| April
2004
Welcome to the first newsletter
for 2004.
In the last issue we announced
our 25 th birthday celebrations
would take place this summer.
Well we're still waiting
for summer to appear here this
year as rain, wind and southerlies
rob the best of the good weather.
The Electricity Engineers Association
Annual Conference and Trade Exhibition
is on the 17-19 June 2004.
The Water & Waste Association
46th Annual conference & Expo
is being held 6th -8th October
2004. Both conferences
are being held at the Christchurch
Convention Centre.
Recent sales activity has resulted
in orders for two turnkey SCADA
systems from Nelson Electricity
Limited & the Department of
Corrections, Tongariro - Rangipo.
The Nelson project is for the
replacement of NEL's existing
SCADA systems with a single new
system to provide monitoring,
control and a Load Management
System (to shed controllable load
during peak times). The
new Haven Rd Powerlink RTU will
be fitted with an Injection Controller
module which replaces
the original Semagyr electromechanical
controller comprising a standalone
cabinet
2m high.
The Tongariro - Rangipo system
is a small Powerlink Lite system
with Microlink RTUs to monitor
and control the water and wastewater
pump stations and reservoir level
for the Department of Corrections.
Barry Watson reports recent sales
success in securing an order for
a Powerlink System for an Arkansas
Rural Electrical Coop.
This will bring to 50 the number
of systems we have installed in
the US. Barry's also
involved in two other projects;
on the Eastcoast where Topcats
are being tested in a feederline
automation project and for another
local Coop in Georgia.
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Recently a project was undertaken
to provide "proportional control"
of a valve to maintain the water
level in a tank for treatment
purposes. The inputs to
the control programs were a flow
rate from the water treatment
plant outlet and the water level
in the tank located at a separate
site from the WTP. The
output was the position of a valve
controlling flow into the tank.
The sites were in radio
communication through the Powerlink
SCADA Master.
Traditionally proportional control
uses the classic PID loop theory
algorithm to provide a controlled
variable output based on a measured
variable input. In this
control function the "PID" lable
equates to: Proportional = Gain,
Integral = reset period, Derivative
= rate of change. This
normally requires integration
& differentiation calculas
software functions to be available.
Although Powerlink
programs provide integer arithmetic
functions a good simulation of
the rate of change differential
can be calculated as separate
magnitude and direction values.
The gain and rest period
follow automatically form the
basics of
Powerlink programming.
The result is a small suite of
programs that run at the SCADA
Master and maintain control of
the water level with less than
+-3% output variation and with
minimal overshoot, undershoot
or hunting, etc.
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New products
Mobile Interrogator Unit
Several of our customers have
been using a product called a
Mobile Interrogator Unit (MIU)
for 13-14 years. This was
primarily a system that allowed
field staff to interrogate a pump
station or reservoir from their
trucks. It was developed
and in use before the advent of
cellular phones and used the same
radio network as the SCADA Master
did to communicate with the remote
sites.
.........ffwd
15 years
Todays MIU offering is significantly
more advanced. It's based
on the Handspring Treo 600 handset
with GPRS web access. This
unit also doubles as a phone,
camera, personal organiser and
is a real McGuvyer tool.
It is rated the best of the bunch
by several different IT reviews
and proving popular with customers.
After installation the Treo can
receive and acknowledge SMS alarms,
interrogate sites on a customers
network, receive reservoir levels
and pump statuss and request a
poll to update values.
Customers SCADA PCs will require
browser access.
DNP3 Topcat RTUs
Eric Williams of Control Systems
recently completed a significant
feeder automation upgrade for
our customer WEL Networks Ltd
based in Hamilton.
WEL uses Conitel 2020/2025 protocol
in their network and Topcat RTUs
installed at recloser sites used
C2020 to communicate with the
SCADA Master.
The change meant WEL could move
from continuously polling their
remote recloser sites, to periodic
polling, with the site remotely
initiating a message to the SCADA
Master when an operation occurred.
Upgrading the existing RTUs was
economically viable because the
new Trio digital data radios could
be fitted inside the Topcat RTU,
replacing the existing radio and
saving on significant changes
to the onsite wiring of the RTU.
The Trio SR450 digital data radio
was selected and tested by us
with the Topcat RTU and a kit
developed for the upgrade.
We supplied new Eproms with DNP3
slave firmware for the existing
Topcat RTUs and 20 sites have
now been upgraded over the last
two months.
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Jon Allit & the history
of Telemetry Mimic
TM is an acronym for Telemetry
Mimic - a home grown graphical
user interface (GUI) that we use
to display Powerlink I/O. Abbey
Systems is unusual among
SCADA companies in that we manufacture
both RTUs and write Base Station
User Interface software. Here's
how we got to be that way.
In the early 1990's Abbey Systems
had taken the traditional path
of offering an off the shelf GUI
to provide a modern looking user
interface. At that time the NZ
Electricity Department was being
restructured and corporatised
and was undertaking all sorts
of non-traditional activities
- such as writing software
for GUIs. Jon Allit, one
of the programmers working for
Electricorp Production (as it
was called for a brief time),
had developed a GUI specifically
for their MicroAlert III equipment
and it was used in preference
to our off the shelf offering.
Alas, Electricorp Production was
restructured and all software
development (and developers) were
thrown overboard. Abbey Systems
hired Jon (complete with source
code), and TM became an Abbey
Systems product.
Jon left us in June 1993 to set
up his own commercial computer
graphics company for the advertising
industry. The TM product was taken
over by Daniel Tafili and later
Jacob Lister, and has had many
revisions since then - originally
written in Turbo Pascal, ported
to C++, run on DOS, OS2 and then
Windows NT and
its successors. At the moment
a new release is being prepared
which features impressive new
trending features and a top to
bottom overhaul in structure.
As to Jon Allit - well, after
JJ Graphics he went on the Weta
Workshops where he is now in charge
of all the crowd computer generated
graphics for the Lord of the Rings
series. Look for his name in the
credits - it features prominently.
We're still in contact with Jon
- so who knows, the next release
of TM may feature an army
of Orcs charging out of your overview
screen.
by Lester Abbey
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