AMR-300-R1
Intelligent Communications Encoder Register
Technical Report
Evolution / Operation / Reliability / Features and Benefits
THIRD GENER A T I O N
The Sensus ICE Register has evolved to provide
greater reliability and accuracy, improved
reading resolution and end-user flexibility. First
introduced for testing by utilities in 2000, it
was preceded by two earlier generations of the
Electronic Communication Register (ECR). The first
generation, engineered and produced by Sensus
predecessor company, Rockwell International,
was introduced for use on water meters in 1984.
In 1989, the 2nd generation incorporated a single
chip micro-processor. A version for all major
brands of residential gas meters was introduced
in 1998.
Since Sensus ICE Registers provide virtually errorfree meter readings, any need for visual meterreading verifications is eliminated.
Although the new generation Sensus ICE
Registers utilize more advanced technology, offer
enhanced features and provide greater reliability
than predecessor versions, they are totally
compatible for use in existing Sensus automated
meter reading systems including TouchRead®,
RadioRead®, PhonRead® and FlexNet®.
The new generation Sensus ICE Registers
utilize more advanced technology, offer
enhanced features and provide greater
reliability.
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AMR-300-R1
TRADITIONA L V I S U A L R E A D I N G /
M ANUAL REC O R D I N G
A reading is obtained by visually reading a register’s
numerical indicators, i. e., odometer-type wheels on
more modern registers (Figure 1); or circular dials on
older water meters and, until very recently, gas and
electric meters (Figure 2). The meter reader either writes
the numbers into a route book, or keys the numbers
into an electronic route book, which has evolved into
storing the information in a solid-state memory. Both
methods are subject to human errors in reading and
recording the data. When the route is completed, the
readings are taken to the utility office where they are
used to calculate customers bills. With paper route
books, the data again must be manually-keyboarded,
usually by a billing clerk, into the billing computer,
lending a second opportunity for human error. The
visual reading / manual recording method is the most
expensive and least efficient method of collecting and
processing meter readings.
Figure 1
Figure 3
readout module to advance the digits on the module
(Figure 3).
Although pulse generator-remotes provided a good
solution for overcoming the problems cited previously,
the remote modules often provided readings different
from those on the meter register, due to electrical
contact and mechanical problems, variations in pulse
integrity and inadequate maintenance practices. The
unreliability of the technology led most state regulatory
agencies to mandate that a reading of the meter
register be conducted each one or two years to insure
that the register and remote module readings were the
same and to synchronize them if they were not.
E A R L Y 1 9 6 0 ’ S – E L E C T R O N I C E NCODED
P U L S E - G E N E R A T I N G T E C H N O L OGY
Figure 2
THE HISTORY A N D E V O L U T I O N O F
M ETER READ I N G M E T H O D S
Understanding the history and evolution of meter
reading methods helps to identify the advantages of the
Sensus ICE Register.
EARLY 1960’ S – P U L S E - G E N E R A T I N G
REGISTERS F O R R E M O T E R E A D I N G
Remote reading equipment, introduced in the 1960’s,
provided for installing a digital counter showing the
meter’s reading at a location away from a meter, usually
on an outside wall of the building in which the meter
was installed. The method was faster, more efficient and
economical as it greatly overcame the need to enter the
building and get to the meter to read it, as well as the
problem of lock-outs resulting from working people not
being at home. It also served to help cut ever-spiraling
labor costs.
Pulse-generating registers electro-mechanically
produce an electrical pulse for each unit of
measurement a register is designed to display, i.e. :
1,000 gallons; 100 cubic feet or 1m3. The electrical pulse
is transmitted over a two-conductor cable to the remote
Some improvement on early pulse-generator
technology came about with the introduction of
registers that replaced the electro-mechanical pulsegenerating mechanisms with switch-closure devices.
In addition to being more reliable, they provided for
obtaining more precise readings and depictions of
usage in much smaller units, i. e. :1 gallon;10 gallon; 1
cubic foot; et cetera.
Although such registers often were referred to as
“electronicallyencoded” by their manufacturers, the
reference meant only that each electric switch closing
generates an electric pulse that is counted and retained
by a battery-powered, electronic memory circuit, either
at the register or at a remote location (Figure 4). When
the memory circuit is interrogated by an electronic
meter reading device, such as a handheld interrogator
/ recorder unit or AMR system telemetry interface
unit, the billing unit pulse count is converted into an
electronically-encoded signal and relayed to the unit.
