CHAPTER 3: SYSTEM ARCHITECTURE
SNAP PAC Brains User’s Guide
21
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Events, Timers,
Event Messages,
Email, Data Log-
ging, Data Mirror-
ing, and Memory
Map Copying
You can configure a SNAP PAC brain to recognize one or a combination of the following
as an event:
•
The state of a point on a 4-channel digital module (on or off)
•
A specific high or low value of an analog point, in Engineering Units
•
A number on a digital counter or a high or low number on a quadrature counter
•
An analog point value or a quadrature counter that is outside an allowable range
•
The state of a bit in the Scratch Pad (on or off)
•
A specific string received by a serial module.
The brain can react automatically to an event in any or all of the following ways:
•
Turning points on 4-channel digital modules on or off (same or different brain)
•
Copying data from one memory map location to another (same or different brain)
•
Logging data
•
Turning a bit in the Scratch Pad on or off
•
Sending a stream packet, an email message, or an SMNP trap
•
Sending a string through a serial module to a serial device
You can also use a timer to set up a delay between the event and the reaction.
Security
You can limit access to SNAP PAC brains either by allowing access only from specific
computers or other devices on the network (IP filtering), or by limiting access to specific
protocols, such as SNMP, that are used with the brain (port access).
Scratch Pad Areas
The Scratch Pad is used primarily for peer-to-peer communication with other SNAP PAC
brains and controllers on the network. See the
PAC Control User’s Guide
.
SNMP
The Simple Network Management Protocol (SNMP) is used to communicate with an
SNMP-based enterprise management system, such as Computer Associates’
Unicenter, Hewlett-Packard’s OpenView, or IBM’s Tivoli. These systems can manage
analog, digital, or serial devices through a SNAP PAC brain just as they manage com-
puter equipment on the Ethernet network.
FTP Server
SNAP PAC brains have a substantial area available for file storage, and data can be
easily moved to and from these files using FTP. For more information on the file system,
see the
PAC Manager User’s Guide
.
Feature
Description
