WHERE AUTOMATION CONNECTS
China’s Water...
The seamless integration
of Rockwell Automation
and ProSoft Technology
helps China realize its
goal of enough clean,
fresh water for all its
citizens
by Danetta York
T
he face of China is changing...and so is
its water. Water pollution,
wastewater treatment and water
resource protection have become
a top priority for the Chinese
government. Over the last ten
years, the Chinese government
has enacted a number of antipollution laws and has begun
to educate their citizens on the
importance of water resource
management. China’s Ministry
of Construction proposed last
year that the central government
allocate $2.4 billion USD to
combat water pollution over the
next five years.
China. “I was living by the river
at that time and had to put up
with the smell from the river
over 200 days out of the year.
But things are changing quickly
in China. Now I regret that I
moved away from the river
because today it is clean and fish
and crabs have reappeared.”
Numerous projects have been
implemented throughout China
to help regulate methods for
“A decade ago, you could not see optimizing water distribution.
a single fish in any of China’s
Many drinking water and
main rivers, especially the
wastewater facilities have been
Suzhou River. ” said Alex Xu,
built or are in the planning stages
Manager for Shanghai Yuandong along China’s many waterways.
Science & Technology Ltd.,
The coastal city of Shanghai,
System Integrators for a number with a population of over 16
of water projects throughout
million, has positioned
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itself as a leader in this drive to
revamp China’s water resources.
Shanghai’s Mayor Xu Kuangdi
stated at a conference on
environmental protection that the
“Shanghai government pledged
to transform Shanghai into an
ecological city.”
Application Story #1
Shanghai Wastewater
Treatment Plant
Under the City of Shanghai,
ten huge pumping stations
went on line recently pumping
wastewater to the pre-treatment
plant at Pudong for purification
before being discharged into
the East China Sea. At Pudong,
the waste is purified before
being discharged at a rate of 1.7
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WHERE AUTOMATION CONNECTS
million cubic meters per day
through a 41-kilometer pipeline.
These pump stations are part of
the latest phase of Shanghai’s
Waste Water Treatment Project
(SWWTP) under the auspices of
the Shanghai Municiple Sewage
Company.In 1993, Shanghai
Municipal Sewage Company
conceived the development of
a new wastewater treatment
plant for the city. Plans
were discussed and in 1998
the Shanghai Waste Water
Treatment Project (SWWTP)
was begun. The project is
being implemented in stages
and involves the installation of
approximately 50 huge pumping
stations throughout Shanghai.
Central Control
In January of 1999, General
Electric International began the
construction of the central
monitoring control system,
which
included a centralized master
control station and a total of
34 remote stations located
throughout Shanghai, including
Pudong.
The Master station, using
Australian-developed Managed
Information Technology
Solutions (MITS) MOSAIC
data acquisition and control
technology, communicates to
both Allen-Bradley and General
Electric hardware. Many
water control systems are PCbased and require a high level
of manual intervention, but
the MITS system is highly
automated. While monitoring
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the passage of water, automatic
adjustments can be made to
make the most efficient use of
energy and pumping equipment
and pinpoint problems in
emergencies.
contained Polled Report by
Exception (PRBE). Polled
Report by Exception only allows
the slave to send its data when
the master polls. With a system
this large and complex, True
Report by Exception (TRBE),
DNP Protocol Specified
which allows the slave to send
Immediately following the
its data whenever a change
installation of the central control of status occurs, was needed.
system, Rockwell Automation in The DNP protocol was chosen
Shanghai was contacted to bid
because it contained TRBE as
on the installation of the SCADA well as Date and Time Stamping.
system to control, collect and
monitor data from the 10 pump
stations, some of which are
Integration Solution
as far as 30 miles away from
Since both General Electric
the Master station. In order
and Allen-Bradley equipment
to communicate with the end
were used in the plant, a DNP
devices, the DNP protocol was
interface was needed to allow
specified.
them to communicate with all of
the DNP compatible end devices.
