Introduction to Automatic Meter Reading and Remote Meter ...€¦ · The automatic meter reading...

Automatic/Remote Meter Reading Copy right:YMPL, Udaipur

11/10/2010 1

Introduction to Automatic Meter Reading and Remote Meter ReadingBy:- Mr. Rajesh Nimare


11/10/2010 2

Utility solution of tomorrow

Metering is century old, Computing is several decades old and communication is new to realize the AMI dream


11/10/2010 3

AMI Technology = Comms technology

Changing customer needs, from products to system.


11/10/2010 4

How communication will impact customers?

• HAN: Communication between single meter and multiple In-Home devices.

• License free, interference tolerant wireless operation: Zigbee 2.4GHz

• Mesh architecture from Zigbee to combat interference.

• Other load control devicescan be controlled using different algorithms. HAN

Load

Control

IHD


11/10/2010 5

Agenda: Automatic Meter Reading

• Introduction to Automatic Meter Reading• Classification of Automatic Meter Reading• Basic model of Remote Meter Reading• PSTN based AMR• Wireless based AMR

– Fundamentals of radio transmission and reception– Low power radio / high power radio based RMR– GSM/ GPRS/ CDMA based RMR

• Physical connection


11/10/2010 6

Introduction to Automatic Meter Reading

• Automatic meter reading is the mechanism of collecting the meter readings (data) electronically.

• Not a new concept for Indian Utilities. (recall: when did you first heard MRI?)

• Components of AMR:• Electronic meter• A data collection mechanism• Media and its compatible Interface device


11/10/2010 7

Meter reading is much beyond just “KWH”

Modern electronic meter records three broad category of data.

Data for invoicing

1. Past month bill-point data.

2. Energy registers

3. Time Of Use

4. Average PF

5. Maximum demand

Historic data

1. Previous bill-points energy/ demand.

2. Load Profile for 6-10 parameters.

3. Programming/ configurations

Installation security data

1. Electrical parameters during meter reading.

2. Tamper and fraud recordings with date, time and snap-shots.


11/10/2010 8

Utility management: Importance of Meter data

Meter Data

Invoicing and Billing Energy Audit Tariff formulation

Electricity Regulator

Engineering Actions

Load Research

Planning

Effective utilities have good data management system


11/10/2010 9

Meter readings are collected in two different ways

Manual reading1. Uses data recording

formats on paper.2. Only partial data is read.3. Prone to errors

Electronic using HHU1. Uses Hand Held Device

called as MRI.2. Reads data electronically.3. Data is checked for

transmission errors.4. No errors.

AMRA is an abbreviation of Automatic Meter Reader’s Association, mostly active in the USA (AMRA) , U.K. UKAMRA and Euro-AMRA.


11/10/2010 10

The automatic meter reading

Automatic Meter reading

Local AMR

1. Uses Hand Held Device

2. Need to visit the site.

3. Time consuming.

Remote AMR

1. Uses telecommunication media

2. Meter can be read from a remote location

3. Saves on travel time and cost.

4. Improves productivity


11/10/2010 11

Benefits of Automatic (electronic) Meter Reading

1. Reliable data.2. Speed of collection.3. Electronic format hence easy interface to the next stage.4. Free from human intervention.5. Ability to collect load profiles, history and tamper details.6. Ability to “Up-load” changed configuration to the meter.7. Improves vigilance as the meter reader HAS to visit the

consumer, no coffee-shop reading.


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1. Save on regular "on-cycle" meter reading

2. Obtain more easily (and in some cases, instantly) initial and final meter readings for opening and closing accounts

3. Streamline high bill investigations

4. Flag potential high consumption before customers get a high bill

5. Help pinpoint system losses

6. Help detect theft of service

7. Enable more frequent readings with little incremental cost

8. Enable custom billing dates

9. Support customized rates (e.g., for large customers)

10. Provide detailed consumption information to customers

11. Provide watchdog services, like leakage monitoring

12. Improve cash flow management

13. Improve revenue forecasting, by tying detailed consumption information to production data and expected billings

14. Aid in rate design

15. Enable more sophisticated rates; i.e., that more closely track costs, or encourage conservation.

16. Improve meter management: ensure meters are properly sized; determine optimal time in service or cumulative registration

17. Reduce bill adjustments

Benefits of an AMR system


11/10/2010 13

Remote AMR = Remote Meter Reading

Definition: Collection of data from a meter from a remote location using telecommunications.

Components of RMR

Meter with communication

abilityCommunication

network.

