series pm170 powermeters - satec global · 2 chapter 1 introduction 1.2 eia interface standards...

Series PM170 Powermeters

Communications Manual

LIMITED WARRANTY

The manufacturer offers the customer an 24-month functional warranty on the instrument for faulty workmanship or parts from date of dispatch from the distributor. In all cases, this warranty is good for 36 months from the date of production. This warranty is on a return to factory basis.

The manufacturer does not accept liability for any damage caused by instrument malfunction. The manufacturer accepts no responsibility for the suitability of the instrument to the application for which it was purchased.

Failure to install, set up or operate the instrument according to the instructions herein may void the warranty.

Your instrument should only be opened by a duly authorized representative of the manufacturer. The unit should only be opened in a fully anti-static environment. Failure to do so may damage the electronics and will void the warranty.

NOTE The greatest care has been taken to manufacture and calibrate your instrument. However, these instructions do not purport to cover all possible contingencies that may arise during installation, operation or maintenance, and all details and variations of this equipment do not purport to be covered by these instructions.

For additional information regarding installation, operation or maintenance of this instrument, contact the manufacturer or your local representative or distributor.

BG0045 REV. F

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Table of Contents CHAPTER 1 INTRODUCTION.................................................... 1

1.1 USING THE COMMUNICATIONS PORT.......................................... 1 1.2 EIA INTERFACE STANDARDS ..................................................... 2

1.2.1 EIA RS-232 Standard......................................................... 2 1.2.2 EIA RS-422 and EIA RS-485 Standards ............................ 2

1.3 RESPONSE TIME ......................................................................... 2 1.4 SETUP PARAMETERS .................................................................. 3

1.4.1 Handshaking ...................................................................... 3

CHAPTER 2 PRINT MODE.......................................................... 5 2.1 CONFIGURING THE PRINT MODE PARAMETERS .......................... 5 2.2 CABLE CONNECTIONS ................................................................ 5 2.3 FLOW CONTROL ......................................................................... 5 2.4 PRINTOUT FORMAT .................................................................... 6

CHAPTER 3 ASCII COMMUNICATIONS PROTOCOL......... 8 3.1 ASCII FRAMING ....................................................................... 8 3.2 EXCEPTION RESPONSES.............................................................. 9 3.3 ASCII MESSAGE DESCRIPTION................................................ 10

3.3.1 Read Data Registers ........................................................ 10 3.3.2 Read Basic Setup.............................................................. 12 3.3.3 Write Basic Setup............................................................. 14 3.3.4 Reset/Clear Functions...................................................... 14 3.3.5 Reset Powermeter ............................................................ 15 3.3.6 Read Firmware Version Number ..................................... 15 3.3.7 Read Real Time Clock...................................................... 16 3.3.8 Write Real Time Clock ..................................................... 16

CHAPTER 4 MODBUS COMMUNICATIONS PROTOCOL . 17 4.1 MODBUS FRAMING................................................................ 17

4.1.1 Transmission Mode.......................................................... 17 4.1.2 The RTU Frame Format .................................................. 18 4.1.3 Address Field ................................................................... 18 4.1.4 Function Field.................................................................. 18 4.1.5 Data Field ........................................................................ 19 4.1.6 Error Check Field ............................................................ 19 4.1.7 Data Conversion .............................................................. 21 4.1.8 Data Addressing Modes................................................... 23

4.2 MODBUS MESSAGE FORMATS ............................................... 24 4.2.1 Function 03 - Read Multiple Registers ............................ 24

ii

4.2.2 Function 04 - Read Multiple Registers ............................ 24 4.2.3 Function 20 - Read Multiple Registers ............................ 25 4.2.4 Function 06 - Write Single Register................................. 26 4.2.5 Function 16 - Write Multiple Registers............................ 27 4.2.6 Function 21 - Write Multiple Registers............................ 27 4.2.7 Function 08 - Loopback Communications Test ............... 28

4.3 EXCEPTION RESPONSES............................................................ 29 4.4 POWERMETER REGISTERS ........................................................ 29

4.4.1 Data Registers.................................................................. 29 4.4.2 Basic Setup Registers ....................................................... 32 4.4.3 Real Time Clock Registers ............................................... 35

CHAPTER 5 DNP V3.00 COMMUNICATIONS PROTOCOL36 5.1 DNP PROTOCOL....................................................................... 36

5.1.1 Introduction...................................................................... 36 5.1.2 PM170 Deviation from Standard..................................... 36 5.1.3 DNP Request/Response Overview.................................... 37

5.2 DNP INTERFACE ...................................................................... 37 5.2.1 General ............................................................................ 37 5.2.2 DNP Address.................................................................... 38 5.2.3 Transaction Timing .......................................................... 38 5.2.4 Object Format .................................................................. 39

5.3 SERIES PM170 REGISTERS ....................................................... 39 5.3.1 Data Registers.................................................................. 39 5.3.2 Basic Setup Registers ....................................................... 42 5.3.3 Resetting Energy and Demands ....................................... 43

APPENDIX A DNP APPLICATION MESSAGES .................... 44

APPENDIX B DNP DEVICE PROFILE...................................... 46

INDEX .............................................................................................. 51

WARNING Ensure that all incoming AC power and other power sources are turned OFF before performing any work on the instrument. Failure to do so may result in serious or even fatal injury and/or equipment damage.

This manual is intended for users of communications protocols with the Series PM170 Powermeters. For installation and setup instructions refer to the Series PM170 Powermeters Installation and Operation Manual.

For the safety of personnel and equipment, it is essential to read this manual prior to using the equipment.

Chapter 1 Introduction 1

Chapter 1 Introduction 1.

1.1 Using the Communications Port The Series PM170 communications port supports EIA RS-232, RS-422 and RS-485 standard interfaces allowing connection to a computer, PLC or a printer. The communications port can operate at baud rates up to 9,600 bps. Various communications options may be selected by the user via the front panel.

The communications port can operate in one of two modes:

• computer mode, where a host computer polls the instrument in order to receive data, or to read or program the Powermeter setup parameters

• print mode, where output is provided in printable format.

In the computer mode, the instrument uses a two-way communications protocol. The communications works on a master-slave basis where the Powermeter is the slave, i.e. it responds to host computer requests, but does not transmit information on its own initiative.

The instrument can support two communications protocols: (1) the domain ASCII, and (2) Modicon's Modbus RTU (standard) or DNP V3.00 (option). Each of these protocols can be used by a third-party host-based software to access all data and configuration registers of the Powermeter. Chapters 3, 4 and 5 provide the complete information necessary to develop a third-party communications software capable to communicate with Series PM170 Powermeters. With the ASCII protocol, the Powermeter is capable of connection to a master computer via a modem.

In print mode, the Powermeter can be connected to a serial printer to output a fixed format printed report at user-defined intervals.

2 Chapter 1 Introduction

1.2 EIA Interface Standards 1.2.1 EIA RS-232 Standard

RS-232 is a serial interface standard that may be used for single connections (one computer serial port connected to one instrument), at distances up to 15 meters. It may be possible to extend this range using lower transmission rates, shielded cabling, or repeaters. This standard is generally used when connecting one instrument to a printer. Print mode is available only with EIA RS-232.

1.2.2 EIA RS-422 and EIA RS-485 Standards Both RS-422 and RS-485 are serial differential interface standards, permitting reliable communications for distances up to 1200 meters. Due to the differential mode used, line noise is nullified.

In the RS-422 standard, the interconnection of instruments with a computer is performed via two pairs of lines, one pair for transmission, and one for reception (full duplex). In the RS-485 standard, instruments are connected to a computer via a pair of lines. The same pair is used both for transmission and reception (half duplex).

1.3 Response Time The minimum response time of the Powermeter (to allow the master PC to switch a communications port) is at least 1.75 character time, depending on the baud rate used.

