Satec PM171 series Reference Manual
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Satec PM171 series Reference Manual

Modbus communications protocol powermeter
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Series PM171
Powermeters
Modbus
Communications
Protocol
Reference Guide
BG0236 Rev. A2

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Summary of Contents for Satec PM171 series

  • Page 1 Series PM171 Powermeters Modbus Communications Protocol Reference Guide BG0236 Rev. A2...
  • Page 2 SERIES PM171 POWERMETERS COMMUNICATIONS Modbus Communications Protocol REFERENCE GUIDE...
  • Page 3 Every effort has been made to ensure that the material herein is complete and accurate. However, the manufacturer is not responsible for any mistakes in printing or faulty instructions contained in this book. Notification of any errors or misprints will be received with appreciation. For further information regarding a particular installation, operation or maintenance of equipment, contact the manufacturer or your local representative or distributor.

  • Page 4: Table Of Contents

    Table of Contents 1 GENERAL ......................4 2 MODBUS FRAMING ..................5 2.1 Transmission Mode......................5 2.2 The RTU Frame Format ....................5 2.3 Address Field ........................5 2.4 Function Field........................5 2.5 Data Field...........................6 2.6 Error Check Field .......................6 3 MODBUS MESSAGE FORMATS..............7 3.1 Function 03 - Read Multiple Registers ................7 3.2 Function 04 - Read Multiple Registers ................7 3.3 Function 06 - Write Single Register ...................7 3.4 Function 16 - Write Multiple Registers ................8...

  • Page 5: General

    1 GENERAL This document specifies a subset of the Modbus serial communications protocol used to transfer data between a master computer station and the PM171. The document provides the complete information necessary to develop a third-party communications software capable of communication with the Series PM171 Powermeters.

  • Page 6: Modbus Framing

    2 MODBUS FRAMING 2.1 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 instrument communications.

  • Page 7: Data Field

    2.5 Data Field The data field contains information needed by the instrument to perform a specific function, or data collected by the instrument in response to a query. IMPORTANT Fields composed of two bytes are sent in the order high byte first, low byte second. 2.6 Error Check Field The error check field contains the Cyclical Redundancy Check (CRC) word.

  • Page 8: Modbus Message Formats

    3 MODBUS MESSAGE FORMATS 3.1 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 Instrument Function Starting Word Count Error Check Address (03) Address 1 byte 1 byte...

  • Page 9: Function 16 - Write Multiple Registers

    3.4 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 Instrument Function Starting Word Byte Address (16) Address Count Count 1 byte 1 byte...

  • Page 10: Exception Responses

    3.6 Exception Responses The instrument 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 Instrument Function (high Exception...

  • Page 11: Protocol Implementation

    4 PROTOCOL IMPLEMENTATION 4.1 Modbus Register Addresses The PM171 Modbus registers are referred to by using addresses in the range of 0 to 65535. From within the Modbus applications, the PM171 Modbus registers can be accessed by simulating holding registers of the Modicon 584, 884 or 984 Programmable Controller, using a 5-digit “4XXXX” or 6-digit “4XXXXX”...

  • Page 12: 32-Bit Modulo 10000 Format

    the least significant decimal digit). To get an actual fractional number with specified precision, scale the register value with the given multiplier. To write a fractional number into the register, divide the number by the given multiplier. 4.2.2 32-bit Modulo 10000 Format The short energy registers 287-294, and 301-302 are transmitted in two contiguous 16-bit registers in modulo 10000 format.

  • Page 13: Configuring And Accessing Log Files

    Table 4-2 User Assignable Register Map Register contents Register Size, byte Direction Range Register address for user data 0 240 to 65535 Register address for user data 1 240 to 65535 Register address for user data 2 240 to 65535 Register address for user data 119 239 240 to 65535 4.4 Configuring and Accessing Log Files...

  • Page 14: Powermeter Registers Description

    5 POWERMETER REGISTERS DESCRIPTION 5.1 Basic Data Registers Table 5-1 Basic Data Registers Parameter Register Size, Direc- Unit Scale Con- byte tion High version Voltage L1/L12 Vmax LIN3 Voltage L2/L23 Vmax LIN3 Voltage L3/L31 Vmax LIN3 Current L1 Imax LIN3 Current L2 Imax LIN3...

  • Page 15: Basic Setup Registers

    Parameter Register Size, Direc- Unit Scale Con- byte tion High version Current TDD L1 0.1% 100.0 LIN3 Current TDD L2 0.1% 100.0 LIN3 Current TDD L3 0.1% 100.0 LIN3 The parameter limits are as follows: Imax (20% over-range) = 1.2 × CT primary current [A] Direct wiring (PT Ratio = 1): Vmax (690 V input option) = 828.0 V Vmax (120 V input option) = 144.0 V...

  • Page 16: User Selectable Options Setup Registers

    5.3 User Selectable Options Setup Registers Table 5-3 User Selectable Options Registers Parameter Register Size, Direc- Range byte tion Power calculation mode 2376 0 = using reactive power, 1 = using non-active power 0 = 1×10 4 Energy roll value (E) 2377 1 = 1×10 5 2 = 1×10 6...