Utility’s RMR

station

Reporting / bill printing

system

Wired

Wireless

RMR is characterized by the technology used for the “first hop”.

Media interface device


11/10/2010 14

Elements of RMR: Meter with communication ability.

•Meters provided with optically isolated transmitter (Tx) and receiver (Rx)

•Special meters having isolated “electrical” connectivity using RS232 or RS485 physical interface.

•Default and adaptable baud rate (Bits per second)

•Data structure

•Data security embedded (encryption of data)

•Quantum of data they provide (Pay-load)

Semi-duplex: Communication system in which the sender and receiver talks alternatively based on their “turn” to speak/ listen. Most of the meter communicate in “semi-duplex” manner same as we humans.


11/10/2010 15

Media Interface device

• An interface device which interconnects the communication media and energy meter.

• Decided by the communication media selected.

• Eg. Modems, GSM interface etc.

MID connected with the meter are called as “OUT STATION” MID.

MID connected at the utility PC is called as “IN STATION” MID.


11/10/2010 16

Elements of RMR: The communication media

Wired1. Telephone2. RS2323. RS485

Wireless1. Low power radio2. High power radio3. GSM

What is important for utilities is the selection between :

1. Public carrier like Airtel, BSNL etc

2. Create your own communication network


11/10/2010 17

RMR: Communication media selection criteria

1. Cost Y = mx + c (Check the upfront and running cost)

2. Reliability of communication

3. Tamper resistant4. Secrecy5. Immune to environmental/

man-made disturbances6. Ease of interface7. Application


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Transmission Protocols

– Simplex• Communication flow in one direction only –

broadcast television or radio.

– Half duplex• Capable of communication in both directions but

not at the same time – ‘walkie-talkies’

– Full duplex• Simultaneous two-way communication – the

telephone


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Communication Terminology

• Circuit-switched / connection oriented• Packet switched / connectionless


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Circuit Switching

• [historic definition] seeking out and establishing a physical copper path end-to-end.

• implies the need to first set up a dedicated, end-to-end path for the connection before the information transfer takes place.

• once the connection is made the only delay is propagation time.

PSTN


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Packet switching• Store-and-forward network where the block

of transfer is a complete packet. A packet is a variable length block of data with a tight upper bound.

Connectionless

1. No set up is needed.

2. Each packet contains information which allows the packet to be individually routed hop-by-hop.


11/10/2010 22

Store-and-Forward Networks

• Intermediate processors (IMPS, nodes, routers, gateways, switches) along the path store the incoming block of data.

• Each block is received in its entirety, inspected for errors, and retransmitted along the path to the destination. This implies one transmission time per hop.


11/10/2010 23

RMR Communication media: telephone network

Telephone network = Public Switch Telephone Network (PSTN)

Data Concentrator

Telephone Switch

Line card

Fiber

Other switche

s

Two telephone wires have their designation as Ring and Tip.

Data concentrator digitizes the voice @8000 samples

Dial tone is a combination of 350 and 440 Hz tone.

Normal telephony is analog based.

Belongs to the circuit switched system


11/10/2010 24

Modem: Media Interface device for PSTN

Digital dataAnalog

telephone line

Modem = modulator demodulator

Modem is needed wherever an analog system is to be connected to a digital

system

Power supplyISDN = Integrated Subscriber Digital

Network, hence does not need modem for PC/ Meter interface.

Modems allow set-up of their Baud-rate, data-frame, ring-counts and other error correction techniques using “AT” commands.

Configuration for in-station and out-station modems are different.


11/10/2010 25

Setup of PSTN based RMR

RMR Station

Utility’s MIS

RMR Software package

Power supply

Power supply

Analog communication Digital communication

Telephone Switch

Energy Meter with communication facility

Digital communication

Meter reading calls are initiated by the utility: “Out bound dialing”.

SPD


11/10/2010 26

Appropriateness of telephone based RMR

• Available infrastructure

• Reasonable reliability• Moderate fixed

charges.• No charges for

receiving calls.

• Prone to tamper by consumer

• Consumer may keep the number engage. (use CUG)

• Threat of damage due to surges and shifting ground potentials.


11/10/2010 27

Precautions while deploying telephone based RMR

• Domestic and commercial grade modems are NOT suitable for RMR (industrial) use.

• Power supply of the modem should have a surge withstand capability of up to 6kV.

• Modem should be immune to supply voltage variations of -40% and +30% (same as meter).

• Deploy surge protection for the telephone lines.• Deploy dedicated lines as far as possible.