The maximum response time depends on the communications protocol. In ASCII protocol, the Powermeter response time will not exceed 80 ms plus 1.75 character time. For the Modbus RTU protocol, the maximum response time is 80 ms plus 3.50 character time.

Chapter 1 Introduction 3

1.4 Setup Parameters The Powermeter communications port must be configured before connecting it to a master computer or printer. The port and computer/printer configurations must match. Setup instructions are found in the Series PM170 Powermeters Installation and Operation Manual.

1.4.1 Handshaking This optional flow control parameter is used to define the flow control protocol that may be necessary to adjust transmission rate of the Powermeter to the needs of a master computer or a printer. If you do not need to use this parameter, you can leave it on its default setting.

It may be necessary to compensate for the Powermeter's ability to send characters faster than they can be accepted by a modem or printed on a serial printer, when the incoming data buffer is too small. The Powermeter allows hardware and software handshaking.

Hardware handshaking is applicable only in RS-232 communications mode. You can use it to provide DTR/DSR or RTS/CTS flow control protocol by connecting the DTR and RTS/CTS lines to the appropriate pins on the communication connector of the computer or printer.

When hardware handshaking is selected, the Powermeter will not send characters to the communications port until the DSR/CTS signal is asserted high. If the DSR/CTS is dropped during transmission, the Powermeter suspends data transmission until the DSR/CTS is restored.

When hardware handshaking is selected, the DTR signal is permanently asserted high. This outgoing signal may be necessary with certain modems, serial printers or signal converters.

Software handshaking is applicable only in ASCII RS-232 and RS-422 full-duplex communications modes. When a physical connection between the Powermeter and a master

4 Chapter 1 Introduction

computer or a printer is impossible or where hardware flow control is not supported, software handshaking can be used instead. Software handshaking supports the character flow control protocol known as XON/XOFF. The master should send an XOFF character (ASCII DC3) when it wishes the Powermeter to pause in sending data, and an XON character (ASCII DC1) when it wishes the Powermeter to resume transmission.

NOTES In RS-485 half-duplex communications mode, neither hardware nor software handshaking are applicable. If you do not need full-duplex mode, you can use the RS-485 standard in both 4-wire and 2-wire connections (see Communications Cable Connections, Series PM170 Powermeters Installation and Operation Manual).

Chapter 2 Print Mode 5

Chapter 2 Print Mode 2.

2.1 Configuring the Print Mode Parameters When a serial printer is connected to the Powermeter, you should configure communications mode to Prnt/232, and select the appropriate printout period. Baud rate and data format should be configured in the Powermeter as those on the printer. See the Series PM170 Powermeters Installation and Operation Manual for instructions on configuration of the Powermeter communications parameters.

2.2 Cable Connections Cable connections to the printer may depend on the printer connector type. Most serial printers have a DTE 25-pin male connector, but some may have a DCE 25-pin female connector. Refer to the Series PM170 Powermeters Installation and Operation Manual for cable drawings of both connector types.

2.3 Flow Control Most printers provide a few bytes of buffer storage where characters can wait their turn to be printed. If the buffer size is sufficient to accept a full print report, i.e., when a printer has at least 256 bytes of input buffer, flow control is not needed. If the buffer size is less than 256 bytes, you should provide hardware handshaking, otherwise the printer output will become garbled. Use the DSR/CTS signal to provide hardware flow control. In the Powermeter, configure the handshaking mode to HArd .

With a serial-to-parallel converter, you can use a parallel printer as well. When a converter is used, hardware handshaking is required. For setup instructions and cable

6 Chapter 2 Print Mode

drawings, refer to the Series PM170 Powermeters Installation and Operation Manual.

2.4 Printout Format The instrument sends a fixed format printed report at user-defined intervals. After power up or completing the current page, the value heading is printed on the top of the new page. The printing page height is 62 rows. Each row is terminated by ASCII characters CR (ASCII 13) and LF (ASCII 10). On each page, along with a header, 20 readings are printed. The following illustrations show the printout formats for the Series PM170 models: PM170

1 2 3 4 5 6 7 8 9 V1 4

chars

V2 4

chars

V3 4

chars

A1 5

chars

A2 5

chars

A3 5

chars

KW 6

chars

PF 4

chars

FREQ 4

chars 10 11 12

A_MD1 5

chars

A_MD2 5

chars

A_MD3 5

chars

PM170E 1 2 3 4 5 6 7 8 9

V1 4

chars

V2 4

chars

V3 4

chars

A1 5

chars

A2 5

chars

A3 5

chars

KW 6

chars

PF 4

chars

FREQ 4

chars 10 11 12 13 14 15 16

KWH 6

chars

KVAR 6

chars

KVARH 6

chars

A_MD15

chars

A_MD25

chars

A_MD35

chars

MAX_DM6

chars

PM170M 1 2 3 4 5 6 7 8 9 10

V1 4

chars

V2 4

chars

V3 4

chars

A1 5

chars

A2 5

chars

A3 5

chars

KVA 6

chars

KW 6

chars

KVAR 6

chars

PF 4

chars 10 11 12 13 14 15 16 16

KVAH 7

chars

KWH 6

chars

KVARH 6

chars

A_MD15

chars

A_MD25

chars

A_MD35

chars

KVA_MD 6

chars

KW_MD6

chars

I_UB 5

chars

FREQ 4

chars

Chapter 2 Print Mode 7

Table 2-1 lists all measured items presented in the print report with their respective labels and resolution.

Table 2-1 Print Parameters

Parameter label

Description Resolution (no.digits)

V1, V2, V3 Voltage per phase L1/L12, L2/L23, L3/L31

4

A1, A2, A3 Current per phase L1, L2, L3 5

A_MD 1,2,3

Maximum ampere demand per phase L1, L2, L3

5

I_UB Unbalanced current 5

PF Total power factor 4

FREQ Frequency 4

KVA kVA total 6

KW kW total 6

KVAR kvar total 6

MAX_DM Maximum kW demand 6

KW_MD Maximum kW demand 6

KVA_MD Maximum kVA demand 6

KVAH kVAh 6

KWH kWh net 6

KVARH kvarh net 6

8 Chapter 3 ASCII Communications Protocol

Chapter 3 ASCII Communications Protocol 3.

This chapter explains how data is transferred between a master computer station and the Powermeter when the ASCII serial communications protocol is used.

All messages within the ASCII communications protocol are designed to consist only of printable characters.

3.1 ASCII Framing The following specifies the ASCII message frame:

#1 Sync

!

#2 Message

length

#3 Slave

address

#4 Message

type

#5 Message

body

#6 Check sum

#7 Trailer

SYNC - synchronization character: one character '!' (ASCII 33) used for starting synchronization.

Message length - length of the message including only the number of bytes in fields #2, #3, #4 and #5. Contains three characters between '006' and '252'.

Slave address - two characters between '00' and '99'. The Powermeter with address '00' responds to requests with any incoming address. For RS-422/RS-485 communications (multidrop mode), this field must NEVER be zero.

Message type - one character representing the type of a host request. A list of the message types is shown in Table 3-1.

Message body - contains the message parameters in ASCII representation. All parameter fields have a fixed format. The data fields vary in length depending on the data type. If not indicated otherwise, the parameters should be right justified and left-padded with zeros.

Chapter 3 ASCII Communications Protocol 9

The parameters are transferred in a decimal notation ‘as is’, i.e., no conversion is needed. When a value is between 0 and 1, a decimal point must be placed in the data field. When the value range exceeds the field range, it is divided by 1000 and truncated to the right. A decimal point is placed after the thousands to denote that the value has been truncated and must be multiplied by 1000 before processing.

Check sum - arithmetic sum, calculated in 2-byte words over fields #2, #3, #4 and #5 to produce a one-byte check sum in the range of 22h to 7Eh (hexadecimal) as follows: [Σ(each byte - 22H)] mod 5CH + 22H Trailer - two ASCII characters, CR (ASCII 13) and LF (ASCII 10).

