energy meters iec 870-5-102 protocol implementation in monitoring pv grid connected systems

ENERGY METERS IEC 870-5-102 PROTOCOL IMPLEMENTATION IN MONITORING PV GRID

CONNECTED SYSTEMS

M. Alonso Abella1, F. Chenlo1, V. Salas2 1 Ciemat – Avda. Complutense, 22 – 28040 Madrid, Spain

Phone: +34 91 3466492; Fax: +34 91 3466037; email: [email protected] 2 Universidad Carlos III – Dpto. de Tecnologia Electrónica. Avda. de la Universidad 30 – 28911 Leganés, Madrid, Spain

Phone: +34 916249197; Fax: +34 916249430; email: [email protected]

ABSTRACT: This work presents in a simple and practical way how read from a computer the energy values recorded

by standard energy meters installed in PV grid connected systems in order to be monitored local or remotely. This

communication can be easily implemented as a software program itself or integrated as a part in any other monitoring

software. Remote energy metering for PV grid connected installations is used, exclusively in most of the installations,

by the electrical company for remote energy metering and automatic billing. Energy meters communications from

any manufacturer must fulfill the IEC 870-5-102 standard, mandatory in Spain, and complemented by the Electrical

Grid Company, REE, regulation. For remote energy metering the user must install a GSM modem and supply to the

electrical companies the phone number and counters addresses and passwords in order to perform automatic energy

telereadings using software programs. Local energy metering is easily implementable trough energy meters RS485

network and the communication protocol explained in this work.

Keywords: Energy meters reading, IEC870-5-102.

1 INTRODUCTION

Energy meters readings can be monitored local or

remotely in using the IEC 870-5-102 communications

protocol and can be used in a specific software o included

as part of the monitoring software of the whole plant. In

PV installation, this Remote energy metering is a

requirement [1] for PV grid connected installations of

power ≥15 kW and it is being to be mandatory for all

general users in near future. This capability is used,

exclusively in most of the installations, by the electrical

company for remote energy metering and automatic

billing. Energy meters communications from any

manufacturer must fulfill the IEC 870-5-102 standard [2],

in Spain mandatory and complemented by the Electrical

Grid Company, REE, regulation [3]. Energy meters

should have optical ports [4] RS232 or RS485. For

remote energy metering the user must install a GSM

modem and supply to the electrical companies the phone

number and counters addresses and passwords in order to

perform automatic energy telereadings using software

programs. In any case, different energy meters

manufacturers have commercially available software

programs, from simple to highly advanced, to perform

telereading and energy meter programming different

operational parameters. Even some engineering

companies that provide PV monitoring are including this

kind of services. In any case, the option presented in this

work is aimed to provide the information to any user with

light programming skill to be able to develop its own

energy meters reading software or include it in a global

monitoring system. Some basic but relevant concepts

from these documents are reproduced here in order to

facilitate to the reader the implementation of simple

commands to read the energy values, integrated by time

periods or load curves and tariff information.

2 COMMUNICATIONS PROTOCOL

The communication protocol is not balanced; there is

a primary device (master) that asks information to one or

more secondary stations (slaves). In our case the master

will be a PC computer and the slaves are each one of the

energy meters, identified by one address in a RS485

network. The information exchanges are performed by

request/respond methods, but also send/reply and

send/confirm modes are supported. The commands or

transmission frame formats can be of fixed and variable

length, 255 characters max., Figure 1.

2.1 Start character

It is the start frame character (1 byte). In variable

length frames is the hexadecimal byte 68, indicated as

H68. It used two times, one for starting frame and other

to indicate the starting of the commands. In the fixed

length frames it is the byte H10.

2.2 Length

Two repeated bytes, each one indicates the number of

bytes in the frame starting for the control field (included)

until the checksum (not included).

START (H68) START (H10)

LENGTH CONTROL FIELD C

LENGTH ADDRESS

START (H68) ADDRESS

CONTROL FIELD C END (H16)

ADDRESS (b)

ADDRESS Figure 1: Transmission

frame formats:

(a) variable length.

(b) fixed length.

APPLICATION SERVICE

DATA UNIT (ASDU)

CHECKSUM

END (H16)

(a)

2.3 Control field

The control field byte (8 bits or 1 octet), C, has the

structure indicated in Figure 2, where:

RES: Reserve (Always 0)

Bite reserved for future applications. Allways0.