11/10/2010 28

RMR Media: radio communicationAd-hoc communication1. Establish a communication

network as and when needed.

2. Does not need any infrastructural support.

3. No running cost other than regulatory

4. Secrecy5. Low/ high power radio.

Infrastructure based1. Needs a communication

infrastructure.2. Needs a service provider

and hence operational cost.

3. Secrecy - Based on service provider agreement.

4. GSM/ CDMA.


11/10/2010 29

Radio communication fundamentals

Transceiver A Transceiver B

The transmitter and receiver frequency should be the same (KHz / MHz)

Intelligence is transmitted by modifying amplitude/ Phase / frequency of the carrier frequency.

Frequency spectrum is a scarce resource. Hence, often the two way communication is done on the same frequency (channel) by alternatively transmitting and receiving.

(semi-duplex). Technically called as Time Division Duplex (TDD)

A to B B to A A to B B to A A to B B to AA to B B to AA to B B to A

Time


11/10/2010 30

Frequency hopping and spread spectrum

Spread Spectrum Techniques

• The packets are transmitted at changing frequency.

• Both transceivers knows the frequency hop pattern.

• Return confirmation of delivery, or else re-transmission of information.

A to B

B to A

A to B

B to A

Time in mS

Frequency channel

A B

Ok

NOK

OK*

OK repeat


11/10/2010 31

Understanding the media: Radio link budget

A Br

Ht Hr

A = 117 + 40 log D miles + 20 log F MHz – 20 log (Ht x Hr)

D

Fresnel Clearance Zone r = 43.3 x √ (d/4f)

Radio transceivers have transmit power and receiver sensitivity in dBm.

mW to dBm: dBm= 10log 10(milliwatt)

dBm to Watts: Watt = 10 ((dB-30)/30)


11/10/2010 32

The Low Power Radio Based RMR

Transceiver (Tx)• Power: +10 dBm• Frequency: 433 MHz

programmable• Antenna: Internal• Spread Spectrum type: FHSS• RF Power output: 10 mW

Transceiver (Rx)• Sensitivity: -105 dBm• Frequency: 433MHz

programmable• Antenna: Internal• Spread Spectrum type:

FHSS

Using directional antenna the above transceiver (+10dBm and -105dBm) can communicate over 500 mtrs. However, considerations

should be allowed for moving objects and other attenuations.


11/10/2010 33

Layout of a LPR based RMR

Meter1

LPR

Meter7

Meter1

LPR

Meter4

Meter1

LPR

Meter5 Meter

1

LPR

Meter6

Meter1

LPR

Meter3

Meter1

LPR

Meter2

Meter1

LPR

Meter1

LPR

Establish communication

Data collection

Negotiating errors

Switching to the next meter


11/10/2010 34

Salient points of LPR based AMR

Theoretical range is over 200 mtrs, real performance may vary based on factors covered in link-budget.

1. Reading inaccessible meters (e.g. pole top meters)2. Daily meter readings in an Industrial area from a central

location.3. Monitoring in case of tamper prone sites.4. Meter reading in hazardous/ un-safe area.5. Virtually no running cost as no infrastructural services is

hired.6. Can be expanded to a walk-by system or in conjunction

with a data-concentrator an automatic RMR system can be setup.


11/10/2010 35

High power radio / City RMR

Meter1

LPR

Meter1

Meter1

LPR

Meter2

Meter1

LPR

Meter3

Meter1

LPR

Meter4

Data Concentrator

LPR Master

HPR

Cluster 1

Utility’s AMR station with HPR.

Cluster 2

Cluster 3

Cluster 4

Cluster 5

Cluster 6

Cluster 7

Moderate RF power due to tall antenna

No infrastructural cost

Suitable for a high revenue area


11/10/2010 36

Various Cellular Technologies• GSM -Global System for Mobile• CDMA -Code Division Multiple Access• GPRS -General Packet Radio Service• EDGE- Enhanced Data for GSM Evolution• W-CDMA- Wideband CDMA• UMTS- Universal Mobile Telecom System


11/10/2010 37

History

• 1946- Mobile concept appeared in the USA• 1970–BELL LABS introduced Cellular Principle• 1979 – AMPS system in US- Analog

– Advanced Mobile Phone service – US 800 MHz Band• 1980 – TACS & NMT systems-Analog

– Total Access Comm. System -UK 900 MHz Band– Nordic Mobile Telephone Service – Scandinavian

