer Data
Chapter 8
8-4
For the supervisory processor, use the adapter’s configured I/O rack
number to receive data or store data for transfer.
Using Rack 3 (Addresses 0:30Ć0:37 and I:30ĆI:37)
Rack 3 is the default discrete-transfer file for PLC-5/12, -5/15, and -5/25
processors. Typically, each output instruction in one processor should have
a corresponding input instruction in the other processor. The rack number
determines the addresses you use.
The ladder logic in the supervisory processor uses the rack number
(0-76 octal) of the adapter-mode processor.
Condition the ladder logic in the adapter processor with I30/10. When
set, this bit indicates a communication failure between the adapter and
supervisory processors.
Creating an Adapter Image FileĊPLCĆ5/12, Ć5/15, and Ć5/25 Processors
If you use 1/2-slot addressing in a 16-slot chassis, you need rack 3
addresses for scanning processor-resident local I/O on the adapter-mode
processor. In this case, you can create an adapter image file for
transferring data. Before you create an adapter image file, make sure that
these conditions are true:
the PLC-5 processor is in adapter mode
the adapter-mode processor is in a 1771-A4B I/O chassis
you are using 1/2-slot addressing
you have not inhibited rack 3 by setting the rack inhibit bit 3 in
processor status word 27
To create the adapter image file, create a 16-word integer file. This file
must be 16 words regardless of whether you use 4-word or 8-word
transfers. This file must be a unique integer file, for use only as an adapter
image file. Words 0-7 are used for output; words 8-15 are used for input.
Bits are numbered in decimal 0-15 for each word.
To tell the processor which file is the adapter image file, enter the file
number in word 25 of the processor status file. You enter this file number
on the processor status screen. For more information about the processor
status screen, see the chapter on using status data in the programming
software documentation.
Important: If you are using an adapter image file (instead of the rack 3
image), then you cannot use block transfers between the supervisor and the
adapter-mode processor.
Programming Discrete
Transfer in Adapter Mode