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Section 3. System Architecture
All remote communications takes place at the HMI
level and has no impact on the performance of the
closed internal communications level between the
EntelliGuard Messengers and the central processing
units. No external communications are permitted
to take place with the CPUs, thereby insuring the
security of the operating system.
The physical connection for remote communication
is at the system interface Ethernet switch between
the CPUs and the HMI. Additional ports on this 8-
port switch allow up to five external connections
using CAT5 cable. An optional 9-port hub is available
to allow external communication via fiber optic
cable. Up to four local HMIs can be connected to
the system interface Ethernet switch, and a LAN
connection can support multiple remote HMIs. A
local HMI can block out other HMIs (local or
remote) from controlling the circuit breakers in the
switchgear. This provides secure control for the
breakers during any maintenance operations.
Connections to remote HMIs on a LAN can be
through a VPN (virtual private network) firewall
device. The VPN only allows pre-defined remote IP
addresses to have access to the system, further
enhancing the security of Entellisys.
Entellisys can also be interfaced with external
monitoring and control systems via remote com-
munications. Entellisys communicates with external
systems via Modbus TCP protocol, providing an open,
common language for interfacing with SCADA,
building automation, and process systems.
Discrete I/O
Entellisys can interface with external monitoring
and control systems in several ways. The most
conventional means is by way of Discrete inputs
and outputs. Up to 128 I/O points can be defined
for use in monitoring and control systems. Discrete
I/O can be provided in non-redundant or redundant
configurations. Discrete I/O is designed to accept
and provide dry contact operations. A more detailed
discussion of Discrete I/O occurs in Section 10.
Expansion Capabilities
Entellisys switchgear is designed to be easily
modified or expanded to handle change in or
increased loading.
Metering functions, system-wide waveform capture
and most protection can be easily changed with
software upgrades to the CPUs, requiring no
additional hardware. Consequently it is possible to
add features to one CPU while the other one is
operating, and then update the second CPU
when the upgraded CPU is returned to operating
mode. This capability is useful for the life of the
equipment, from the design, through manufactur-
ing, to start-up and operation. Entellisys makes it
easy to keep the equipment up to date with ever-
changing needs.
It is very common to specify "fully equipped future
breaker" cubicles when ordering a substation or
line-up. The fully equipped future breaker cubicle
contains line and load side primary disconnects,
drawout rails, and a cutout in the cubicle door.
Current sensors are located in the compartment
and a Messenger is placed above the breaker
compartment. Adding a new feeder can then be
as simple as removing a cover from the cubicle
door and installing the breaker as well as inputting
the circuit breaker protection settings and data
into the CPUs via the HMI.
Standard bus configurations used in Entellisys
have provisions for future bus extension built in.
Should the switchgear have no future breaker
compartments, additional vertical sections can be
mechanically and electrically connected to the
Entellisys line-up without modifications or the use
of transition sections.
Conclusion
These are the building blocks of an Entellisys low-
voltage switchgear lineup. The Entellisys architecture
enables new, powerful protection, monitoring, and
control capability in a flexible system that can be
updated over the lifetime of the equipment. These
capabilities and application improvements are
discussed in more detail in the following sections.
9
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