NOTE Fields #3 and #4 of the Powermeter response are always the same as those in the host request.

Table 3-1 ASCII Message Types Message type Description

Char ASCII Hex 0 30h Read data registers 1 31h Read basic setup 2 32h Write basic setup 4 34h Reset/clear function 8 38h Program reset 9 39h Read version number

3.2 Exception Responses The instrument will send the following error codes in the message body field in response to incorrect host requests:

XK - Powermeter is in programming mode XP - invalid setup value or setup is not available XM - invalid request type

NOTE When check or framing error is detected, the Powermeter will not act on or respond to the master's request.


3.3 ASCII Message Description 3.3.1 Read Data Registers

This request is used to retrieve a predefined set of the data measured by the Powermeter. All electrical parameters are averaged values over the specified number of the real-time measurements (see the averaging buffer size in Table 3-5).

Host request: Message type - '0'. Message body - none.

Response: Message type - '0'. Message body - see Table 3-2. The message body length: PM170/170E - 163 characters

PM170M - 225 characters

Table 3-2 Response '0' body No. Offset

(bytes) Length (bytes)

Description Unit Range

1 0 4 Voltage L1/L12 V/kV 0 to Vmax 2 4 4 Voltage L2/L21 V/kV 0 to Vmax 3 8 4 Voltage L3/L31 V/kV 0 to Vmax 4 12 5 Current L1 A 0 to Imax 5 17 5 Current L2 A 0 to Imax 6 22 5 Current L3 A 0 to Imax 7 27 6 kW L1 kW/MW -Pmax to Pmax 8 33 6 kW L2 kW/MW -Pmax to Pmax 9 39 6 kW L3 kW/MW -Pmax to Pmax 10 45 4 Power factor L1 -.99 to 1.00 11 49 4 Power factor L2 -.99 to 1.00 12 53 4 Power factor L3 -.99 to 1.00 13 57 6 kW total kW/MW -Pmax to Pmax 14 63 4 Power factor total -.99 to 1.00 15 67 6 kWh net kWh/MWh -999.9 to 9999.9 16 73 5 Unbalanced current A 0 to Imax


No. Offset (bytes)

Length (bytes)

Description Unit Range

17 78 4 Frequency Hz 45.0 to 65.0 18 82 6 kvar L1 kvar/Mvar -Pmax to Pmax 19 88 6 kvar L2 kvar/Mvar -Pmax to Pmax 20 94 6 kvar L3 kvar/Mvar -Pmax to Pmax 21 100 6 kVA L1 kVA/MVA 0 to Pmax 22 106 6 kVA L2 kVA/MVA 0 to Pmax 23 112 6 kVA L3 kVA/MVA 0 to Pmax 24 118 6 kvarh net kvarh/Mvarh

-999.9 to 9999.9

25 124 6 kvar total kvar/Mvar -Pmax to Pmax 26 130 6 kVA total kVA/MVA 0 to Pmax 27 136 6 Maximum kW

demand kW/MW 0 to Pmax

28 142 6 Accumulated kW demand

kW/MW 0 to Pmax

29 148 5 Maximum ampere demand L1

A 0 to Imax


A 0 to Imax


A 0 to Imax

32 163 2 N/A 33 165 6 Maximum kVA

demand kVA/MVA 0 to Pmax

34 171 6 Accumulated kVA demand

kVA/MVA 0 to Pmax

35 177 4 N/A 36 181 4 N/A 37 185 4 N/A 38 189 4 N/A 39 193 4 N/A 40 197 4 N/A 41 201 8 kVAh kVAh 0 to 9999999 42 209 6 kW demand kW/MW 0 to Pmax 43 215 6 kVA demand kVA/MVA 0 to Pmax 44 221 4 Power factor at

maximum kVA demand

-.99 to 1.00


Fields indicated by an N/A mark are padded with ASCII zeros.

When the value width is over the field resolution, the reading is converted to higher units and transmitted with a decimal point. The right most digits of the reading are truncated.

For negative power factor, the minus sign is transmitted before a decimal point as shown in the table.

The parameter limits are as follows: Vmax = 660 [V] if PT Ratio = 1.0 and Vmax = 144*PT Ratio [V] if

PT ratio > 1.0, for the instruments with 660 V input option

Vmax = 144*PT Ratio [V], for the instruments with 120 V input option

Imax = 1.2 * CT primary current [A]

Pmax = (Imax * Vmax * 3)/1000 [kW] if wiring mode is 4L-N

Pmax = (Imax * Vmax * 2)/1000 [kW] if wiring mode is 4L-L, 3-OP, or 3DIR

These parameters are actual for the PM170E/170M only. In the PM170 response, they are passed as zeros.

These parameters are present in the PM170M response only.

NOTES The voltage parameters throughout the protocol can represent line-to-neutral or line-to-line voltages depending on the wiring mode selected in the Powermeter. When a 4L-N wiring mode is selected, they will be line-to-neutral voltages, and when another mode is selected, they will be line-to-line voltages. In 3-wire connection schemes, unbalanced current and the phase readings for power factor, active power, and reactive power will be zeros, because they have no meaning. Only the total three-phase power values can be used.

3.3.2 Read Basic Setup This request is used to retrieve the current basic setup parameters.

Host request: Message type - '1'. Message body - see Table 3-3.


Table 3-3 Request '1' body Field

number Offset (bytes)

Length (bytes)

Description

1 0 3 Parameter identifier (see Table 3-5)

Response: Message type - '1'. Message body - see Table 3-4.

Table 3-4 Response '1' body Field


Length (bytes)

Description

1 0 3 Parameter identifier (see Table 3-5) 2 3 4 Not used (permanently set to 00.0) 3 7 6 Parameter value (see Table 3-5)

Table 3-5 Basic Setup Parameters Parameter Identifier Unit Parameter Range Wiring mode

W40 0 = 3OP, 1 = 4L-N, 2 = 3DIR, 3 = 4L-L

PT ratio U14 1.0 to 6500.0 CT primary current

I17 A 1 to 50000

Power demand period

D11 min 1,2,5,10,15,20,30,60 min 255 = external synchronization

Ampere demand period

C12 sec 0 to 1800 0 = measuring peak currents

Averaging buffer size

S41 8, 32

Reset enable/disable

R42 0 = disable, 1 = enable


3.3.3 Write Basic Setup This request allows you to change any basic setup parameter.

Host request: Message type - '2'. Message body - see Table 3-6.

Table 3-6 Request '2' body Field number

Offset (bytes)

Length (bytes)

Description

1 0 3 Parameter identifier (see Table 3-5) 2 3 4 Not used (set to 00.0) 3 7 6 Parameter value (see Table 3-5)

Response: Message type - '2' Message body - see Table 3-6.

3.3.4 Reset/Clear Functions This request is used to clear accumulated values stored by the Powermeter.

Host request: Message type - '4' Message body - see Table 3-7.

Table 3-7 Request '4' body

Field number

Offset (bytes)

Length (bytes)

Description Range

1 0 1 Reset function see Table 5-8


Table 3-8 Reset/Clear Functions Function Description 1 Clear energy registers 2 Clear maximum demand registers

Response: Message type - '4' Message body - the same as that for the host request.

3.3.5 Reset Powermeter This request causes the Powermeter to perform full reset and restart, such as in the event of power up.


Response: None

3.3.6 Read Firmware Version Number This request is used to retrieve the version of the firmware installed in the Powermeter.


Response: Message type - '9'. Message body - see Table 3-9.

Table 3-9 Response '9' body Field number

Offset (bytes)

Length (bytes)

Description

1 0 3 Firmware version number


3.3.7 Read Real Time Clock This request allows the user to obtain the present RTC indication.

Host request: Message type - 'S'. Message body - none.

Response: Message type - 'S'. Message body - see Table 3-10.

