Maxiflex P3 PAC User Manual
13
-© Omniflex
UMM126XR18.pdf
Scanner in the CPU slot. The Remote I/O Scanner connects to
the main Controller via a Remote I/O Link. The Remote I/O
Scanner automatically scans the I/O on its Maxiflex Base and
communicates with the Controller CPU to include the remote
I/O in the Controller CPU’s I/O list as if it were local to the
CPU.
SCADA
Supervisory Control and Data Acquisition
The term
SCADA
is often used to identify the supervisory
control software that it used to monitor and control a plant or
process
– hence
SCADA software
Secondary Controller
The Secondary Controller is the Controller in a dual redundant
Controller system that remains on standby while the Primary
Controller is in control. The Secondary Controller monitors the
health of the Primary Controller and assumes control
automatically if the Primary Controller fails.
You may write a User application in any of the IEC61131
programming languages using the Omniflex ISaGraf
Workbench and download it to the Secondary Controller. The
user program in the Secondary Controller can, but does not
need to be, the same program as that in the Primary
Controller.
Slot
All Maxiflex Modules plug into “Slots” on a Maxiflex Base.
There are different types of slots:
PSU Slots contain PSU Modules
CPU Slots contain CPU Modules
I/O Slots contain IOM and NIM Modules
Standby Mode
An operating mode of one of the two dual redundant
controllers in a dual redundant control system when it does not
have control but is available to take control should it be
necessary.
Subscription Service
The subscription service is a common method employed in
many Omniflex products to efficiently replicate data between
nodes on a network. A block of data in a DIT is replicated in
another product DIT across the network by simply configuring
a “subscription”. The receiving node is said to “subscribe” to
the transmitting node’s data.
Supervisory System
This is a third
party
system that is used to monitor and control
the plant or process via the Maxiflex system. This system is
often referred to as the
SCADA
system
Sync Block
A
Sync
Block
is a contiguous block of registers within the
Data
Interchange Table (DIT)
of the
controller
that are synchronised
between
Primary
and
Secondary Controllers
in a dual
redundant controller system. Up to three contiguous blocks of
DIT registers can be defined by the user as
Sync Blocks
and
will be synchronised between controllers in a dual redundant
controller system.
Sync Link
This is a dedicated communications link between
the CPU’s in
the Primary and Secondary Controllers. It is used to
synchronise User program registers, I/O registers and program
execution.