450/900 MHz Band • 1992 - GSM – Digital

– Global System for Mobile Communication – Europe 900 /1800 MHz

• 1992 – JDC – Japanese Digital Cellular -Digital• 1994 – DAMPS –Digital

– Digital AMPS - US 800 MHz Band , IS-54 , IS-136• 1994 – CDMA – Digital

– Code Division Multiple Access System – US 900 MHz , IS-95


11/10/2010 38

Communication Media: GSMGSM history• 1982 Groupe Special Mobile (GSM)• 1986 Field testing of different radio techniques.• 1987 TDMA chosen as access media• 1988 GSM transferred to newly formed ETSI

(European Telecommunication Standard Institute)• 1991 commercial launch of GSM• By 1993 GSM coverage exceeded the projections

made for 1995.


11/10/2010 39

Objectives set by the GSM groupe

• Spectral efficiency• International roaming• Low mobile and base station cost• Good subjective voice quality• Compatibility with other systems such as

ISDN• Ability to support new services


11/10/2010 40

GSM: Cellular structure

• Too many subscribers, limited frequency channels.

• Divide the available frequency channels in small regions called as cells.

• Reuse the frequency channels after 3 cell distance.

F1

F2

F4

F6

F5

F3

F1

F7

F8

Each Cell is a BTS

Each cell has a Cell Global Identity Number (CGI)


11/10/2010 41

The GSM Network

• The mobile station (MS)• Base Station Sub-system (BSS)• Network and Switching Sub-system

(NSS)• Operation and support Subsystem

(OSS)


11/10/2010 42

Mobile Network Architecture

PDN

Data Terminal

HLR/VLR

MSCBSC

OMC(Operation & Maintenance

Center)

Operation Terminal

BTS

HandsetA

X.25

A-bisSS7

Network sub-systemPSTN

Radiosub-system

Mobilestation

UM

SIMcard

MSC

VLR

PSTN

BSS

ISDN


11/10/2010 43

Architecture of GSM Network

Ludhiana

Amritsar

Chandigarh


11/10/2010 44

GSM: The mobile stationMobile station consists of two main elements:

1. Mobile equipment or terminal (for data)

2. The subscriber Identity Module (SIM)

SIM is ISO compliant removable smart card which identifies the terminal

SIM contains International Mobile Subscriber Identity (IMSI). This is a unique number which is different from the telephone number.

SIM is responsible for operation of mobile equipment, location management, authentication and ciphering.

All the calls are routed through SIM, not the mobile equipment.

The concept of SIM was silently resisted by mobile equipment manufacturers. The GSM groupe did in favor of consumer by adapting.


11/10/2010 45

Network and Switching Subsystem (NSS)

• NSS is the main component of the mobile GSM network.– Switching, mobility management, interconnection to other

networks, system control.• Components

– Mobile Service Switching Service (MSC)• Controls all connections via a separate network to/ from a mobile

terminal within the domain of MSC, several BSC can belong to a MSC.

– Databases (scalable, high capacity, low delay)• Home Location Register (HLR)

– Central master database containing user data, permanent and semi-permanent data of all subscribers assigned to the HLR.

• Visitor Location Register (VLR)– Local database for a subset of user data, including data about all user

currently in the domain of VLR


11/10/2010 46

Mobile service switching center (MSC)MSC provides switching functions of the network.

HLR : Home Location register which contains subscribers fixed information

VLR: Visitor Location Register: Information on all the subscribers in the service area (including the roaming visitor)

AUC: Authentication Center: Used to verify users identity, authentication and encryption function.

IWU

EIR: Equipment Identity Register: Stores the IMEI. Stolen mobiles are traced by this.

IWU: Inter Working Unit: Provides interface to various networks of data communication.


11/10/2010 47

GSM: Radio Transmission Aspect.• Spectrum allocation

• 890 to 915 MHz for up-link (Mobile station to base station)

• 935 to 960 MHz for downlink (Base station to mobile station)

• Multiple access:• 124 carriers are spaced

200 KHz. • TDMA divides time on

each carrier frequency into burst period (0.577ms).


11/10/2010 48

When a mobile station is switched onCatches the pilot, seeks service information. Informs its IMSI and location to MSC.

Authentication is carried out by SIM and AuC. EIR is also checked if requested.

The subscription details and location is update in the VLR from HLR in the MSC.

In case of “roaming subscriber” the subscription details are requested from “HOME MSC” and based on remote AuC, the services are released. Both Home MSC and local MSC gets synchronized and VLR is updated.