PRM: Control Address

<0> Message from slave (respond)

<1> Message from master (start)

FCB: Frame Count Bit.

N=number of info. objects

<0> <1> = alternant bit for consecutive

send/confirm o request/respond messages.

The master alternates the bit FCB for each new

transmission addressed to the same slave

energy meter. Therefore the master should

retain this bit to change in each message to a

salve.

FCV: Habilitates the bit FCB.

<0> FCB no habilitated

<1> FCB habilitated

ACD: Access bit. Ignored in this protocol.

DFC: Data flow control bit.

<0> Next message accepted

<1> Next message rejected(data overflow)

The valid function codes in the frames from master to

slave (PRM=1) are:

0 Remote link reposition, FCV=0.

3 User data, FCV=1.

9 Link state request, FCV=0.

11 Class 2 data request, FCV=1.

The valid function codes in the frames from slaves to

master (PRM=0) are:

0 ACK. Positive acknowledgment.

1 NACK. Not accepted command.

8 User data.

9 NACK. Data not available.

11 Link estate or access request.

C RES PRM FCB FCV 23 22 21 20 PRM=1 master to slave ACD DFC Function Code PRM=0 slave to master

Bit 8 7 6 5 4 3 2 1 Figure 2: Control field C structure.

2.4 Address

Is a 2 bytes slave address with values from 0 (H0000)

to 65535 (HFFFF), unique for each energy meter in the

RS485 network.

2.5 Application Service Data Units (ASDU)

The Application Service Data Unit has the

information sent by masters or slaves en variable length

frames. Only one ASDU can be send by frame. Its

structure will be analyzed in next section.

2.6 Checksum and END character

It is a byte with the arithmetic addition of all frame

bytes, starting by the control field (included) until the

checksum byte (not included). The end of the message is

indicated with the Hexadecimal byte H16.

3 APPLICATION SERVICE DATA UNITS (ASDU)

As indicated in references [2,3] in points 7 and 5

respectively, the general structure of the Application

service data unit, ASDU, Figure 3, is:

A data unit identifier.

One or more information objects.

One or none time label.

3.1 Data unit identifier

The data unit identifier always has the same structure

for all ASDU:

The type identifier (1 byte).

The variable structure qualifier (1 byte).

The cause of transmission (1 byte).

A common record address of the ASDU (3

bytes).

Start frame

START (68H) [1byte]

LENGTH [2bytes]

START (68H) [1byte]

CONTROL FIELD C [1byte]

ADDRESS [2bytes]

Application Service

Data Unit (ASDU)

Da unit identifier

Type identifier

SQ=0 N=nº info objects

Cause of transmission

ASDU address

Information Objects

Info Obj. 1 Info Obj. 1 address

Element or combination

Label time type a (5 bytes) or type b (7 bytes)

Info Obj. 2 Info Obj. 2 address

Element or combination

Label time type a (5 bytes) or type b (7 bytes)

…

ASDU Label time (5 bytes)

Stop frame CHECKSUM [1byte]

END (16H) [1byte]

Figure 3: Variable length frames, showing the complete

structure of the Application Service Data Units (ASDU).

3.1.1 Type identifier

The type identifier is a function number to indicate

the type of action or reading, Table I. The nomenclature

used in the IEC870-5-102 is:

Type identifier :=UI8[1..8]<1..255>

Meaning that is an 8 bits unsigned integer that can have

the values from 1 to 255 (H01 to HFF in hexadecimal).

The values <1..127> are defined in the IEC870-5-102,

while the values <128..255> are for special use and are

defined in the REE document, ref. [3].

Table I: Some of the type identifiers, from ref. [3]

Type identifiers

<8> Operational integrated totals, 4 octets (absolute energy meters readings, in kWh o kVArh)

<11> Periodically reset operational integrated totals <122> Read operational integrated totals of a selected

time range and of a selected range of addresses <123> Read periodically reset operational integrated

totals of a selected time range and of a selected range of addresses

<183> Password and session start <187> Closing session

3.1.2 Variable structure qualifier

It has information about the number of information

objects send in the variable length frame.

The bit number 8, referred as SQ, always is 0. The bits 7

to 1 indicates the number of information objects.

