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Remote
terminal units (RTUs) are essentially
intelligent data acquisition and control
units. RTUs serve as an efficient front-end
for SCADA applications in a variety of
industries. Whether it is in a coal plant,
a power substation, a mine or along a
railway track or an oil-pipeline, the
rugged and versatile RTU can be easily
installed, maintained and adapted to the
most diverse and demanding physical environments.
Our real-time systems group has developed
the following products for SCADA applications:
Products
The following table shows the possible
applications for the products listed:
|
Application
|
Products
|
| For
SCADA in coal, steel plant, power
sub station, mine, railway track,
pipeline etc. |
CPCI
and PC104 BASED RTUs WITH VSMU
|
Low
end compact applications
Remote unmanned acquisition and control.
|
VSMU
|
| Windows-based
host software |
ASTRA
|
68K
based RTUs
This
RTU has Motorola 68000 microprocessor
as its CPU. It has IO scalable in multiples
of 16, accommodating up to a maximum of
256 IO (any combination and digital and
analog) in a single RTU.
PC-104
based RTU
These
RTUs were developed with different IEC protocols
and proprietary protocols based on customer
needs. The work involved development of
firmware and protocols in RTOS environment
to meet real time needs. This is an open
architecture solution and all peripherals
of PC can directly be used with our RTU.
For instance RTU can have PC monitor for
local display or can be web-enabled.
The
PC-104 based RTUs consist of the following
modules depending on the configuration.
|
|
X86
based CPU card |
|
|
PC104
based digital iInput output (DIO)
module |
|
|
PC104
based serial port module (four RS232/485
Serial ports). |
|
|
Analog
data acquisition modules |
|
|
Signal
conditioning modules.
|
|
|
Modem |
|
|
Power
supply |
|
|
Trivector
meters and numerical relays |
cPCI
based RTU
The
cPCI based RTU is a rugged industrial
data acquisition unit. By virtue of its
open architecture and high-speed back
plane, it is ideal for computational and
signal processing intensive applications.
It can web- enable a product and can provide
versatile interfaces like Profibus, Firewire
etc.
VSMU
The
VSMU module is a stand-alone unit for data
acquisition and can work as slave in master-slave
configuration. The operational role of VSMU
is to acquire analog or digital data from
the field devices. The acquired data is
processed and logged in to memory for future
use after time stamping. In master-slave
configuration the acquired data is reported
to host on query. VSMU communicates with
the host (PC) using MODBUS protocol. VSMU
can monitor 8 digital inputs and 8 analog
inputs and control 8 digital outputs. CPU
is industry standard Atmel micro-controller
and has 8 mega bit flash memory for data
storage
VSMU can be used for a wide range of applications:
|
|
Automobile
applications |
|
|
Instrumentation
applications |
|
|
Process
industry |
|
|
Remote
data acquisition |
Miniaturised
remote terminal unit (MRTU) for railways
power traction:
Miniaturised remote terminal unit (MRTU)
is essentially a data acquisition system
with built-in control features required
for SCADA applications. This SCADA system
is designed to monitor and control geographically
remote AC traction power system facilities
for one or more control centres of the Indian
Railways.
Having
SCADA-under-one-roof, enables RDSO (Railway
Design and Standards Organisation of India)
to study various aspects of SCADA protocols,
impact of communication medium, suitability
of RTUs and the entire SCADA for the given
application. We have provided an effective
solution, which enables RDSO to carry
on the study before implementing SCADA
on the largest railway network in the
world.
SCADA
system is essentially divided into three
parts:
These are the host system, communication
interfaces and miniaturised remote terminal
unit (MRTU). The MRTU is the front-end
device for acquiring the field data and
providing recommended control action.
The
host system at the remote control centre
is responsible for communication with
various MRTU’s, data processing,
control action and man-machine interface.
The master station equipment is installed
indoors at the remote controlled station
where a traction power controller (TPC)
is in-charge of all the control operations.
The
communication interface forms the physical
medium over which the MRTU and host system
communicate for transfer of data and commands.
The protocol that is implemented here
is Standard Protocol for Railway Traction
(SPORT), which is derived from IEC-870-5-1
to suit RDSO requirements.
MRTUs
are intelligent microprocessor based systems
meant for installation in the electrified
section of the Indian Railways at the
controlled posts, one each for:
|
|
Traction
sub station (TSS) RTU (floor mountable). |
|
|
Sectioning
and paralleling post (SP) RTU (pole
mountable). |
|
|
Sub
sectioning and paralleling post (SSP)
RTU (pole mountable). |
Intelligent
electronic device
Intelligent
electronic device (IED) is a 51-core based
card having an RTC, 3 serial ports (one
RS232 and two programmable serial ports),
16 channel 12 bit analog inputs, on board
ambient temperature measurement, door
open switch interface and an expansion
port.
Palmtop-SCADA
Palmtop
SCADA software was developed for monitoring
the device at the site using hand-held
PCs or palmtop PCs powered by Windows
CE. The application was developed using
Visual C++ for Windows CE. Palmtop SCADA
provides GUI optimally designed to fit
the small Palm-top display sizes. It provides
enhanced visual diagnostic support for
installation and commissioning the remote
terminal units.
Web
based SCADA
Leveraging its extensive experience
in SCADA and internet technologies, CMC
has designed and developed an advanced
web- based SCADA system, which is built
around the concept of embedded web-servers
in the remote terminal units and NT based
data servers on the internet.
The
NT based data servers were designed to
acquire data from systems connected over
special purpose communication interfaces
and deliver the same to the different
web-browser based monitoring control stations.
The GUI was designed to be configurable
to suit the needs of different types of
users. The data can be viewed over the
web in different perspectives: as a full
graphics factory view, as a RTU with individual
I/O points displaying information about
the different field devices connected
to it, or as a single I/O card with voltage
levels as seen on the card.
The
data rates are configurable on a individual
user basis, to optimally utilise the internet
bandwidth. Secure access features were
built-in to minimise chances of tampering
with the SCADA system. The active server
pages in conjunction with the Microsoft
IIS were used to provide a complete interface
to the user.
SCADA
and process control applications
Contact
Head
- Embedded systems
CMC Centre
Old Mumbai Highway
Gachibowli,
Hyderabad - 500 032
Tel: 91-40-23000401 / 501
Fax:91-40- 23000509
Email: embedded@cmcltd.com
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