  • Page 17: Communications Setup Registers

    5.4 Communications Setup Registers Table 5-4 Communications Setup Registers Parameter Register Size, Direc- Range byte tion Reserved 2344 Read as 65535 Interface 2345 0 = RS-232 1 = RS-422 2 = RS-485 Address 2346 1 to 247 Baud rate 2347 0 = 110 bps 1 = 300 bps 2 = 600 bps...

  • Page 18: Instrument Status Registers

    5.6 Instrument Status Registers Table 5-6 Instrument Status Registers Parameter Register Size, Direc- Unit Range byte tion Instrument reset 2560 0 (when read) register 65535 (when written) = reset the instrument Reserved 2561 Read as 0 Relay status 2562 see Table 5-7 Reserved 2563 Read as 0...
  • Page 19 Parameter Register Size, Direction Value range byte Setpoint alarm status 3474 see Table 5-15 Self-check alarm status 3475 see Table 5-16 Reserved 3476- Read as 0 3484 Battery status 3485 0 = low, 1 = normal Table 5-10 Relay Status Description Relay #1 status Relay #2 status...
  • Page 20 Table 5-14 Data Log Status Description New data log #1 New data log #2 New data log #3 New data log #4 New data log #5 New data log #6 New data log #7 New data log #8 4-15 Not used (permanently set to 0) Bit meaning: 0 = no new logs, 1 = new log recorded (the new log flag is reset when the user reads the first log record after the flag has been set) Table 5-15 Setpoint Alarm Status...

  • Page 21: Memory Status Registers

    5.8 Memory Status Registers Table 5-17 Memory Status Registers Parameter Register Size, Direction Range byte Total memory size, Byte 3506, 3507 524288 Free memory size, Byte 3508, 3509 0 - 524288 The total number of event log records 3510 0 - 65535 The total number of data log #1 records 3511 0 - 65535...
  • Page 22 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High Pulse counter #3 7060 13060-13061 2562 999999 7061 Pulse counter #4 7062 13062-13063 2563 999999 7063 Real-time values per phase Voltage L1/L12 7136 LIN3 13312-13313 3072 Vmax Voltage L2/L23 7137 LIN3 13314-13315...
  • Page 23 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High kVA L1 7348 LIN3 13976-13977 4364 1kVA Pmax kVA L2 7349 LIN3 13978-13979 4365 1kVA Pmax kVA L3 7350 LIN3 13980-13981 4366 1kVA Pmax Power factor L1 7351 LIN3 13982-13983 4367...
  • Page 24 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High Predicted sliding window 7556 LIN3 14632-14633 5652 1kVA Pmax kVA demand PF (import) at maximum 7557 LIN3 14634-14635 5653 0.001 -1.000 1.000 kVA sliding window demand Block kW export demand 7558 LIN3 14636-14637 5654...
  • Page 25 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High Current L3 8301 LIN3 17034-17035 10501 Imax kW L1 8302 LIN3 17036-17037 10502 -Pmax Pmax kW L2 8303 LIN3 17038-17039 10503 -Pmax Pmax kW L3 8304 LIN3 17040-17041 10504 -Pmax Pmax kvar L1...
  • Page 26 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High Max. ampere demand L3 8861 LIN3 18826-18827 14085 Imax Reserved 8862 LIN3 18828-18829 14086 Reserved 8863 LIN3 18830-18831 14087 Reserved 8864 LIN3 18832-18833 14088 Max. sliding window kW 8865 LIN3 18834-18835...
  • Page 27 Parameter 16-bit Register 32-bit Data Dir. Unit Range/Scale Reg. Conv. Register High Tariff #2 register 9298 20226-20227 16897 9299 Tariff #16 register 9326 20254-20255 16911 9327 TOU energy register #7 (E) Tariff #1 register 9336 20352-20353 17152 9337 Tariff #2 register 9338 20354-20355 17153...

  • Page 28: Analog Output Setup Registers

    5.10 Analog Output Setup Registers Table 5-19 Analog Output Allocation Registers Channel Registers (see Table 5-20) Channel #1 3148-3150 Channel #2 3151-3153 Table 5-20 Analog Channel Allocation Registers Parameter Offset Size, byte Direction Range Output parameter ID see Table 5-23 Zero scale (0-4 mA) see Table 5-23 Full scale (1/20 mA)
  • Page 29 Table 5-23 Analog Output Parameters Output parameter Data Size, Unit Scale Con- byte High version None NONE None Real-time values per phase Voltage L1/L12 3072 Vmax LIN3 Voltage L2/L23 3073 Vmax LIN3 Voltage L3/L31 3074 Vmax LIN3 Current L1 3075 Imax LIN3 Current L2...