Variable structure qualifier :=CP8{N,SQ}

N=number of information objects:=UI7[1..7]<0..127>

SQ:Sequence :=BS1[8]<0..1> (SQ=0 always)

Bit 8 7 6 5 4 3 2 1

SQ=0 26 25 24 23 22 21 20

Figure 4: Variable structure qualifier.

3.1.3 Cause of transmission

The third octet (byte) of the data unit identifier is the

cause of transmission. The bit nº 8 indicates if it is test or

not. The bit nº 7 refers to positive or negative

acknowledgment and bits 6 to 1 have the cause, with

values from 1 to 63. Usually bits P/N and T are 0.

Cause of transmission :=CP8{Cause,P/N,T}

Cause :=UI6[1..6]<0..63>

P/N :=BS1[7]<0..1>

<0> :=Positive confirm

<1> :=Negative confirm

T=test :=BS1[8]<0..1>

<0> :=no test

<1> :=test

Bit 8 7 6 5 4 3 2 1

T P/N 23 22 21 20 Figure 5: Cause of transmission.

Table II: Cause of transmission, refs. [2,3]


<4> Initialized <5> request or requested <6> Activation <7> activation confirmation <8> deactivation. <9> deactivation confirmation <10> activation termination <13> requested data record not available <14> requested ASDU-type not available <15> Record nº in the ASDU is not known <16> Address specification in the ASDU is not known <17> Requested information object not available <18> Requested integration period not available

3.1.4 Record address of the ASDU

The last three bytes of the data unit identifier have

the common record address of the ASDU, composed by:

Measurement point address, 2 bytes,

:=UI16[1..16]<0..65535>

Record address, 1 byte :=UI8[1..8]<0..255>

Table III: Some of the record addresses, refs. [2,3]

Record addresses

<11> Integrated totals integration period 1 (load curve)

<21> Integrated totals integration period 1 (daily values) <136> Tariff information relative to Contract III

An energy meter can manage until three independent

contacts. In PV the usual contract is type III. REE define

the measurement points as the basic addressing unit at

application level, by contraposition to the link address,

i.e. the energy meter. It is mandatory a password by each

one of the measurement points of the energy meter. Other

optional passwords can provide different access to the

energy meter information and functionality (i.e. an only

read password).

3.2 Information objects

Each information object has:

information object address (optional),

information elements and a

Time label (optional).

3.2.1 Object address

Object address format is indicated in Table IV.

Object address, 1 byte :=UI8[1..8]<0..29>

Table IV: Some of the object address, ref. [3]

Address Information object

<1> Integrated totals Active input <2> Integrated totals Active output <3> Integrated totals Reactive first quadrant <4> Integrated totals Reactive second quadrant <5> Integrated totals Reactive third quadrant <6> Integrated totals Reactive fourth quadrant <7> Reserve 1 data <8> Reserve 2 data

3.2.2 Information elements

They can be one or a combination of information

elements that share the address and time label. Formats

will agree the indicated in section 5.2.2 of reference [3].

The cases of integrated totals and tariff information are

presented as examples in next points.

3.2.2.1 Information elements: integrated totals

Integrated total are 32 bits numbers (energy in kWh

or kVArh) with a qualifier byte, Figure 5.

Integrated totals :=CP40{energy,qualifier}

Energy :=CP32[1..32]<-2,147,483,648..2,147,483,647>

Qualifier byte :=UI8[1..8]<0..255>

Bit 8 7 6 5 4 3 2 1

IV CA CY VH MP INT AL U IV=Valid reading (IV=0)

CA=Synchronized counter

CY= Overflow (CY=1)

VH= Hourly verification (VH=1)

MP= Parameters modification (MP=1)

INT= Intrusion (INT=1)

AL= Incomplete period power fault (AL=1)

U= (0=kWh or kVArh; 1=MWh or MVArh).

Figure 6: Qualifier byte.

3.2.2.2 Information elements: tariff information

The tariff information has the relevant values elaborated

by the energy meter in each tariff billing period. It

includes energy values, maximums, excess and reserve

registers associated to each period according to hourly

discrimination, and the total referred to all tariff periods.

These can of readings usually are referred to monthly

values. The qualifier byte of Table V has the format

indicated in Figure 6.

