SYSTEM ARCHITECTURE
SNAP PAC R-Series Controller User’s Guide
18
The following diagram shows the control side of the controller:
Using Data for Peer-to-Peer Communication
What if you have multiple SNAP PAC controllers? What if each one is running a different PAC Control strategy,
and they need to share variable data? Or what if you need to share data between a SNAP PAC System and an
Allen-Bradley Logix-based PLC?
Scratch Pad areas within the SNAP PAC R-series controller’s memory map provide a way for other devices on
the Ethernet network to access data in the controller. For descriptions of the Scratch Pad areas—bits, integers,
floats, and strings—see the
PAC Manager User’s Guide
. For help in using PAC Control commands to access
Scratch Pad areas, see “I/O Unit—Scratch Pad Commands” in Chapter 10 of the
PAC Control User’s Guide
. For
information on communicating with an A-B Logix PLC, see the
EtherNet/IP for SNAP PAC Protocol Guide
.
SNAP PAC R-series
I/O Unit
I/O Side
Read/write to points
using Memory Map
Control Side
Run PAC Control flowcharts
PAC Control
Use to create flowcharts
and download strategy to
SNAP PAC R-series
PAC Display
Uses the same tag
database as PAC
Control
Other Ethernet-based I/O units
Shared tag
database
Memory Map
