Using Data For Peer-To-Peer Communication - OPTO 22 SNAP-PAC-R1 User Manual

SYSTEM ARCHITECTURE
(For information on using PAC Control, see form #1700, the PAC Control User' s Guide, and form #1701,
the PAC Control Command Reference.)
You use PAC Control on a PC connected to the network, so you can create your control strategy and
download it to the controller. Also included with the SNAP PAC R-series controller is PAC Display, a
full-featured human-machine interface (HMI). PAC Display uses the same tag database as PAC
Control, so points and variables are already defined. Operators, technicians, and engineers running
PAC Display on a Microsoft Windows-based PC on the Ethernet network can see the information
they need, as well as plot trends and respond to alarms.
For applications that require more than one I/O unit, the SNAP PAC R-series controller can control
multiple I/O units through the flowcharts on its control side. These I/O units can be located where
needed on the Ethernet network for distributed control.
The following diagram shows the control side of the controller:
Use to create flowcharts
and download strategy
to SNAP PAC R-series.

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?
22
SNAP PAC R-Series Controller User's Guide
Run PAC Control flowcharts
PAC Control
Shared tag
database
PAC Display
Uses the same
tag database
as PAC Control.
Other Ethernet-based
I/O units
SNAP PAC R-series
I/O Unit
Control Side
I/O Side
Read/write to points
using Memory Map
Memory
Map