Table V: Tariff information, refs. [2,3]

Tariff Information

:=CP496{VabA,VinA,CinA,VabRi,VinRi,CinRi,VabRc,

VinRc,CinRc,R7,CR7,R8,CR8,VMaxA,FechaA, CMaxA,

VExcA,CExcA,IniDate,EndDate}

VabA = Absolute active

energy := UI32[1..32] <0..4.294.967.295>

VinA = Incremental active

energy := UI32[33..64] <0..4.294.967.295>

CinA = qualifier := UI8[65..72]

VabRi = Absolute reactive

inductive energy := UI32[73..104] <0..4.294.967.295>

VinRi = Incremental

reactive inductive Energy

:= UI32[105..136]

<0..4.294.967.295>

CinRi = qualifier := UI8[137..144]

VabRc = Absolute reactive

capacitive energy

:= UI32[145..176]

<0..4.294.967.295>

VinRc = incremental

reactive capacitive energy

:= UI32[177..208]

<0..4.294.967.295>

CinRc = qualifier := UI8[209..216]

R7 = Reserve 7 := UI32[217..248]

CR7 = qualifier bit := UI8[249..256]

Tariff Information

R8 = Reserve 8 := UI32[257..288]

CR8 = qualifier := UI8[289..296]

VMaxA = Max. Power := UI32[297..328]

<0..4.294.967.295>

FechaA = Max. Power date := UI40[329..368] <timeLabel a>

CMaxA = Qualifier := UI8[369..376]

VexcA = Power excess := UI32[377..408]

<0..4.294.967.295>

CexcA = Qualifier := UI8[409..416]

IniDate = Period start date := UI40[417..456] <timeLabel a>

EndDate = Period end date := UI40[457..496] <timeLabel a>

3.2.3 Time labels

There are two kind of time labels, type a, Table VI, 5

bytes, and type b, 7 bytes, including two additional bytes

for seconds and miliseconds.

Table VI: Time labels type a, refs. [2]

Time label type a (5 bytes)

Time label :=CP40{Minute,TIS,IV,hour,RES1,SU,monthda

y,weekday,month,ETI,PTI,year,RES2}

Minute :=UI6[1..6]<0..59>

TIS=Tariff info :=BS1[7];<0>:=tariffOFF;<1>:=tariffON

IV=Valid :=BS1[8]; <0>:=valid; <1>:=not valid

Hour :=UI5[9..13]<0..23>

RES1=Reserve1 :=BS2[14..15]<0>

SU=Summer time :=BS1[16]; <0>:=standard; <1>:=summer

Month day :=UI5[17..21]<1..31>

Week day :=UI3[22..24]<1..31>

Month :=UI4[25..28]<1..12>

ETI=Energy tariff

info

:=UI2[29..30]<0..2>

PTI=Power tariff

info

:=UI2[31..32]<0..2>

Year :=UI7[33..39]<0..99>

RES2=Reserve2 :=BS1[40]<0>

4 STRUCTURE OF THE SPECIFIC APPLICATION

SERVICE DATA UNITS (ASDU)

In the section 7.3 of the IEC870-5-102 are defined

the ASDU with type identifiers from 1 to 127. In the

section 5.3 of the REE document [3] the ASDU 128 to

149 and 180 to 190. In this section are reproduced the

ASDUs for reading energy values.

4.1 Integrated totals by time interval

The reading of the integrated totals energy values are

performed in two steps. First the master (computer) sends

the ASDU with type identifier 122 (absolute energy

readings) or 123 (incremental energy readings) and the

slave (energy meter) answer with the data contained in

the ASDU with type identifier 8 (absolute) or

11(incremental). The cause of transmission can be any of

the Table II for ASDUs 122 or 123 and 5 (requested) for

ASDUs 8 and 11. The load curve are requested if the

record address is 11, while if it is 21, the daily summary

is requested. Load curve are integrated totals for each

time period programmed in the energy meter, being

multiple of 5 minutes, usually every 15 or 60 minutes. In

ASDUs 8 or 11 the time label refers to the end of the

integration period. The reading of the last integration

period of the day D has date D+1 and time 00:00:00.