DNP (Distributed Network
Shanghai Electrical Apparatus
Protocol) is an open
Research Institute (SEARI),
communication protocol
the system integrator for the
developed to achieve
project approached Rockwell
interoperability among systems
Automation Shanghai for an
specifically in the electric
integration solution. Rockwell
utility, oil & gas and water/
engineers demonstrated the
wastewater industries. This non- ability of the Allen-Bradley
proprietary protocol, available
PLC-5s to communicate with
worldwide, was designed to
the DNP protocol through the
optimize the transmission of
use of a special communications
data acquisition information
module produced by Rockwell’s
and control commands. It is
Encompass Partner, ProSoft
a highly efficient and reliable
Technology, Inc.
communications protocol
between substation computers,
“Since ProSoft’s 3800-DNP
RTUs, IEDs and master stations. module* has two communication
DNP is also a layered protocol,
ports, SWWTP were able
featuring time stamping and True to install a PLC5 backup
Report by Exception (TRBE).
system as well as a redundant
communication system,” said
Allen-Bradley hardware was
Lenus Hong, Asian Regional
the preferred choice, however,
Sales Manager for ProSoft
Allen-Bradley’s DH+ network
Technology. “DNP Port 1
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WHERE AUTOMATION CONNECTS
is connected to the Master
Station via lease lines, while
Port 2 allows a modem dial up
connection. If communications
should go down on Port 1,
the Master still has dial up
capabilities.”
Dual Redundancy
Redundancy is a key issue
in most wastewater system,
a fact emphasized by Zhou
Ping, Rockwell Automation
Shanghai’s Senior Sales
Engineer.
“When a pumping station has
gone down, it can be very
embarrassing for the client,” he
says. “Potentially, there can be
wastewater in the street. This
means that the reliability of the
entire control system is critical.
It has to run all the time, with
few maintenance or operations
personnel.”
The pump stations are comprised
of 6 to 8 pump sets each—4 to 6
for duty plus 2 stand-by pumps.
The pumps range in size from 30
kW/760 cubic meter per hour to
145kW/2590 cubic meters per
hour.
The control and data
communications system contains
a “hot backup” mode. It is
comprised of two Allen-Bradley
Remote I/O processors so that
in the event of a failure in the
primary controller, the system
will automatically switch to the
backup processor.
Flow and Level Control
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Through a network of flow and
level meters, level and flow data
is relayed back to the central
control station for monitoring
and control. In order to ensure
accurate control, Shanghai
Municipal Sewage Company
specified a quick feedback time
between pump station PLCs and
the central control station.
“Our client specified a system
feedback time of better than
20 milliseconds,” said SEARI
project engineer Zhou Zhiwei.
“This is why we adopted
the PLC-5 series processor
coupled with the ProSoft DNP
modules. It’s the first time the
DNP module has been used in
Mainland China and it’s been a
great success.”
What the Customer Needs
When Rockwell Automation
Shanghai contacted their
Encompass Partner, ProSoft
Technology, Inc., specializing
in inter-network communication
solutions regarding their
3800-DNP module, Rockwell
knew it was exactly what they
needed to allow their PLCs
to communicate via the DNP
protocol. Since the ProSoft
module is designed to fit into
Allen-Bradley PLC racks, it
wasn’t a hard decision to make.
us we set up a demo and
immediately sent it to Shanghai
for testing.”
The Shanghai Wastewater
Treatment Plant is now
operational. Plans are now being
made to expand this system to
cover the areas surrounding
Shanghai.
*Since this project was
implemented, ProSoft’s
3800-DNP module has been
upgraded and renamed to the
MVI 71-DNP module. ProSoft
also has DNP connectivity
solutions for Allen-Bradley’s
SLC, ControlLogix and FLEX
platforms as well as DNP
solutions for Schneider Electric
and Siemens Automation
processors.
“The TRBE features of ProSoft’s
DNP module was the major
factor that convinced SWWTP to
award this million dollar contract
for this phase of the project to
Allen-Bradley,” said Hong.
“When RA-Shanghai contacted
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WHERE AUTOMATION CONNECTS
Application Story #2
Taihe Fresh Water Factory
Flowing from west to east,
across the heart of China is the
Yangzi River. It is the longest
river in China and the third
longest river in the world.
Originating in Tibet, it flows
past the construction site for
the world’s largest dam, the
Yangtzi River Three Gorges
Dam, into the Pacific Ocean at
the city of Shanghai. Raw water
is collected from the Yangzi,
filtered and purified and then
sold to Tap Water Factories such
as the Taihe Water Factory in
Shanghai.
SCADA System
In 1995, Shanghai Taihe Tap
Water Manufacture Ltd. began
construction of the Taihe Water
Factory. Phase I of the project
established a SCADA system for
the factory consisting of an ABB
Modcell Multiloop Controller/
Processor communicating with
Modbus and ABB proprietary
network, ICN.