Table 3-10 Response 'S' body Field


Length (bytes)

Description Range

1 0 2 Second 0-59 2 2 2 Minute 0-59 3 4 2 Hour 0-23 4 6 2 Day 1-31 5 8 2 Month 1-12 6 10 2 Year 0-99

3.3.8 Write Real Time Clock This request allows the user to set up the Powermeter RTC.

Host request: Message type - 'T'. Message body - see Table 3-11.

Table 3-11 Request 'T' body Field number

Offset (bytes)

Length (bytes)

Description Range

1 0 2 Second 0-59 2 2 2 Minute 0-59 3 4 2 Hour 0-23 4 6 2 Day 1-31 5 8 2 Month 1-12 6 10 2 Year 0-99

Response: Message type - 'T'. Message body - the same as that for the host request.

Chapter 4 MODBUS Communications Protocol 17

Chapter 4 MODBUS Communications Protocol 4.

This chapter specifies a subset of the Modicon’s Modbus serial communications protocol used to transfer data between a master computer station and the PM170.

4.1 MODBUS Framing 4.1.1 Transmission Mode

The protocol uses the Modbus Remote Terminal Unit (RTU) transmission mode. In RTU mode, data is sent in 8-bit binary characters. The 8 bit even parity or 8 bit no parity data format must be selected when configuring the Powermeter communications. The data format is shown in Table 4-1.

Table 4-1 RTU Data Format

Field Number of bits Start bit 1 Data bits 8 Parity (optional) 1 Stop bit 1

Least significant bit first

18 Chapter 4 MODBUS Communications Protocol

4.1.2 The RTU Frame Format Frame synchronization is maintained in RTU transmission mode by simulating a synchronization message. The receiving device monitors the elapsed time between reception of characters. If three and one-half character times elapse without a new character or completion of the frame, then the device flushes the frame and assumes that the next byte received will be an address. Frame format is defined in Table 4-2.

Table 4-2 RTU Message Frame Format

T1 T2 T3

Address Function Data CRC Check

T1 T2 T3

8 bits 8 bits N * 8 bits 16 bits

The maximum query and response message length is 256 bytes including check characters.

4.1.3 Address Field The address field contains a user assigned address (1-247) of the Powermeter that is to receive the message. Address 0 is used in broadcast mode to transmit to all Powermeters (broadcast mode is available only for functions 06 and 16). In this case all Powermeters receive the message and take action on the request, but do not issue a response.

4.1.4 Function Field The function field contains the function code that tells the Powermeter what action to perform. Function codes used in the protocol are listed in Table 4-3.

Table 4-3 Modbus Function Codes

Code (decimal)

Meaning in Modbus Action in the Powermeter

03 Read holding registers Read multiple contiguous registers


Code (decimal)

Meaning in Modbus Action in the Powermeter

04 Read input registers Read multiple contiguous registers

20 Read general reference Read multiple non-contiguous registers

06 Preset single register Write single register 16 Preset multiple registers Write multiple contiguous

registers 21 Write general reference Write multiple non-

contiguous registers 08 Loopback test Communications test

NOTE Broadcast mode is available only for function codes 06 and 16.

4.1.5 Data Field The data field contains either information the Powermeter needs to perform a specific function or data collected by the Powermeter in response to a query.

NOTE It is important to remember that fields composed of two bytes are sent in the following order: high byte first, low byte second.

4.1.6 Error Check Field The error check field contains the Cyclical Redundancy Check (CRC) word. The start of the message is ignored when calculating the CRC. The CRC-16 error check sequence is implemented as described in the following paragraphs.

The message (data bits only, disregarding start/stop and optional parity bits) is considered one continuous binary number whose most significant bit (MSB) is transmitted first. The message is pre-multiplied by x16 (shifted left 16


bits), then divided by x16 + x15 + x2 + 1 expressed as a binary number (11000000000000101).

The integer quotient digits are ignored and the 16-bit remainder (initialized to all 1’s at the start in order to avoid the case of all zeros being an accepted message) is appended to the message (MSB first) as the two CRC check bytes. The resulting message including CRC, when divided by the same polynomial (x16 + x15 + x2 + 1) at the receiver, will give a zero remainder if no errors have occurred (the receiving unit recalculates the CRC and compares it to the transmitted CRC). All calculations are performed modulo two (no carries).

The device used to serialize the data for transmission will send the conventional LSB or right-most bit of each character first. In generating the CRC, the first bit transmitted is defined as the MSB of the dividend. For convenience, since there are no carries used in performing the calculations, we assume while computing the CRC that the MSB is on the right. To be consistent, the bit order of the generating polynomial must be reversed. The MSB of the polynomial is dropped since it affects only the quotient and not the remainder. This yields 1010 0000 0000 0001 (Hex A001). Note that this reversal of the bit order will have no effect whatever on the interpretation or bit order of characters external to the CRC calculations.

The step by step procedure to form the CRC-16 check bytes is as follows: 1. Load a 16-bit register with all 1's. 2. Exclusive OR the first 8-bit byte with the low order byte of

the 16-bit register, putting the result in the 16-bit register. 3. Shift the 16-bit register one bit to the right. 4. - If the bit shifted out to the right (flag) is one, exclusive

OR the generating polynomial 1010 000 000 0001 with the 16-bit register.

- If the bit shifted out to the right is zero, return to step 3. 5. Repeat steps 3 and 4 until 8 shifts have been performed. 6. Exclusive OR the next 8-bit byte with the 16-bit register.


7. Repeat steps 3 through 6 until all bytes of the message have been exclusive ORed with the 16-bit register and shifted 8 times.

8. When the 16-bit CRC is transmitted in the message, the low order byte will be transmitted first, followed by the high order byte.

For detailed information on CRC calculation, refer to the Modbus Protocol Reference Guide.

4.1.7 Data Conversion In the Powermeter's subset of the Modicon Modbus communications protocol, the following data conversion methods are used to convert the raw data received from the Powermeter into engineering units:

NONE: The data will be presented exactly as retrieved by the communications program from the Powermeter. LIN3 (Linear): This conversion maps the raw data received by the communications program in the range of 0 - 9999 onto the user-defined LO scale/HI scale range. The conversion is carried out according to the formula:

Y = (X / 9999) × (HI - LO) + LO

where:

Y - the value in engineering units X - the raw input data in the range of 0 - 9999 LO and HI - the data low and high scales in engineering units

When data conversion is necessary, the high and low scales and data conversion method are indicated for the corresponding registers.

For example, if you have read the raw voltage value of 5000 from register 256 (see

Table 4-4), and you are using the instrument with the 144V input option and potential transformers with the ratings of 22,000V:110V = 200, then the voltage high scale is


HI = 144×200 = 28,800, and in accordance with the above formula, the voltage reading in engineering units will be as follows: 5000 × (28800 - 0)/9999 + 0 = 14401V When a value is written to the Powermeter, the conversion is carried out in reverse to produce the written value in the range of 0 - 9999:

X = 9999 × (Y - LO) / (HI - LO)

Transmitting fractional numbers Fractional numbers are normally transmitted using the LIN3 data conversion method. For such parameters, the available resolution is indicated by their HI and LO scales.

To represent numbers between 0 and 1 when no conversion is used, a modulus method is applied. Fractional numbers are divided by a modulus and stored in the Powermeter as whole numbers. The modulus depends on the number of decimal digits in the fractional part, i.e., on the value precision. The modulus is given in the form 10-1. To process the value received from the Powermeter in whole-number format, the value must be multiplied by the modulus. To write such a number into the Powermeter, the number must be divided by the modulus.

Transmitting energy values Energy values (registers 287-294 and 301-302) are read and written in two contiguous registers, the first of which contains a low order word and the second contains a high order word. The value is passed via communications in the following format: low order register = value mod 10000 high order register = value / 10000

To get the true energy value, the high order register should be multiplied by 104 and added to the low order register.


4.1.8 Data Addressing Modes Throughout this document, the Powermeter Modbus registers are mapped using the absolute addressing mode. In this mode, the data registers are specified by their absolute addresses in the Powermeter memory map.