4.2 Example of reading Integrated totals by time interval

Let’s assume that energy readings by time intervals

are required for dates from 7th February 2010 at 11:00

hours to the 10th February at 17:00 hours. It is known that

the measuring point address is 1, the contract type is III

and the energy meter address is 7000. ASDU 122 is sent

by the computer to the energy meter and the energy meter

answer with data in ASDU 8. Previously it is necessary to

initiate the conversation and to send the password.

Table VII: ASDU for requesting total integrated energy

readings (from computer to energy meter).

Type identifier = <122> or <123>

SQ=<0> Nº information objects, N=<1>


Measurement point address

Record address=<11[12..13]> or <21[22..23]> (Table III)

First integrated total address, <1..8> (Table IV)

Last integrated total address, <1..8> (Table IV)

Initial time label (5 bytes)

End time label (5 bytes)

Table VIII: ASDU for transmitting total integrated

energy readings (from energy meter to computer).

Type identifier = <8> o <11>

SQ=<0> Nº information objects, Nº integrated totals

Cause of transmission (<5>, requested)

Measurement point address

Record address=<11[12..13]> or <21[22..23]> (Table III)

Object address 1 (Table IV)

Integrated total 1 (5 bytes)

….

Object address n (Table IV)

Integrated total n (5 bytes)

Time label (5 bytes)

4.2.1 Example of command ASDU 122

Table IX: Command example to request total integrated

energy readings, ASDU 122.

Byte Nº Hexadecimal 6815 1568 7358 1B7A 0106

0100 0B01 0800 0B07 020A

0011 0A02 0AC1 16

27 H68 Start frame byte

26 H15 length, H15=21 bytes

25 H15 Length (duplicate)

24 H68 Start frame byte

23 H73 Control field

21..22 H581B Energy meter Address

20 H7A ASDU type identifier,

H7A=122, Table I

19 H01 SQ=0 N=1

18 H06 Cause, (Table II)

17 H01 Measurement point

15..16 H000B Record address(Table III)

H000B=11

14 H01 Address of the first integrated,

H01=1 (Table IV)

13 H08 Address of the last integrated,

H08=8 (Table IV)

8..12 H000B07020A Initial label time

3..7 H00110A020A End label time

2 HC1 Checksum

1 H16 END character

The control field is H73, 0111 0011 in binary, from

Figure 2 the 4 first bits are the function code, 00113

decimal, i.e. User data, FCV=1). Bits 8 to 5, 0111, mean

that: RES=0 (reserve), PRM=1 (master to salve), FCB=1

(frame count bit) y FCV=1 (FCB valid). The ASDU type

identifier is H7A=Dec 122 (Table I). The energy meter

address, decimal Dec 7000=H581B (swap bytes Figure

7). The time labels (5 bytes) are created according Table

VI.

“7/02/10 11:00” becomes “H000B 0702 0A” as

indicated in Table XI, where tariff info was not

considered.

Decimal 7000

Binary (16 bits) 0001 1011 0101 1000

Nº bit 15..12 11..8 7..4 3..0

Hex. 1 B 5 8

High-byte Low-byte

1B 58 Send data 4-dígits Hexadecimal

Figure 7: Energy meter address, from decimal to

Hexadecimal.

Table X: Time label for “7/02/10 11:00”

Time label type a (5 bytes) Dec Bin

minute :=UI6 0 00 0000

TIS=Tariff info :=BS1 0 0

IV=Valid :=BS1 0 0

Hour :=UI5 11 0 1011

RES1=Reserve1 :=BS2 0 00

SU=Summer time :=BS1 0 0

Month day :=UI5 7 0 0111

Week day :=UI3 0 000

Month :=UI4 2 0010

ETI=Energy tariff info :=UI2 0 00

PTI=Power tariff info :=UI2 0 00

Year :=UI7 10 000 1010

RES2=Reserve2 :=BS1 0 0

Table XI: Time label hexadecimal code derivation.

Bin 0000 0000 1101 0000 1110 0000 0100 0000 0101 0000

Bin(swap) 0000 1010 0000 0010 0000 0111 0000 1011 0000 0000

Hex. 0A 02 07 0B 00

Hex. (swap) 00 0B 07 02 0A

Finally the checksum byte is calculated form the

arithmetic addition of all bytes, from the control field

(included) to the checksum (not included), as the hex.

value of the rest of the addition divided by 256.