The method requires an intermediate link, a memory
circuit, to get the reading data from the register to the
data-recording device. Because it is still pulse-based,
the method is not fault-proof and can be subject to
inaccurate readings and, thereby, incorrect billings
Early 1960’s
Mid 1960’s
1970
1984
Visual reading /
manual recording
Pulse-generating registers for remote
reading and electronic encoded pulse-
generating technology
Absolute-encoded
register technology
Sensus TTR
Sensus ECR
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AMR-300-R1
OMNI-204-R2
identification number contained therein, produced the
data as an encoded digital signal, and automatically
transferred the data to the solid-state memory of a
handheld interrogator /recorder or other solid-state
memory.
One of the benefits of encoder registers is that industrystandard interface conventions such as ASCII. This
makes them suitable for use in more advanced AMR
systems. Therefore, encoder registers provide the best
option for compatibility with future information transfer
technologies.
1 9 8 5 – T H E T O U C H R E A D ® S Y S T EM FOR
READING THE ECR-II
Figure 4
to a utility ’s customers. Again, costly periodic visual
readings must be taken and reconciled with those
received by the interrogator / recorder unit. This
technology is still being used by some prominent
manufacturers.
M ID 1960’S – A B S O L U T E - E N C O D E D
REGISTER TE C H N O L O G Y
Absolute-encoded registers were developed in the
mid-1960’s to provide a more reliable and trouble-free
meter-reading system than pulse-based technology
could deliver. The word “absolute” was added to
describe registers that truly did use electronic encoding
technology.
1970 – SENSU S E N C O D E D R E G I S T E R
DEVELOPMEN T
The first encoder register remote reading system,
TeleTape Remote (TTR), was introduced in 1970 by
Sensus predecessor-company, Rockwell International.
The TTR System provided a low-cost, reliable method
of transmitting reading data based on the position of
a register’s wheel positions, to a remote module from
which the data was collected using a portable cassette
tape recorder.
In 1985, Sensus offered the first generation TouchRead®
remote reading system (Figure 6). This system was
the first to use single chip microprocessor technology
and an entirely solid-state data collection device
for reading meters remotely. When powered by the
TouchRead System’s Solid State Interrogator, the
microprocessor scans the registers encoded wheels
and the factory-set register identification number. The
register outputs an encoded digital data signal through
a patented, inductive coupling, half in the TouchPad
and the other half in the tip of the reading gun, into a
portable interrogator where it their electronic output
signal can be formatted to is stored for later retrieval.
The technology provides for obtaining readings
without conventional, troublesome “plug-in” electrical
connectors used in other remote reading systems.
Encoder-type registers can be accessed for reading
through a remotely-mounted interface module referred
to as a TouchPad®. To obtain a reading, the tip of a
reading “gun,” which is wired to a battery-powered,
handheld interrogation unit, is placed on the TouchPad.
With the touch of a button on the gun, power is
transmitted to the register enabling the electronics
in the register to determine the physical positions of
the register’s odometer wheels. The data is passed
back through the TouchPad into the reading gun and
recorded in one of two ways. (Figure 5).
TTR System registers did not provide a data output
protocol compatible with automatic data transmission
via telephony or radio-based methods.
1984 – INTRO D U C T I O N O F T H E S E N S U S
ELECTRONIC C O M M U N I C A T I O N S
REGISTER (E C R )
In 1984, after 14 years of successful applications of
the Sensus Encoded Register, an advanced version
was introduced and designated the Electronic
Communications Register, or ECR.
The advancement was in the addition of a singlechip microprocessor. The microprocessor scanned
the register’s wheel positions, read a factory-set
Figure 5
1985
1989
2000 and Beyond
Sensus ECR TouchRead®
System for reading the ECR II
ECR II with integrated circuit chip and AMR
Advanced Sensus ICE Register
Revolution
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AMR-300-R1
ŸData is displayed on the reading gun’s screen and
visually read by the meter reader, who then inputs
the data via a keyboard on the handheld recorder.
The process requires the manual transfer of the
data, which lends itself to errors caused by visual
misreadings or incorrect key punching.
ŸWhen the tip of the reading gun is placed on
the TouchPad and activated, the reading data is
automatically transferred to and stored in the
interrogator / recorder. With present technology,
the reading gun can transmit the reading data via a
low-power radio transmission instead of via a cable.