The user gets the “signal bar” and service area Name on his device.


11/10/2010 49

Multiple access techniques: Serving many users with limited resources (channels)

Multiple access Method

MS & BS share knowledge about

FDMA Frequency

TDMA Time

CDMA PN code

P

Frequency

FDMA

Frequency

P

TimeTime

TDMA

P

Frequency

Time

CDMA


11/10/2010 50

GSM Uses combination of TDMA and FDMA: How long are you connected?

T0 T1 T2 T3 T4 T 7T6T5

4.615 ms

T0

.577 m S

T0 T1 T2 T3 T4 T 7T6T5

4.615 ms

T0

.577 m S

A mobile station receives data for “.577 m S” in every 4.615 mS. Hence each frequency channel can cater 8 calls. There are many channels in a “cell”. Hence the number of simultaneous calls that can be handled in a cell are in multiples of 8.

A background noise is transmitted to the Mobile station which is played during blanking period. The blank is never noticed by human ear / brain.


11/10/2010 51

GSM: Roaming, Location Registration & handover

BTS 1

BTS 2

Base Station Controller (one in a city)

MSC

VLRMobile station sends signal strength of 12 surrounding cells periodically.

MSC, based on the relative signal strength and traffic conditions decides on “Handing over the call to neighboring cell.

MSC, current BTS and new BTS along with the MS are involved in successful handover.

Types of handover

1. Handover of channels in the same cell

2. Handover of cells controlled by the same BSC

3. Handover of cells belonging to the same MSC but controlled by different BSC

4. Handover of cells controlled by different MSC’s.


11/10/2010 52

GSM Data communication properties

• Native Circuit Switch operation• Uplink and downlink channels allocated for a user for

entire call.• Busy user uses only one direction of link so 50% of

the resources are wasted.• Connection establishment time:20-25 seconds• Capacity: 9.6 kBPS• Connections: to any modem service in PSTN.• Billing is based on “time” and not the amount of data.• GPRS is deployed for packet switch data.


11/10/2010 53

GSM Based RMR: Media Interface device• GSM being “digital” does not

needs modem.• MID in GSM is called as GSM

terminal.• GSM data needs individual

subscription (SIM).• GSM terminal has elaborate

“AT” command structure to support data.

• GSM Terminal is an emulated modem with the real modem being IWU.

• Liaison with service provider is necessary.

GSM Termina

l

MSC

IWUModem

PSTN

In Station Modem

Digital Communication

Analog Communication

Digital Communication


11/10/2010 54

Typical GSM based RMR installation in India

Electronic Meter with “RS232” communication port.

GSM terminal with integral Wide range power supply, Antenna and “SIM” card holder.

Meter box

Please note that the Antenna Should be outside/ close to the glass window so that radio signal can pass.

& it works!!!! To earn back its cost


11/10/2010 55

Benefits of GSM Based RMR• Instant installation and its mobility.• Secure, can not be vandalized by cutting wires etc.• Callers other than authorized can be barred.• In-built error correction.• CUG: GSM service providers are prepared to offer close

user group for cheap calls and secrecy.• Facility to send “SMS” in case of tamper, power up-down or

any other abnormal condition which can have a pulse output,

• Potential application of GSM based RMR is monitoring “seasonal consumer” who under quote their “demand” for year round benefit.


11/10/2010 56

GPRS – General Packet Radio Service• Based on existing GSM infrastructure

• Better than GSM in terms of data transfer rates

• Provides more reliability of data transfer – more meters read per day.

• GSM is a CSD method where as GPRS is Packet based technology

• More similar to Internet access and its structure

• Payload is charged.

• Communication over TCP/IP is secure.

• Simultaneous readings of large no. of meters. Remember - Connection less

• Flexible and expandable system


11/10/2010 57

GPRS based RMR System


11/10/2010 58

Understanding CDMA based data transferCDMA = Code Division Multiple Access

A B

The base station transmits coded data for all receivers at the same frequency and similarly all receivers send their information with individual code at the same frequency.

Negotiating a call, the Base station and target receiver agrees on a special code.

Information pertaining to the target receiver is encoded using special code called as PN code. (Pseudo Random code)

Data pertaining to base station and that of the target meter is decoded by using the respective PN code.

PIN codes may repeat once during a continuous communication of 32 days!


11/10/2010 59

How do we get connected to the internet?