H73+H58+H1B+H7A+H01+H06+H01+H00+H0B+H01

+H08+H00+H0B+H07+H02+H0A+H00+H11+H0A+H0

2+H0A115+88+27+122+1+6+1+0+11+1+8+0+11+7+

2+10+0+17+10+2+10=449; Rest(449/256)=193=HC1.

4.1.1 Example of command ASDU 8

Answering to ASDU 122 the energy meter sends data

with ASDU 8. An example is presented in Table XII.

Table XII: Command example sent by the energy meter

with total integrated energy data, ASDU 8. Byte Nº Hex. 683E 3E68 0858 1B08 0805 0100

0B01 1801 0000 0002 6E1F 0300

0003 0400 0000 0004 0000 0000

0005 CCBE 0000 0006 980D 0000

0007 0000 0000 8008 0000 0000

8000 81B2 0909 E116

<64> H68 Start frame byte

<63> H3E length, H3E=62 bytes

<62> H3E Length (duplicate)

<61> H68 Start frame byte

<60> H08 Control field

<58..59> H581B Energy meter Address

<57> H08 ASDU type identifier, H08=8,

Table I

<56> H08 SQ=0 N=8

<55> H05 Cause, (Table II)

<54> H01 Measurement point

<52..53> H000B Record address(Table III)

H000B=11

<21> H01 Address of the first integrated,

H01=1 (Table IV)

<46..50> H1801 0000 00 Integrated total 1, Active input, 280

kWh

<45> H02 2nd integrated Address

<40..44> H6E1F 0300 00 Integrated total2, Active output,

204,654 kWh

<39> H03 3rd integrated Address

<34..38> H0400 0000 00 Integrated total3, Reactive quadrant

, 4 kVArh

<33> H04 4th integrated Address

<28..32> H0000 0000 00 Integrated total4, Reactive quadrant

2, 0 kVArh


<22..26> HCCBE 0000

00

Integrated total5, Reactive quadrant

3, 48,844 kVArh


<16..20> H980D 0000 00 Integrated total6, Reactive quadrant

4, 3,480 kVArh


<10..14> H0000 0000 80 Integrated total 7, reserve 1


<8..11> H0000 0000 80 Integrated total 8, reserve 2

<3..7> H00 81B2 0909 Time label, 18 September 01:00

<2> HE1 Checksum

<1> H16 END

Each integrated total energy value has 5 bytes, 4

bytes for the value and the last byte for the qualifier, Fig.

5.For example, the first integrated total, Active output

energy is H6E1F 0300 00. Last byte, H00, is the qualifier

and indicates a valid reading, IV=0, and values in kWh or

kVArh, U=0. The first 4 bytes H6E1F 0300 indicate

204,654 kWh of generated active energy.

Table XIII: Integrated total Hex to Dec conversion. Nº Byte 4 Byte 3 Byte 2 Byte 1

Hex. 00 03 1F 6E

Bin. 0000 0000 0000 0011 0001 1111 0110 1110

Dec. 204 654

4.3 Password and session start

An ASDU 183 (HB7) is used to send the password

and session start. The cause of transmission from master

to salve is 6 (activation) and from slave to master can be

7 (activation confirmation if correct password, positive

confirmation if bit P/N=0 or negative if bit P/N=1, Figure

4) or 14 (ASDU not available).

Table XIV: Password and session start, ASDU 183.

Type identifier = <183>

SQ=<0> Nº information objects, N=<1>


Measurement point

Record address =<0>

Password (4 bytes)

4.3.1 Example: password and session start

In the case of measurement point 1, energy meter

address 7000 and password “12345678” the command

should be H680D 0D68 7358 1BB7 0106 0100 004E

61BC 0010 16, where the password is H4E 61BC 0000 BC 614E12345678.

5 EXAMPLE OF A COMMAND SEQUENCE

An example of a complete commands sequence is

presented in Table XV. As in the previous examples it is

assumed an energy meter with address 7000,

measurement point 1 and password “07”.

Table XV: Full commands sequence, example.

