| AdvanTech supplied innovative, automated Boiler
Water Softening systems for several power/steam-generating
stations located in New York City. These Brine
based Regeneration Systems were designed to replace
existing systems employing electromechanical relays,
timers, pushbuttons, switches and lights used
to control and monitor the treatment process.
AdvanTech was responsible for hardware/software
architecture design, hardware/software procurement,
enclosure design/fabrication, all configuration/programming,
documentation/drawings, installation supervision,
start-up, commissioning and training.
The key component of each new system is a cluster
of state-of-the-art PLCs responsible for controlling
the operation of the entire treatment process.
These PLCs are equipped with an appropriate number
of analog and digital input/output (I/O) modules
used for physical interface with field sensors
and field devices. The inputs are responsible
for digitizing all the electrical signals received
from the field sensors (instrumentation, transmitters,
contacts, etc.) and communicating the digitized
data to the PLC CPU for processing. Each CPU is
programmed to examine the field information and
executes a variety of pre-configured control algorithms
(PID, ramp, digital logic, interlocking, etc.).
The result of some of these functions is sent
to the outputs for re-transmission to the field
installed control devices (valves, pumps, motors,
etc.).
All the PLCs are connected to an Ethernet TCP/IP
Local Area Network (LAN). This enabled any PLC
based field or calculated data to be available
to any other device on the LAN. Several PCs, each
equipped with a monitor, keyboard, communication
ports and other required peripherals are also
connected to this LAN. Each PC is configured to
operate completely independently and provides
secure access to all the authorized PLC data.
Each PC executes a SCADA software package responsible
for bi-directional communication with the PLCs
and for providing the operating personnel with
means of monitoring, analyzing and controlling
the treatment process. The supplied SCADA software
performs all the operator interface functions
including supervisory control of the regeneration
process, displaying of all the necessary parameters
on graphic screens, alarm annunciation, data logging,
trending, etc. The user interface software utilizes
menus, prompts and other user-friendly commands
for easy human interaction with the system.
The PLCs together with the I/O modules, power
supplies, relays and other miscellaneous equipment
were factory mounted within Nema 4-type consoles.
This console includes a panel face mounted industrial
PC performing all local operator interface function.
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