ABOUT THE CONTROLLER’S MEMORY MAP
SNAP PAC S-Series User’s Guide
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ABOUT THE CONTROLLER’S MEMORY MAP
Like SNAP Ethernet-based brains, a SNAP PAC S-series controller uses a memory mapped system for storing
data and making that data available to other devices on the Ethernet network. This data includes
configuration data, status information about the controller itself, and PAC Control strategy variable data that
may be needed by a peer on the network.
Although SNAP PAC S-series controllers are designed to run PAC Control strategies, you can also write your
own software applications to communicate with the controller’s memory map, either instead of or in addition
to using PAC Control. You can use the OptoMMP Communication Toolkit or the IEEE 1394-based protocol for
writing your applications. Both are explained in the
(form 1465) which also includes
complete details of the memory map. Although this guide is written for I/O units, you can use the same
information for a SNAP PAC S-series controller. Just be aware that many sections do not apply, since the
controller’s memory map doesn’t include any I/O point or related information.
The SNAP PAC S-series controller’s memory map includes only the following areas:
Using Data for Peer-to-Peer Communication
Scratch Pad areas within the SNAP PAC S-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
(form 1704). For help in using PAC Control commands to
access Scratch Pad areas, see “I/O Unit—Scratch Pad Commands” in the
(form 1700).
If you are not using PAC Control but writing your own software applications to access the Scratch Pad areas,
see the
OptoMMP Protocol Guide
. This guide is written primarily for I/O units, but much of the same
information on programming applies to SNAP PAC S-series controllers. The Scratch Pad areas of the memory
map are described in the programming guide’s appendix.
If you’re communicating between an Allen-Bradley Logix-based PLC and an S-series PAC, see the
(form 1770).
WHAT’S NEXT?
Your controller is now ready for use.
•
To create PAC Control strategies to run on the controller, see the
(form 1700) and
(form 1701). Both are available for download from the Opto 22
website at
•
To securely access data from I/O points and variables in the PAC’s control strategy, visit
, where you’ll find instructions to set up the PAC’s HTTP/HTTPS server and
complete documentation for the RESTful API.
•
See the
(form 1704) for instructions to work with:
–
Secondary and wireless network interfaces
–
File system and FTP
–
Security settings
–
Port configuration
Status Area Read
Communications Port Configuration
Date and Time Configuration
Status Area Write
Security Configuration
Scratch Pad
PPP Configuration
PPP Status
microSD Card
IP Settings
WLAN Configuration
WLAN Status