Telephone exchange

Dial the service provider (1772)

ISP has a stock of IP-Address

1. A.B.C.D

2. 172.28.126.110

3. 172.109.12.120

4. nnn.nnn.nnn.nnn You are provided with one of the available IP address, e.g. 172.109.12.120

All your queries are forwarded to the selected websites with your IP address 172.109.12.120. You get a reply on 172.109.12.120.

In the next attempt to access internet , you may get a different IP address eg. 172.28.126.110.

The random IP address is called as DYNAMIC or TEMPORARY IP address

You can get permanent IP address if your usage is for 24 hrs x 7 x 30. Else, permanent IP will be expensive.


11/10/2010 60

TCP/IP

A B

D CRouter matches the address with its

routing table.

1. Destination Address?

2. Part of the address Network ID?

3. Default hop?

A.B.C.D

Information is broken into small packets.

Each packet is packed in an Envelope with packet number and address.

Packets are delivered irrespective of the packet No/ sequence

Original page is formed at the receiver.


11/10/2010 61

Lets Summaries, internet access

• Internet uses packet switching connection.• Data transfer over internet needs TCP/IP protocol. Your PC

does the job of breaking the page to packets and building the page from packets.

• Each packet has the sender, receiver address, the packet serial number and data integrity information.

• Remember, your PC connects to the web-site, not the web-site get connected to your PC. Why? Recall: Websites has fixed IP whereas your dialup connection has a Dynamic IP.

• Whereas in circuit switch system, the end-to-end circuit is prior established, whatever you send from end-1, reaches end-2 in nearly real time.


11/10/2010 62

Data transfer over CDMAPoint-to-point data communication is NOT allowed.

Only internet surfing is allowed.

CDMA TERMINAL

TRANSPARENTPC with TCP/IP

stack

Serial to TCP/IP Converter

WWW


11/10/2010 63

CDMA based Remote Meter Reading

Serial to TCP/IP

Converter

WWW. meterdata.com

A permanent IP Number.

Program the black box the address of meterdata.com

Temporary IP Address.

Meter does not have a IP address. Hence, the UTILITY can not reach a meter like telephone based RMR

The meter can reach the meter reading station because MS has a permanent IP address.

Besides the CDMA terminal, you also need the serial-TCP/IP converter, a permanent IP for reading station. The meter is programmed to send its reading or SMS the meter to do so.


11/10/2010 64

Benefits of CDMA based meter reading

• Payload is charged.• Communication over TCP/IP is secure.• The serial to IP converter can be used as

“store-and-forward” device to improve the communication speed.

• Simultaneous readings of 10’s of meters. Remember.. Connection less.


11/10/2010 65

Evolution Path

• 2nd GenerationGSM -9.6 Kbps (data rate)

• 2.5 Generation (Future of GSM)HSCSD (High Speed Circuit Switched Data)

Data rate : 76.8 Kbps (9.6 x 8 kbps)GPRS (General Packet Radio service)

Data rate: 14.4 - 115.2 KbpsEDGE (Enhanced Data for GSM Evolution)

Data rate: 547.2 Kbps (max)

• 3rd GenerationWCDMA (Wide band CDMA)

Data rate : 0.348 – 2.0 Mbps


11/10/2010 66

The digital interface

• Communication in electronic meters have the following characteristics:

• Rate of transmission (baud rate)• Half-duplex / full duplex• Type of digital interface.

Digital Interface:

• Optical port.• RS232 Physical port (internal isolated)• RS485 Physical port (Internal isolated)


11/10/2010 67

The RS232 interface

• Industry standard and is easily available on PC’s and MRI.

• Available in special meters for electrical connectivity to modems / PC’s

• A group of meters can be connected reducing the MID count.

• Suitable for sites having cable run less than 50’.


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Polling: Multiplexing using equipment identification.

• Objective: To connect several meters to a single DCU e.g. PC or modem.

Meter 1

Meter 4 Meter 5 Meter 6

Meter 3Meter 2

?


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Keywords: Global disable, specific enable.

Meter 1

Meter 4 Meter 5 Meter 6

Meter 3Meter 2

Line Driver


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Online Systems

• Data on real time basis • Different from On-demand Systems (AMR/

RMR)• Communication media selection depends

on application & objective of the system to be deployed


11/10/2010 71

MSETCL System Architecture


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HZL System Architecture


11/10/2010 73

Thank you for your attention. Any questions?

[email protected]

Introduction to Automatic Meter Reading and Remote Meter ...€¦ · The automatic meter reading...

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Transcript of Introduction to Automatic Meter Reading and Remote Meter ...€¦ · The automatic meter reading...