  • Page 30: Digital Inputs Allocation Registers

    5.12 Digital Inputs Allocation Registers Table 5-24 Digital Inputs Allocation Registers Parameter Register Size, Direction Range byte Status inputs allocation mask 3292 See Table 5-25 Pulse inputs allocation mask 3293 See Table 5-25 Not used 3294 Read as 0 External demand synchronization input mask (E) 3295 See Table 5-25 Writing to these locations is ignored.
  • Page 31 Table 5-31 Setpoint Setup Registers Parameter Offset Size, byte Range Trigger ID see Table 5-29 Action see Table 5-30 Operate delay 0-9999 (x 0.1 sec) Release delay 0-9999 (x 0.1 sec) Operate limit see Table 5-29 Release limit see Table 5-29 The setpoint is disabled when the first trigger ID is set to NONE.
  • Page 32 Trigger parameter Trigger Size, Unit Limit/scale Con- byte High version High pulse counter #4 2563 NONE Time/Date parameters (E) 2818 1=Sun 7=Sat NONE Day of week 2819 NONE Year 2820 NONE Month 2821 NONE Day of month 2822 NONE Hour 2823 NONE Minutes...

  • Page 33: Pulsing Setpoints Registers

    Trigger parameter Trigger Size, Unit Limit/scale Con- byte High version High sliding window kVA demand (E) 5643 1kVA Pmax LIN3 High accumulated kW import demand (E) 5647 Pmax LIN3 High accumulated kVA demand (E) 5649 1kVA Pmax LIN3 High predicted kW import demand (E) 5650 Pmax LIN3...

  • Page 34: Relay Operation Control Registers

    Table 5-32 Pulsing Setup Registers Parameter Offset Size, Direction Range byte Output parameter ID see Table 5-33 Number of unit-hours per pulse 1-9999 Table 5-33 Pulsing Output Parameters Pulsing parameter None kWh import kWh export kvarh import kvarh export kvarh total (absolute) kVAh total 5.16 Relay Operation Control Registers These registers allow the user to manually override setpoint relay operations.

  • Page 35: Log Memory Partitions Setup Registers

    Table 5-38 Digital Inputs Identifiers Discrete input Not allocated Digital input # 1 Digital input # 2 5.18 Log Memory Partitions Setup Registers Table 5-39 Memory Partitions Setup Registers Partition Memory partition Setup registers Number (see Table 5-40) Event log 3660-3665 Data log #1 3668-3673...

  • Page 36: Data Log Setup Registers

    5.19 Data Log Setup Registers Table 5-42 Data Log Setup Registers Partition Registers (see Table 5-43) Data log #1 1792-1807 Data log #2 1808-1823 Data log #3 1824-1839 Data log #4 1840-1855 Data log #5 1856-1871 Data log #6 1872-1887 Data log #7 1888-1903 Data log #8...
  • Page 37 Table 5-48 Event Log Window Registers Parameter Offset Size, Direction Range byte Second 0-59, 97 = record corrupted 98 = no more events 99 = no events logged Minute 0-59 Hour 0-23 1-31 Month 1-12 Year 0-99 Event cause see Table 5-46 Event origin see Table 5-46 Log value (16-bit...

  • Page 38: Data Log Registers

    5.21 Data Log Registers Data log records are read via a data log window, one for each data log partition. Reading from this window always returns the next record logged in the partition. All registers within one window must be read at once using a single request.

  • Page 39: Real Time Clock Registers

    Table 5-51 Min/Max Log Windows Registers Min/Max log window Registers (see Table 5-52) Min/Max log window #1 4174-4181 Min/Max log window #2 4182-4189 Min/Max log window #3 4190-4197 Min/Max log window #4 4198-4205 Min/Max log window #5 4206-4213 Min/Max log window #6 4214-4221 Min/Max log window #7 4222-4229...

  • Page 40: Tou System Registers Setup

    5.24 TOU System Registers Setup Table 5-55 TOU System Setup Registers TOU system register Setup registers (see Table 5-56) TOU energy register #1 4564-4565 TOU energy register #2 4566-4567 TOU energy register #3 4568-4569 TOU energy register #4 4570-4571 TOU energy register #5 4572-4573 TOU energy register #6 4574-4575...

  • Page 41: Tou Daily Profiles Registers

    5.25 TOU Daily Profiles Registers Table 5-59 TOU Daily Profiles Registers TOU daily profile Setup registers (see Table 5-60) TOU daily profile #1 2048-2063 TOU daily profile #2 2064-2079 TOU daily profile #3 2080-2095 TOU daily profile #4 2096-2111 TOU daily profile #5 2112-2127 TOU daily profile #6 2128-2143...

  • Page 42: Tou Calendar Registers

    5.26 TOU Calendar Registers Table 5-62 TOU Calendars Registers TOU calendar Calendar month Setup registers (see Table 5-63) TOU calendar #1 January 4368-4375 February 4376-4383 March 4384-4391 April 4392-4399 4400-4407 June 4408-4415 July 4416-4423 August 4424-4431 September 4432-4439 October 4440-4447 November 4448-4455 December...
  • Page 43 NOTES...

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