Actually, the data registers are organized into tables (files), and in some applications, you may need to access them using the relative addressing mode by specifying the table number and the register offset (relative address) within the table. The table number can be calculated as register address/256. The register offset in the table is calculated as register address mod 256.

From within the Modbus applications, the Powermeter Modbus registers can be accessed by simulating input or holding registers of the Modicon 584, 884, or 984 Programmable Controller. To map the Powermeter register address to the range of the Modicon PLC input or holding registers, add to the register address a value of 30001 or 40001, respectively.


4.2 MODBUS Message Formats 4.2.1 Function 03 - Read Multiple Registers

This command allows the user to obtain contents of up to 125 contiguous registers from a single data table. Request: Powermeter Address

Function

(03)

Starting Address

Word Count

Error Check

1 byte 1 byte 2 bytes 2 bytes 2 bytes

Starting Address Address of the first register to be read

Word Count The number of contiguous words to be read Response: Powermeter Address

Function

(03)

Byte Count

Data Word 1

... Data Word N

Error Check

1 byte 1 byte 1 byte 2 bytes ... 2 bytes 2 bytes

The byte count field contains the quantity of bytes to be returned.

4.2.2 Function 04 - Read Multiple Registers This command allows the user to obtain contents of up to 125 contiguous registers from a single data table. It can be used instead of function 03. Request:

Powermeter Address

Function

(04)

Starting Address

Word Count

Error Check


Starting Address Address of the first register to be read

Word Count The number of contiguous words to be read


Response: Powermeter Address

Function (04)

Byte Count

Data Word 1

... Data Word N

Error Check

1 byte 1 byte 1 byte 2 bytes ... 2 bytes 2 bytes

The byte count field contains the quantity of bytes to be returned.

4.2.3 Function 20 - Read Multiple Registers This command allows the user to obtain contents of non-contiguous data registers from different data tables. Several sub-requests can be included in one message. The maximum number of registers to be read is dependent upon the maximum message length. The maximum query and response message length is 256 bytes, including the error check bytes. This request requires the relative addressing mode to be used (see Section 4.1.8). Request: Powermeter Address

Function ( 20 )

Byte Count

Sub- request 1

... Sub- request N

Error Check

1 byte 1 byte 1 byte 7 bytes ... 7 bytes 2 bytes Sub-request Format: Reference Type (06)

Table Number

Starting Address Word Count

1 byte 2 bytes 2 bytes 2 bytes

Byte Count Total number of binary bytes in the message, excluding the Powermeter address, function code, byte count, and error check fields

Reference type

Fixed field. Must be 06

Table Number The Powermeter Modbus table number Starting Address

Address of the first register to be read in the table (file)

Word Count The number of contiguous words to be read


Response Powermeter Address

Function (20)

Byte Count

Sub- Response

... Sub- Response

Error check

1 byte 1 byte 1 byte ... ... ... 2 bytes

Sub - response Sub-response byte count

Reference Type (06)

Data Word 1

... Data Word N

1 byte 1 byte 2 bytes ... 2 bytes

The sub-response byte count contains the number of binary bytes in each separate sub-response. ‘Data Word 1 ... Data Word N’ are the data from contiguous registers being read.

4.2.4 Function 06 - Write Single Register This command allows the user to write the contents of a data register in any data table where a register can be written. Request:

Powermeter Address

Function (06)

Starting Address

Data Word

Error check


Starting Address Address of the register to be written

Data Word Data to be written to the register Response:

The normal response is the retransmission of the write request.


4.2.5 Function 16 - Write Multiple Registers This request allows the user to write the contents of multiple contiguous registers to a single data table where registers can be written. Request: Powermeter Address

Function (16)

Starting Address

Word Count

Byte Count

1 byte 1 byte 2 bytes 2 bytes 1 byte

Data Word 1 ... ... ... Data Word N

Error Check

2 bytes ... ... ... 2 bytes 2 bytes

Starting Address Address of the first register to be written

Word Count The number of contiguous words to be written

Byte Count The number of bytes to be written


Function (16)

Starting Address

Word Count

Error Check

1 byte 1 byte 2 bytes 1 word 2 bytes

4.2.6 Function 21 - Write Multiple Registers This request allows the user to write the contents of multiple non-contiguous registers into different data tables. Several sub-requests can be included in one message. The maximum number of registers to be written is dependent upon the maximum message length. The maximum query and response message length is 256 bytes including the error check bytes. This request requires the relative addressing mode to be used (see Section 4.1.8). Request: Powermeter Address

Function ( 21 )

Byte Count

Sub- request 1

... Sub- request N

Error Check

1 byte 1 byte 1 byte ... ... ... 2 bytes


Sub - Request Reference Type (06)

Table Number

Starting Address

Word Count

Data Word 1

... Data Word N

1 byte 2 bytes 2 bytes 2 bytes 2 bytes ... 2 bytes

Byte Count Total number of binary bytes in the message, excluding the Powermeter address, function code, byte count, and error check fields

Reference type Fixed field. Must be 06 Table Number The Powermeter Modbus table number Starting Address Address of the first register to be read in the

table (file) Word Count The number of contiguous words to be written Data Word 1 ... N Data to be written

Response The normal response to a write request is the retransmission of the request.

4.2.7 Function 08 - Loopback Communications Test The purpose of this request is to check the communications link between a specified Powermeter and the PC. Request: Powermeter Address

Function (08)

Diagnostic Code (0)

Data Error Check


Diagnos-tic Code

Designates action to be taken in Loopback test. The protocol supports only Diagnostic Code 0 - return query data.

Data Query data. The data passed in this field will be returned to the master through the Powermeter. The entire message returned will be identical to the message transmitted by the master, field-per-field.


Function (08)

Diagnostic Code (0)

Data Error Check



4.3 Exception Responses The Powermeter sends an exception response when errors are detected in the received message. To indicate that the response is notification of an error, the high order bit of the function code is set to 1. Exception response:

Powermeter Address

Function (high order bit is set to 1)

Exception Code

Error Check

1 byte 1 byte 1 byte 2 bytes

Exception response codes:

01 Illegal function 02 Illegal data address 03 Illegal data value 06 Busy, rejected message. The message was

received without error, but the Powermeter is being programmed from the keypad (only for requests accessing setup registers)

NOTE When the character framing, parity, or redundancy check detect a communication error, processing of the master's request stops. The Powermeter will not act on or respond to the message.

4.4 Powermeter Registers 4.4.1 Data Registers

These registers are used to retrieve a predefined set of the data measured by the Powermeter. All electrical parameters are averaged values over the specified number of the real-time measurements (averaging buffer size, see Table 4-5).

NOTE

In the Modbus application, add a value of 40,001 to the register address appearing in


Table 4-4.