(Figures 5 and 6)
Figure 6
In more advanced AMR systems, one or more encoded
registers can be wired to an electronic interface unit
that transmits the readings data via a short-range radio
transmission or by telephony to a data collector.
1 9 8 9 – A U T O M A T I C M E T E R R E A DING
(AMR) APPLICATIONS
1989 – FURTH E R D E V E L O P M E N T O F T H E
ECR WITH AN I N T E G R A T E D C I R C U I T
CHIP – THE E C R - I I
In 1989, the ECR was upgraded again into the ECR-II
version. The primary new component in the ECR-II
was a custom, application-specific, integrated circuit
chip (ASIC), which provided the distinct benefit of
operating at a much lower power level. It incorporated
advanced technological components and state-of-theart manufacturing processes that provided for better
quality control.
Process improvements for the ECR-II included the
incorporation of a patented moisture barrier inside the
polycarbonate register cover. The feature provided for
confidence in using ECR-II registers in outdoor, oftenflooded meter pits.
The ECR-II register was designed with a pathway for
use in Automatic Meter Reading systems such as
the Sensus RadioRead and PhonRead AMR systems
(Figure 7). For AMR applications, the register has three
screw terminals incorporated in its cover, used for
connecting the register to a telemetry module. The
three terminals provide for power in, signal out and a
ground connection. The output signal is in the industry
standard ASCII code, thereby making it compatible with
AMR interface devices presently provided by major
manufacturers, and highly-likely to be compatible
with future technologies. The technological advances
ushered in with the ECR-II afforded customers options
to build robust, comprehensive communications
systems around the register.
Figure 7
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OMNI-204-R2
THE REVOLU T I O N O F M E T E R R E A D I N G
M ETHODS
Introduced for field testing in 2000, the advanced
Sensus ICE Register provides features and benefits that
are not available in any other meter register.
Despite its advanced design, it is totally backwardcompatible with predecessor ECR and ECR-II-based
systems, making it the most logical choice for each and
every AMR and electronic communication application.
It is also fully-compliant with ANSI/AWWA Encoder
Standard C707-82 (R-92). Its wheel position sensing
technology is described in U. S. Patent #5, 796, 250. A
visible indication of its distinctiveness is on the register
face. Instead of the traditional six odometer-type wheels
and a sweep hand, there are eight odometer wheels for
higher resolution and a combination testing pointer and
leak detector (Figure 8).
Figure 9
with that coil. The resonation value is detected and
processed to determine the angular position of each
wheel, and is converted into a numerical value that is
the basis for the reading.
A B S O L U T E E N C O D E R W H E E L P OSITION
SENSING
The Sensus ICE Register continues the proven
and reliable “absolute encoder” technology of its
predecessors. A mechanical, gear-driven odometer
assembly is used for such traditional visual-reading
functions as verification.
ASCII-BASED PROTOCOL FOR
C O M P A T I B I L I T Y W I T H O T H E R B RANDS
OF READERS
Figure 8
LOW-FRICTIO N , N O N - C O N T A C T
WHEEL POSIT I O N S E N S I N G P R O V I D E S
GREATER RE L I A B I L I T Y
The ICE Register utilizes “magnetic-field positionsensing” technology to determine the rotational
position of each odometer wheel and its numerical
value. The electronic reading of data for TouchRead and
AMR applications is derived directly from the rotational
position of the register’s odometer wheels, thereby
insuring a totally-accurate reading value. The design
eliminates mechanical wipers and contacts which are a
source of friction that can result in wear that can cause
malfunctioning. Also eliminated are snap-action spring
mechanisms that add a load to the meter’s measuring
element.
Through “magnetic-field position sensing”, each of the
eight odometer wheels is fitted in the hub area with
a very small coil winding connected in parallel with a
capacitor. (Figure 9).
The odometer assembly is located within a wire cage,
to which an alternating magnetic field is applied
when the register is being interrogated for a reading.
When the alternating magnetic field is applied, the
coil / capacitor on each wheel resonates at a different
frequency, depending on the capacitor value used
The Sensus ICE Register extends the use of the
ASCII-based communication protocol first utilized
by Sensus in 1984. The meter reading data, which
consists of the odometer reading and register ID
number, are transmitted in ASCII code, the standard
data code used by most of the data communications
industry. ASCII encoding methodology requires that
a complete reading of a register wheel contain 10 bits
of information, which includes a “start,” “stop” and
a “parity” bit. The parity bit is used as a self-check
to insure that the interrogation device has correctly
received the data from each wheel.
