Rockwell Automation 1771-SPI,D17716.5.122 SPI PROTOCOL INTERFACE - Manual (Page 37)

Chapter
4
4-1
Creating Command and Status Blocks to
Match Your Application
This chapter helps you:
map your data table for command and status blocks
enter initial conditions in command blocks for transfer to the SPI module
determine where you expect to find status returned from the SPI module
You must do this for the following blocks:
MCC and SYS
CCB and CCS
CDB and CDS
Map your data table for command and status blocks as follows:
For Command Blocks MCC, CCB, and CDB
Use command-block worksheets to write down all required information
that your ladder logic must transfer to the SPI module. You must enter
it into command blocks in the data table after you map their addresses.
We show an example worksheet followed by a blank worksheet that you
can use to write down required information for your own application.
For this Command Block See Page
MCC 4Ć2
CCB 4Ć4
CDB 4Ć6
For Status Blocks SYS, CCS, and CDS
Use bit/word maps of status blocks to determine where you can expect
to find status returned from the SPI module. After mapping their
addresses in the data table, use the maps to determine source addresses
for move instructions so your ladder logic can use the status.
If necessary, refer the the corresponding command or status block in
chapter 3 for explanations and locations of parameters.
Objective
Task Overview