Table 4-4 Data Registers (Modbus table #1) No. Parameter Bytes Add-

ress Read/Write

Unit Scale Con- version

Low High 1 Voltage L1/L12 2 256 R V 0 Vmax LIN3 2 Voltage L2/L23 2 257 R V 0 Vmax LIN3 3 Voltage L3/L31 2 258 R V 0 Vmax LIN3 4 Current L1 2 259 R A 0 Imax LIN3 5 Current L2 2 260 R A 0 Imax LIN3 6 Current L3 2 261 R A 0 Imax LIN3 7 kW L1 2 262 R kW -Pmax Pmax LIN3 8 kW L2 2 263 R kW -Pmax Pmax LIN3 9 kW L3 2 264 R kW -Pmax Pmax LIN3 10 kvar L1 2 265 R kvar -Pmax Pmax LIN3 11 kvar L2 2 266 R kvar -Pmax Pmax LIN3 12 kvar L3 2 267 R kvar -Pmax Pmax LIN3 13 kVA L1 2 268 R kVA -Pmax Pmax LIN3 14 kVA L2 2 269 R kVA -Pmax Pmax LIN3 15 kVA L3 2 270 R kVA -Pmax Pmax LIN3 16 Power factor L1 2 271 R -1.00 1.00 LIN3 17 Power factor L2 2 272 R -1.00 1.00 LIN3 18 Power factor L3 2 273 R -1.00 1.00 LIN3 19 Power factor

total 2 274 R -1.00 1.00 LIN3

20 kW total 2 275 R kW -Pmax Pmax LIN3 21 kvar total 2 276 R kvar -Pmax Pmax LIN3 22 kVA total 2 277 R kVA -Pmax Pmax LIN3 23 Unbalanced

current 2 278 R A 0 Imax LIN3

24 Frequency 2 279 R Hz 45.0 65.0 LIN3 25 Maximum kW

demand 2 280 R/W kW -Pmax Pmax LIN3

26 Accumulated kW demand

2 281 R/W kW -Pmax Pmax LIN3

27 Maximum kVA demand

2 282 R/W kVA -Pmax Pmax LIN3

28 Accumulated kVA demand

2 283 R/W kVA -Pmax Pmax LIN3

29 Maximum ampere demand L1

2 284 R/W A 0 Imax LIN3


No. Parameter Bytes Add- ress

Read/Write

Unit Scale Con- version

Low High 30 Maximum

ampere demand L2


31 Maximum ampere demand L3


32 +kWh net (low)

2 287 R/W kWh 0 9999 NONE

33 +kWh net (high)

2 288 R/W kWh 0 999 x104

34 -kWh net (low)

2 289 R/W kWh 0 9999 NONE

35 -kWh net (high)

2 290 R/W kWh 0 99 x104

36 +kvarh net (low)

2 291 R/W kvarh 0 9999 NONE

37 +kvarh net (high)

2 292 R/W kvarh 0 999 x104

38 -kvarh net (low)

2 293 R/W kvarh 0 9999 NONE

39 -kvarh net (high)

2 294 R/W kvarh 0 99 x104

40 N/A 2 295 R 41 N/A 2 296 R 42 N/A 2 297 R 43 N/A 2 298 R 44 N/A 2 299 R 45 N/A 2 300 R 46 kVAh (low) 2 301 R/W kVAh 0 9999 NONE 47 kVAh (high) 2 302 R/W kVAh 0 999 x104 48 kW demand 2 303 R kW -Pmax Pmax LIN3 49 kVA demand 2 304 R kVA -Pmax Pmax LIN3 50 Power factor at

max. kVA demand

2 305 R -1.00 1.00 LIN3

Registers indicated by an N/A mark are read as zeros. The parameter limits are as follows:

Vmax = 660 [V] if PT Ratio = 1.0 and Vmax = 144*PT Ratio [V] if PT ratio > 1.0, for the instruments with 660 V input option



Imax = 1.2 * CT primary current [A] Pmax = (Imax * Vmax * 3)/1000 [kW] if wiring mode is 4L-N Pmax = (Imax * Vmax * 2)/1000 [kW] if wiring mode is 4L-L, 3-

OP, or 3DIR Positive energy readings Negative energy readings These registers are actual for the PM170E/170M only. In the

PM170, they are read as zeros. These registers are actual for the PM170M only. Addressing of

registers 295 through 305 in the PM170/170E will result in a negative response.

NOTES

Writing a zero to one of registers 280 through 286 causes reset of all maximum demands. In the PM170/170E, writing a zero to registers 287-294 causes reset of the corresponding energy register. In the PM170M, writing a zero to one of registers 287-294, 301-302 causes reset of all energy registers.

The voltage parameters throughout the protocol can represent line-to-neutral or line-to-line voltages, depending on the wiring mode selected in the Powermeter. When a 4L-N wiring mode is selected, they will be line-to-neutral voltages, and when another configuration is selected, they will be line-to-line voltages.

• In 3-wire connection schemes, unbalanced current and the phase readings for power factor, active power, and reactive power will be zeros, because they have no meaning. Only the total three-phase power values can be used.

4.4.2 Basic Setup Registers These registers are used to access the basic setup parameters. The values are read and written without conversion. In the event that the modulus field is not equal to 1, the value received from the Powermeter must be multiplied by the


modulus. When written, such a number should be divided by the modulus.


Table 4-5 Basic Setup Registers (Modbus table #9) Parameter Bytes Add-

ress Read/ write

Unit Range Mod-ulus

Wiring mode 2 2304 R/W 0 = 3OP, 1 = 4L-N, 2 = 3DIR, 3 = 4L-L

1

PT ratio 2 2305 R/W 10 to 65000 10-1 CT primary current

2 2306 R/W A 1 to 50000 1

Power demand period

2 2307 R/W min 1,2,5,10,15,20,30,60 min, 255 = external synchronization

1


2 2308 R/W sec 0 to 1800 0 = measuring peak currents

1


2 2309 R/W 8, 32 1


2 2310 R/W 0 = disable, 1 = enable

1

These registers are used to retrieve the current Powermeter status. Writing a value of 65535 into register 2560 will cause the Powermeter to restart (as at power up).

Table 4-6 Powermeter Status Registers (Table #10)

Parameter Bytes Address Read/write

Unit Range

Powermeter reset register

2 2560 R/W 0 (when read) 65535 (when written) = reset Powermeter

Keypad status 2 2561 R See Table 4-7 N/A 2 2562 R N/A 2 2563 R N/A 2 2564 R Firmware version number

2 2565 R 0-65535


Table 4-7 Keypad Status Bit number Description 0 Up key status 1 Enter key status 2 Select key status 3 Down key status

Bit meaning: 0 = key released, 1 = key pressed

4.4.3 Real Time Clock Registers These registers allow the user to read or update the Powermeter's RTC.

Table 4-8 RTC registers Parameter Bytes Address Read/

write Range

Second 2 4352 R/W 0-59 Minute 2 4353 R/W 0-59 Hour 2 4354 R/W 0-23 Day of month 2 4355 R/W 1-31 Month 2 4356 R/W 1-12 Year 2 4357 R/W 0-99

36 Chapter 5 DNP V3.00 Communications Protocol

Chapter 5 DNP V3.00 Communications Protocol 5.

5.1 DNP Protocol 5.1.1 Introduction

DNP V3.00 (Distributed Network Protocol) is an open standard designed by Harris Control Division. DNP defines a command-response method of communicating digital information between a master and slave device. Detailed information regarding DNP V3.00 is available in the “Basic 4 Document Set” which can obtained from the DNP User Group.

5.1.2 PM170 Deviation from Standard The Series PM170 Powermeters do not support unsolicited requests or hardware collision avoidance.

The data link layer differs from the Basic 4 specifications because of the master-slave relationship between devices. When the Powermeter receives a request, no further requests can be sent until after the Powermeter makes the appropriate response.

The Series PM170, like most devices, retrieves data from the instrument by executing a directed (non-broadcast) Read of all class 0 objects (object 60, variation 1, qualifier 6). However, Analog Inputs and Counters are sent without flags. Analog Output Status values are sent with flags which indicate just ONLINE.

Chapter 5 DNP V3.00 Communications Protocol 37

5.1.3 DNP Request/Response Overview The Series PM170 DNP implementation supports a wide variety of messages. The most common method to extract information from the Powermeter is to issue a Read class 0 request. The instrument responds with the value of all Analog Inputs (variation 3), Counters (variation 5) and Analog Output Status (variation 1). The PM170 executes the energy clear function and demands resets using the Direct Operate (or Direct Operate No Acknowledge) command to points 0 and 1 of the Control Relay Output Block object. The setup parameters can be changed by issuing the Direct Operate (or Direct Operate No Acknowledge) command to points 0 through 6 of the Analog Output Block object. The DNP functions Write and Cold Restart are also supported by the Series PM170. Refer to Appendix A for specific requests and responses. Appendix B contains the standard DNP Device Profile Document.