# From computer From energy meter

(1) 1049 581B BC16

(2) 100B 581B 7E16

(3) 1040 581B B316

(4) 1000 581B 7316

(5) 1049 581B BC16

(6) 100B 581B 7E16

(7) 680D 0D68 7358 1BB7

0106 0100 0007 0000

0042 16

(8) 1000 581B 7316

(9) 105B 581B BC16

(10) 680D 0D68 0858 1BB7 0107 0100 0007

0000 0042 16

(11) 6815 1568 7358 1B7A

0106 0100 0B01 0801

0012 0909 0000 1309

09C6 16

(12) 1000 581B 7316

(13) 105B 581B CE16

(14) 6815 1568 0858 1B7A 0107 0100 0B01

0801 0012 0909 0000 1309 095C 16

(15) 107B 581B EE16

(16) 683E 3E68 0858 1B08 0805 0100 0B01

1801 0000 0002 6E1F 0300 0003 0400 0000

0004 0000 0000 0005 CCBE 0000 0006

980D 0000 0007 0000 0000 8008 0000

0000 8000 81B2 0909 E116

(17) 105B 581B EE16

(18) 683E 3E68 0858 1B08 0805 0100 0B01

1801 0000 0002 6E1F 0300 0003 0400 0000

0004 0000 0000 0005 CCBE 0000 0006

980D 0000 0007 0000 0000 8008 0000

0000 8000 82B2 0909 E216

…Sequence is repeated

alternating the Frame

Count Bit...

(19) 6815 1568 0858 1B7A 010A 0100 0B01

0801 0012 0909 0000 1309 095F 16

(20) 6809 0968 5358 1BBB

0006 0100 0088 16

(21) 1000 581B 7316

(22) 107B 581B EE16

(23) 6809 0968 5358 1BBB 0007 0100 0088 16

The commands interpretation of Table XV is the

following:

(1) The computer (master) starts the communication

with a fixed length frame. Control field H49; i.e.

PRM=1 and function code 9, Figure 2.

(2) The energy meter answers with a control field H0B,

i.e. function code 11.

(3) The computer sends a control field H40; i.e. PRM=1

and function code 0: Remote link reposition.

(4) Control field H00, PRM=0 y function code 0: ACK,

positive acknowledgment type confirm.

(7) Password sent, see section 4.2.

(8) Idem to (4)

(9) Control field H5B=Bin 0101 1011, i.e. PRM=1,

FCV=1 and function code 11: Class 2 data request.

(10) The Energy meters returns an ASDU 183 (HB7) of

correct password confirmation (control field H08),

cause H07.

(11) The computer asks to the energy meter for the

integrated total energy values, ASDU 122(H7A),

section 4.1. The initial label time (H01 0012 0909)

is 18/09/09 00:01:00 and the final (H0000 1309 09)

is 19/09/09 00:00:00.

(12) Idem to (4), positive acknowledgment.

(13) Idem to (9), data request.

(14) The Energy meter returns an ASDU 122(H7A) with

control field H08 (user data respond) and cause H07

of confirmation.

(15) Data are again requested, but the frame count bit is

alternated with a control field H7B; i.e. PRM=0,

FCB=1, FCV=1 and function code 11. In each

request it is necessary to alternate the frame count

bit, FCB. In that way the commands

H105B581BCE16 and H107B581B EE16 are sent

alternatively.

(16) The Energy meter answers with the integrated total

energy data for the first requested time period, see

section 4.1.

(19) The energy meter sends an ASDU 122(7A) of

integrated total request, but with a cause bit

H0A(cause 10), showing the end of available data.

(20) Closing session with an ASDU 187 (HBB). The

Energy meter sends (21) a positive

acknowledgement. A data request is sent (22),

considering the previous FCB and finally (23) the

energy meter sends a closing session ASDU 187 and

cause H07 of confirmation.

6 REFERENCES

[1] RD 1110/2007, BOE 224 of 18 September 2007.

Unified Regulation of electric system measurement.

[2] IEC 870-5-102. Telecontrol equipment and systems.

Par 5: Transmission protocols. Section 102: Companion

standard for the transmission of integrated total in electric

power systems. First Ed. 1996-06.

[3] RED ELÉCTRICA ESPAÑOLA, REE. Reglamento

de puntos de medida. Protocolo de comunicaciones entre

registradores y concentradores de medidas o terminales

de medidas o terminales portátiles lectura. Revisión

10.04.02, 10 de Abril de 2002.

[4] UNE EN 62 056-21 section 4.

energy meters iec 870-5-102 protocol implementation in monitoring pv grid connected systems

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