Clean water could then be
pumped through a series of pipes
to supply the daily tap water
needs for over 43,000 Shanghai
residents.
“When the factory was
established,” said Alex Xu,
Manager for Shanghai Yuandong
Science & Technology Ltd.,
(SYST) the System Integrators.
“It used a SCADA system
only to supervise the working
processes without any control
functionality.”
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In any water system, as complex
as this one, the water flow can
vary dramatically from hour-tohour and day-to-day, depending
on domestic demand cycles and
the more unpredictable aspects
such as rainfall and storms. This
makes it essential that the Master
Control System be equipped,
not only with monitoring
capabilities, but control as well.
Control Ability
“The second phase of the project
planned to add control ability to
the plant,” said Xu. “But they
found it impossible since the
substations were communicating
as slaves, thus couldn’t exchange
data and information between
each other. The main problem
was that data exchanged
between the slaves needed to be
accomplished through the master
node. As long as a personal
computer carried out the master
task, we could not count on its
performance, steadiness and
security. Use of a PLC instead of
the PC was preferred.”
In order to add the control
needed Xu added an AllenBradley PLC5/20E with Ethernet
capabilities. However, since
the original SCADA system
was ABB communicating
with Modbus, an interface was
needed to allow the Modbus end
devices to communicate with
the A-B processor. The solution
Xu found was the Modbus
Communication Module made
by ProSoft Technology, Inc.
Designed to fit in an Allen-
Bradley 1771 PLC rack, the
module contains two active
serial ports, each supporting
RS-232, RS-422 and RS-485,
supports full radio, modem and
multi-drop and is configured
using simple ladder logic. Since
the module communicates over
the backplane, needing only
standard ladder programming,
it provided highly configurable
Modbus Master and Slave
capability to the existing A-B
PLC.
“It was the first time Shanghai
Yuandong Science and
Technology had used our
3100-MCM module,” said Lenus
Hong, Regional Sales Manager
for ProSoft Technology. “ But
it certainly wasn’t the last.
They also installed the module
in the control system for the
compressors in the Shanghai
General Motors Plant. Since the
MCM module fits directly into
Allen-Bradley’s PLC5 racks,
in both instances, it provided
a seamless integration of
technologies.”
“The 3100-MCM module played
an important role in the second
phase of this project,” said Xu.
“Without the ProSoft module,
this phase could not have been
realized.”
When asked what the deciding
factors were in choosing the
ProSoft module for this project,
Chen Zong-Liang, General
Manager for SYST said, “Ease
of operation, higher profits and
ease of implementation...all of
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the above.”
The second phase was completed
in May of 1999.
A Unique Partnership
This unique partnership of
integrated technologies between
Rockwell Automation and
ProSoft Technology has enabled
SCADA systems around the
world to gather data and control
operations in a multitude of
plants just like the Shanghai
Wastewater Plant and the Taihe
Water Factory.
“The 3100-MCM Modbus
module was also used at the
Xin Ning Wastewater Plant in
Suzhou, China,” said Hong.
“According to Rockwell
Automation-Shanghai, the
customer needed to collect
data from Diris Power Meters
which have embedded Modbus
communications. They elected
to use the 3100-MCM module
which allowed them to collect
30 parameters from the power
meters instead of 3 parameters
they would have gotten using
Analog I/O. The bottom line is,
our interface module made more
data available for better control
and monitoring.”
wastewater industry in China.
We are currently presenting
SCADA solutions in conjunction
with Rockwell on two other
large water projects. One
is a wastewater treatment
plant involving ten pumping
stations using our MVI56-101S
module interfacing AllenBradley’s ControlLogix to the
IEC870-5-101 protocol. The
second is a water transportation
project on China’s Yellow
River, using one of our ProLinx
Communication Gateways to
interface Allen-Bradley’s PLC5
processors to DNPNET.”
The seamless integration of
Rockwell Automation and
ProSoft Technology is helping
China realize its goal of enough
clean, fresh water for all of its
citizens.
“China has its problems,” said
Xu. “ But it has faced these
problems and is attempting
to tackle them. Sometimes
the progress may be a little
slow and seem small, but it is
steady and good willing. As
the international community
continues to give real help
and useful advice, things
will go better, smoother and
expeditious.”
“We take great pride in our
ability to help Rockwell
Automation interface with
alternate networks,” said Doug
Sharratt, CEO for ProSoft
Technology, Inc. “We have
been able to provide a number
of solutions for the water/
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