The Powermeter attempts to respond with the same object variation and qualifier as those in the request. Exceptions to this rule include changing variation 0 to a specific variation and changing qualifier code 6 to 1.

If the Powermeter receives an invalid request, it sets the internal indication to the error code.

5.2 DNP Interface 5.2.1 General

This section describes a LEVEL 1 DNP V3.00 communication protocol implemented between a master station and a slave Powermeter. A DNP device (RTU, Computer, etc.) has an address in the range of 0 to 65535, and it is this address that allows a master to selectively request data from any other device. DNP uses the address 65535 for broadcast function. A broadcast request never generates a DNP response.


The DNP implementation in the Series PM170 conforms to all Harris IED implementation guidelines. All data items that are available from the Powermeter can be obtained via the DNP Read class 0 command. Individual items can also be read using the Read Analog Input, Read Counter or Read Analog Output Status commands.

The Energy values can be reset to zero by issuing the Direct Operate (or Direct Operate No Acknowledge) command to point 0 of the Control Relay Output Block object. The request must use the parameters to Pulse On for TIME ON 1 millisecond and TIME OFF 0 millisecond.

The Demand values can be reset to zero by issuing the same Direct Operate (or Direct Operate No Acknowledge) command to another point of this object. The point 1 is used to reset the Maximum Ampere Demand.

The setpoint parameters can be changed by issuing the Direct Operate (or Direct Operate No Acknowledge) command using the Analog Output Block object.

5.2.2 DNP Address The instrument on a DNP link must have a unique address. The Series PM170 Powermeters allow one of 256 addresses to be selected. The selectable addresses have a range of 0-255.

5.2.3 Transaction Timing To allow the master to switch the communication link, it is guaranteed that the Powermeter minimum response time be at least 3.5 character time (depending on the baud rate) and at least 5 ms.

Table 5-1 shows the actual response time measured at 9600 bps:

Table 5-1 Response Time No.

Parameters Typical response time,

ms Maximum response

time, ms


1 15 27 5 22 36

10 29 45 Class 0 (34) (34 points)

66 85

Note that Direct Operate (or Direct Operate No Acknowledge) requests for reset energy/demand and setpoint changing are immediately confirmed.

5.2.4 Object Format The Series PM170 uses two objects which correspond to instrument measurements. There are Counter (object 20, variations 5 and 6) and Analog Input (object 30, variations 3 and 4).

The Series PM170 Powermeters support a response when a value is requested as a variation 0 and will respond as if the requested variation was for a 32 bit Counter or 32 bit Analog Input or 32 bit Analog Output Status. Class 0 reads are treated as a request for all Analog Input , Counter and Analog Output Status points.

5.3 Series PM170 Registers 5.3.1 Data Registers

These registers are used to retrieve a predefined set of the data measured by the Powermeter. All electrical parameters are averaged values over the specified number of the real-time measurements (see Table 3-5 for the averaging buffer size).


Table 5-2 Input Data Parameters Object/

Var Parameter Object/

Point Unit Value range Note

30:3 Voltage L1/L12 AI:0 V 0 to Vmax 30:3 Voltage L2/L23 AI:1 V 0 to Vmax 30:3 Voltage L3/L31 AI:2 V 0 to Vmax 30:3 Current L1 AI:3 A 0 to Imax 30:3 Current L2 AI:4 A 0 to Imax 30:3 Current L3 AI:5 A 0 to Imax 30:3 kW L1 AI:6 kW -Pmax to Pmax 30:3 kW L2 AI:7 kW -Pmax to Pmax 30:3 kW L3 AI:8 kW -Pmax to Pmax 30:3 kvar L1 AI:9 kvar -Pmax to Pmax 30:3 kvar L2 AI:10 kvar -Pmax to Pmax 30:3 kvar L3 AI:11 kvar -Pmax to Pmax 30:3 kVA L1 AI:12 kVA 0 to Pmax 30:3 kVA L2 AI:13 kVA 0 to Pmax 30:3 kVA L3 AI:14 kVA 0 to Pmax 30:4 Power factor L1 AI:15 -99 to 100 × 0.01 30:4 Power factor L2 AI:16 -99 to100 × 0.01 30:4 Power factor L3 AI:17 -99 to100 × 0.01 30:4 Power factor total AI:18 -99 to100 × 0.01 30:3 kW total AI:19 kW -Pmax to Pmax 30:3 kvar total AI:20 kvar -Pmax to Pmax 30:3 kVA total AI:21 kVA 0 to Pmax 30:3 Unbalanced

current AI:22 A 0 to Imax

30:4 Frequency AI:23 Hz 450 to 650 × 0.1 30:3 Maximum kW

demand AI:24 kW 0 to Pmax

30:3 Accumulated kW demand

AI:25 kW 0 to Pmax

30:3 Maximum kVA demand

AI:26 kVA 0 to Pmax

30:3 Accumulated kVA demand

AI:27 kVA 0 to Pmax

30:3 Maximum ampere demand L1

AI:28 A 0 to Imax


AI:29 A 0 to Imax


Object/ Var

Parameter Object/Point

Unit Value range Note


AI:30 A 0 to Imax

30:3 kW demand AI:31 kW 0 to Pmax 30:3 kVA demand AI:32 kVA 0 to Pmax 30:4 Power factor at

max. kVA demand

AI:33 -99 to 100 × 0.01

20:5 kWh net CT:0 kWh -999999 to 9999999 20:5 N/A CT:1 20:5 kvarh net CT:2 kvarh -999999 to 9999999 20:5 kVAh CT:3 kVAh 0 to 9999999

AI indicates Analog Input point, CT Counter point. Registers indicated by an N/A mark are read as zeros.

The parameter limits are as follows: Vmax = 660 [V] if PT Ratio = 1.0 and Vmax = 144*PT Ratio

[V] if PT ratio > 1.0, for the instruments with 660 V input option


Imax = 1.2 * CT primary current [A] Pmax = (Imax * Vmax * 3)/1000 [kW] if wiring mode is 4L-N Pmax = (Imax * Vmax * 2)/1000 [kW] if wiring mode is

4L-L, 3-OP, or 3DIR These registers are actual for the PM170E/170M only. In the PM170, those are read as zeros.

These registers are actual for the PM170M only. Addressing of Points 31 through 33 in the PM170/170E will result in a negative response.

NOTES The voltage parameters throughout the protocol can represent line-to-neutral or line-to-line voltages, depending on the wiring mode selected in the Powermeter. When a 4L-N wiring mode is selected, they will be line to neutral voltages, and when another configuration is selected, they will be line-to-line voltages.


In 3-wire connection schemes, unbalanced current and the phase readings for power factor, active power, and reactive power will be zeros, because they have no meaning. Only the total three-phase power values can be used.

5.3.2 Basic Setup Registers These registers are used to access the basic setup parameters.

The values are read and written without conversion. In the event that the modulus field is not equal to 1, the value received from the Powermeter must be multiplied by the modulus. When written, such a number should be divided by the modulus.

Table 5-3 Basic Setup Registers

Object/ Variation

Parameter Object/ Point

Range Note

40:2 (read) 41:2 (write)

Wiring mode AO:0 0 = 3OP 1 = 4L-N 2 = 3DIR 3 = 4L-L

40:1 (read) 41:1 (write)

PT ratio AO:1 10 to 65000 × 0.1

40:1 (read) 41:1 (write)

CT primary current

AO:2 1 to 50000 A

40:2 (read) 41:2 (write)

Power demand period

AO:3 1,2,5,10,15,20,30,60 min 255 = external synchronization

40:2 (read) 41:2 (write)


AO:4 0 to 1800 sec 0 = measuring peak currents

40:2 (read) 41:2 (write)


AO:5 8, 32

40:2 (read) 41:2 (write)


AO:6 0 = disable, 1 = enable

AO indicates Analog Output Status (Read) and Analog Output Block (Write) points.

The register shown in Table 5-4 is used to retrieve the firmware version number.