Although additional data fields have been incorporated,
it can be read by any handheld or AMR reading device
that could read earlier ECR registers. Now widely
considered to be the defacto industry standard, the
Sensus 3-wire AMR interface protocol is made available
free of charge to other AMR equipment manufacturers,
thereby promoting ECR register compatibility with
present and future AMR networks.
I M P R O V E D R E S O L U T I O N F O R T ESTING
AND VISUAL READING
With its eight active odometer wheels, testing the
accuracy of a water meter fitted with an ICE Register
is greatly enhanced. Visual readings are more precise
by a factor of one hundred, thereby enabling a precise
comparison with the volume “standard” of the testing
equipment. Decimal points on the dial face are used
to separate whole units from fractional measurement
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AMR-300-R1
units. Following tradition, the meter’s unit of
measurement, gallons, cubic feet or cubic meters, is
imprinted on the dial face.
PERMANENT , F A C T O R Y - S E T I D
NUMBER
As with its predecessors, ICE Registers incorporate a
unique, neverduplicated identification number that is
factory-set into the register’s non-volatile electronic
memory. The exclusive ID number can be used to
identify a particular meter and link it in a utility ’s billing
computer to the customer served by that meter.
UTILITY PRO G R A M M A B L E
A unique feature, the Sensus ICE Register has four
data fields that can be programmed by a utility for
incorporating and gathering useful information.
One field could be used to identify the register’s unit of
measurement. Another to identify a reading multiplier.
A third, 12-character field could be used to incorporate
a unique ID number. Its 20-character alphanumeric data
field could be used to indicate meter size, a customer
account number or address, or to identify the utility to
protect against inadvertently picking up readings from
an adjoining utility’s meters.
TWO OR THR E E - W I R E R E G I S T E R
INTERROGAT I O N T E C H N O L O G Y
The Sensus ICE Register can be interrogated in either
two-wire mode or three-wire AMR mode, which makes
it totally compatible for incorporation into existing
systems such as two-wire TouchRead or three-wire
RadioRead, PhoneRead or fixed based systems. This
feature makes it easy and economical for a utility that
starts out with a TouchRead System to easily upgrade
to a more-advanced AMR system without having to
replace the registers on its meters.
WATERPROOF PACKAGING
An important requirement for insuring meter reading
integrity and accuracy is to protect a register’s
electronic components from moisture, dirt, sunlight and
mechanical damage. This is crucial for meters installed
under ground in meter boxes and vaults that are
subject to flooding, as the potential exists for moisture
to pass through a register’s molded polycarbonate
cover and damage its electronic components. Sensus
ICE Registers incorporate a patented, impenetrable
barrier film to protect their electronic components just
as effectively as does a hermetically-sealed register
on a standard, visual-read meter. The design has been
proven effective in more than ten years of use in
extremely harsh conditions.
PROTECTION OF WIRING
CONNECTIONS
Another important requirement for maintaining
reading integrity is to insure that wiring connections
are protected from moisture, and especially critical
for providing long-term operational stability in pitset environments. To prevent moisture-infiltration,
connection components on Sensus electronic registers
are encapsulated (“potted”) at the factory with a special
epoxy material under carefullycontrolled conditions.
ASSURANCE TESTING
Throughout the development of the Sensus ICE
Register, an exhaustive series of performance tests
were conducted to insure that specifications for
reliable, long-term performance would be met. In
addition to testing to assure reading validity in many
of situations, registers were exposed to environments
simulating harsh environmental conditions that might
be encountered in actual installations.
Because the ICE Register uses magnetic-field position
sensing to obtain readings, a special emphasis was
placed on testing for possible influences from external
radiated electro-magnetic fields such as electro-static
discharges from a nearby high-power radio transmitter.
Throughout their testing, the registers proved to be
even more-robust than their predecessors, providing
assurance of dependable, troublefree performance.
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AUTHORIZED SENSUS DISTRIBUTOR
P.O. Box 487 | 450 North Gallatin Avenue
Uniontown, PA 15401 USA
T: 1-800-638-3748
F: 1-800-888-2403
www.sensus.com/water
h2oinfo@sensus.com