Table 5-4 Powermeter Status Register

Object/ Variation


Read/ Write

Range

30:4 Firmware version number

AI:1024 Read 0-65535

30:4 Instrument option 1 AI:1025 Read 0-FFFF 30:4 Instrument option 2 AI:1026 Read 0-FFFF

AI indicates Analog Input points.

5.3.3 Resetting Energy and Demands The Energy value can be reset to zero by issuing the Direct Operate (or Direct Operate No Acknowledge) command using the Control Relay Output Block object to point 0. The request must use the parameters to Pulse On for Time ON 1 millisecond and Time OFF 0 millisecond.

The Ampere Demands value can be reset by issuing the same Direct Operate (or Direct Operate No Acknowledge) command to point 1.

Table 5-5 Reset Energy/Demands Registers

Object/ Var


Read/ Write

Description

12:1 Energy CROB:0 Write PULSE ON Time ON 150ms Time OFF 0

12:1 Ampere Demands

CROB:1 Write PULSE ON Time ON 150ms Time OFF 0

CROB indicates Control Relay Output Block point.

44 Appendix A DNP Application Messages

Appendix A DNP Application Messages 6.

The Powermeter is a DNP IED responding to external DNP Master requests. Table A.-1 describes the Series PM170 application level responses to external requests, including object variations, functions, codes and qualifiers supported by the instrument. The object and formats are detailed in the DNP Basic 4 Documentation Set.

Table A-1 Application Responses

OBJECT REQUEST RESPONSE

Obj Var Description Func. Code

Qual. Code

Func. Code

Qual. Code

12 1 Control Relay Output Block 5 A 129 C 12 1 Control Relay Output Block 6 A None N/A 20 0 Counter (responds like 20:5) 1 06 129 01 20 5 32-bit Binary Counter without flag 1 A 129 C

20 6 16-bit Binary Counter without flag 1 A 129 C

30 0 Analog Input (respond like 30:3) 1 06 129 01 30 3 32-bit Analog Input without flag 1 A 129 C 30 3 16-bit Analog Input without flag 1 A 129 C 40 0 Analog Output Status (respond

like 40:1) 1 06 129 01

40 1 32-bit Analog Output Status 1 A 129 C 40 2 16-bit Analog Output Status 1 A 129 C 41 1 32-bit Analog Output Block 5 A 129 C 41 2 16-bit Analog Output Block 5 A 129 C 41 1 32-bit Analog Output Block 6 A None N/A 41 2 16-bit Analog Output Block 6 A None N/A

Appendix A DNP Application Messages 45

OBJECT REQUEST RESPONSE

Obj Var Description Func. Code

Qual. Code

Func. Code

Qual. Code

60 1 Class 0 1 06 129 01 60 2 Class 1 1 B 129 N/R 60 3 Class 2 1 B 129 N/R 60 4 Class 3 1 B 129 N/R 80 1 Internal indication (point 7 only) 2 D 129 N/A

N/A N/A Cold Restart (respond obj. 52:2) 13 N/A 129 07

Qualifier Hex Codes for each category: A - 00,01,03,04,07,17,27,08,18,28 B - 06,07,08 C - Qualifier echo D - 00,01,03,04,17,27,18,28 N/A - Not Available, N/R - Null Respond

46 Appendix B DNP Device Profile

Appendix B DNP Device Profile

DNP V3.00

DEVICE PROFILE DOCUMENT

This document must be accompanied by a table having the following headings:

Object Group Request Function Codes Response Function Codes Object Variation Request Qualifiers Response Qualifiers

Object Name (optional)

Vendor Name: SATEC Ltd.

Device Name: Powermeter Series PM170

Highest DNP Level Supported:

For Requests L1

For Responses L1

Device Function:

Master Slave

Instrument supports READs of each object using either all points (Qualifier = 6) or specific points using qualifier defined in Basic 4 Documentation Set: 00, 01, 03, 04, 07, 17, 27, 08, 18, 28. Control Relay Block (Energy and Demand Reset Command) requires specific parameters described in this manual.

Maximum Data Link Frame Size (octets):

Transmitted 292 Received 292

Maximum Application Fragment Size (octets):

Transmitted 249 Received 249

Maximum Data Link Re-tries:

None Fixed at____________________ Configurable, range ___ to_____

Maximum Application Layer Re-tries:

None Configurable, range ____

to _______

Appendix B DNP Device Profile 47

(Fixed is not permitted)


Device Profile Document (continued)

Requires Data Link Layer Confirmation: Never

Always

Sometimes If 'Sometimes', when? _________________________

Configurable If 'Configurable', how? _________________________

Requires Application Layer Confirmation:

Never

Always (not recommended)

When reporting Event Data (Slave devices only)

When sending multi-fragment responses (Slave devices only)

Sometimes If 'Sometimes', when? _________________________

Configurable If 'Configurable', how? _________________________

Timeouts while waiting for:

Data Link Confirm None Fixed at ______ Variable Configurable

Complete Appl. Fragment None Fixed at ______ Variable Configurable

Application Confirm None Fixed at ______ Variable Configurable

Complete Appl. Response None Fixed at ______ Variable Configurable

Others _______________________________________________________________

Attach explanation if 'Variable' or 'Configurable' was checked for any timeout

Appendix B DNP Device Profile 49


Sends/Executes Control Operations:

WRITE Binary Outputs Never Always Sometimes Configurable

SELECT/OPERATE Never Always Sometimes Configurable

DIRECT OPERATE Never Always Sometimes Configurable

DIRECT OPERATE -

NO ACK Never Always Sometimes Configurable

Count > 1 Never Always Sometimes Configurable

Pulse On Never Always Sometimes Configurable

Pulse Off Never Always Sometimes Configurable

Latch On Never Always Sometimes Configurable

Latch Off Never Always Sometimes Configurable

Queue Never Always Sometimes Configurable

Clear Queue Never Always Sometimes Configurable

Attach explanation if 'Sometimes' or 'Configurable' was checked for any operation.

Reports Binary Input Change Events when no specific variation requested:

Never

Only time-tagged

Only non-time-tagged

Configurable to send both, one or the other (attach explanation)

Reports time-tagged Binary Input Change Events when no specific variation requested:

Never

Binary Input Change With Time

Binary Input Change With Relative Time

Configurable (attach explanation)



Sends Unsolicited Responses:

Never


Only certain objects

Sometimes (attach explanation)

ENABLE/DISABLE UNSOLICITED

Function codes supported

Sends Static Data in Unsolicited Responses:

Never

When Device Restarts

When Status Flags Change

No other options are permitted.

Default Counter Object/Variation:

No Counters Reported


Default Object 20

Default Variation 5

Point-by-point list attached

Counters Roll Over at:

No Counters Reported


16 Bits

32 Bits

Other Value Counters

-999999 to 9999999 #0,1

0 to 9999999 #2

Point-by-point list attached

Sends Multi-Fragment Responses: Yes No

51

INDEX

address field, 18 ASCII, 1, 2, 6, 8, 9 buffer, 3, 5, 10, 29, 38 Communication Mode, 4 communication protocol, 1, 21 computer mode, 1 CRC, 20 CRC-16, 19, 20 data conversion, 21 data field, 8, 9, 19 DNP address, 37 DNP profile, 45, 46, 47, 48 DNP registers, 41 error check field, 19, 25, 28 exception response, 29 flow control, 3, 5 framing, 8, 9, 29 function field, 18

handshaking, 3, 4, 5, 6 Modbus, 1, 17, 21, 23 modbus protocol, 17 Modbus protocol, 2 modbus registers, 21, 22, 23,

24, 25, 26, 27, 29, 32 parity, 17, 19, 29 print mode, 1, 5 Print Mode, 1, 2 real time clock, 16, 34 response time, 2 response time, DNP, 37 rs-232, 3 RS-232, 1, 2 RS-422, 1, 2, 8 RS-485, 2, 4, 8 rtu frame, 18 RTU frame, 18

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