Yokogawa PR300 User Manual

User’s Manual
Model PR300 Power and Energy Meter Communication Interface
(RS-485 and Ethernet Communications)
IM 77C01E01-10E
IM 77C01E01-10E
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Introduction

This user's manual describes the communication functions of the PR300 power and energy meter and contains information on how to create communication programs.
Hereafter, the PR300 power and energy meter is simply referred to as the PR300. Read the manual carefully to understand the communication functions of the PR300 .
The PR300 has the following communication protocols.
PC link communication protocol
Modbus /RTU and Modbus/ASCII communication protocols
Modbus/TCP communication protocol (for the PR300 with Ethernet communication
function)
PR201 original communication protocol
You are required to have background knowledge of the communication specifications of higher-level devices, their communication hardware, language used for creating communi­cation programs, and so on.
i
Intended Readers
This manual is intended for people familiar with the functions of the PR300, control engi­neers and personnel in charge of maintaining instrumentation and control equipment.
Related Documents
The following user's manuals all relate to the communication functions of the PR300. Read them as necessary.
Model PR300 Power and Energy Meter User's Manual (electronic manual) Document number: IM 77C01E01-01E
Model PR300 Power and Energy Meter Startup Manual <Installation> Document number: IM 77C01E01-02E
Model PR300 Power and Energy Meter Startup Manual <Initial Setup Operations> Document number: IM 77C01E01-03E
These manuals provide information about the procedure of installation, wiring and opera­tion.
Trademark
(1) All the brands or names of Yokogawa Electric's products used in this manual are
either trademarks or registerd trademarks of Yokogawa Electric Corporation.
(2) Ethernet is a registered trademark of XEROX Corporation in the United States. (3) Company and product names that appear in this manual are trademarks or registered
trademarks of their respective holders.
Media No. IM 77C01E01-10E 3rd Edition : Feb. 15, 2007 (YK) All Rights Reserved Copyright © 2006, Yokogawa Electric Corporation
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Documentation Conventions

Symbols
This manual uses the following symbols.
Symbols Used in the Main Text
NOTE
Draws attention to information that is essential for understanding the operation and/or features of the product.
TIP
Gives additional information to complement the present topic.
See Also
ii
Gives reference locations for further information on the topic.
Symbols Used in Figures and Tables
[NOTE]
Draws attention to information that is essential for understanding the features of the product.
[TIP]
Gives additional information to complement the present topic.
[See Also]
Gives reference locations for further information on the topic.
Description of Displays
(1) Some of the representations of product displays shown in this manual may be exag-
gerated, simplified, or partially omitted for reasons of convenience when explaining them.
(2) Figures and illustrations representing the PR300's displays may differ from the real
displays in regard to the position and/or indicated characters (upper-case or lower­case, for example), the extent of difference does not impair a correct understanding of the functions and the proper operations and monitoring of the system.
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Notices

Regarding This User's Manual
(1) This manual should be passed on to the end user. Keep the manual in a safe place. (2) Read this manual carefully to gain a thorough understanding of how to operate this
product before you start using it.
(3) This manual is intended to describe the functions of this product. Yokogawa Electric
Corporation (hereinafter simply referred to as Yokogawa) does not guarantee that these functions are suited to the particular purpose of the user.
(4) Under absolutely no circumstance may the contents of this manual, in part or in whole,
be transcribed or copied without permission.
(5) The contents of this manual are subject to change without prior notice. (6) Every effort has been made to ensure accuracy in the preparation of this manual.
Should any errors or omissions come to your attention however, please contact your nearest Yokogawa representative or our sales office.
(7) The document concerning TCP/IP software has been created by Yokogawa based on
the BSD Networking Software, Release 1 that has been licensed from the University of California.
iii
Regarding Protection, Safety, and Prohibition Against Unauthorized Modification
(1) In order to protect the product and the system controlled by it against damage and
ensure its safe use, be certain to strictly adhere to all of the instructions and precau­tions relating to safety contained in this document. Yokogawa does not guarantee safety if products are not handled according to these instructions.
(2) The following safety symbols are used on the product and/or in this manual.
Symbols Used on the Product and in This Manual
This symbol on the product indicates that the operator must refer to an explanation in the user's manual in order to avoid the risk of injury or death of personnel or damage to the instrument. The manual describes how the operator should exercise special care to avoid electric shock or other dangers that may result in injury or loss of life.
Protective Grounding Terminal This symbol indicates that the terminal must be connected to ground prior to operating
the equipment.
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Force Majeure
(1) Yokogawa does not make any warranties regarding the product except those men-
tioned in the WARRANTY that is provided separately.
(2) Yokogawa assumes no liability to any party for any loss or damage, direct or indirect,
caused by the use or any unpredictable defect of the product.
(3) Be sure to use the spare parts approved by Yokogawa when replacing parts or
consumables. (4) Modification of the product is strictly prohibited. (5) Reverse engineering such as the disassembly or decompilation of software is strictly
prohibited. (6) No portion of the software supplied by Yokogawa may be transferred, exchanged,
leased, or sublet for use by any third party without the prior permission of Yokogawa.
iv
IM 77C01E01-10E
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Model PR300 Power and Energy Meter Communication Interface
Toc-1
(RS-485 and Ethernet Communications)
IM 77C01E01-10E 4th Edition

CONTENTS

Introduction........................................................................................................... i
Documentation Conventions ...............................................................................ii
Notices .................................................................................................................iii
1. Communications Overview
1.1 RS-485 Communication Specifications ......................................................... 1-1
1.2 Ethernet Communication Specifications....................................................... 1-1
2. Setup
2.1 Setup Procedure ............................................................................................. 2-1
2.1.1 Procedure for RS-485 Communication ............................................. 2-2
2.1.2 Procedure for Ethernet Communication ............................................ 2-3
2.1.3 Procedure for Ethernet-Serial Gateway Function .............................. 2-4
2.2 Setting Communication Conditions .............................................................. 2-6
2.2.1 Conditions for RS-485 Communication ............................................. 2-6
2.2.2 Conditions for Ethernet Communication ............................................ 2-8
2.2.3 Conditions for Ethernet-Serial Gateway Function ............................ 2-10
2.3 Wiring for Communication ........................................................................... 2-12
2.3.1 Wiring for RS-485 Communication .................................................. 2-12
2.3.2 Wiring for Ethernet Communication ................................................ 2-13
2.3.3
Wiring for RS-485 Communication for Ethernet-Serial Gateway Function ..
2-14
3. Procedures for Setting PR300 Functions
3.1 Basic Setting ................................................................................................... 3-2
3.1.1 Setting of VT Ratio ............................................................................ 3-2
3.1.2 Setting of CT Ratio............................................................................ 3-3
3.1.3 Setting of Integrated Low-cut Power ................................................. 3-4
3.2 Setting Pulse Output....................................................................................... 3-5
3.2.1 Selection of Measurement Item for Pulse Output .............................. 3-5
3.2.2 Pulse Unit ......................................................................................... 3-6
3.2.3 ON Pulse Width ................................................................................ 3-7
3.3 Setting Analog Output .................................................................................... 3-8
3.3.1 Selection of Measurement Item for Analog Output ............................ 3-8
3.3.2 Upper/Lower Limits of Scaling .......................................................... 3-9
3.4 Demand Setting ............................................................................................ 3-10
3.4.1 Demand Power/Current .................................................................. 3-10
3.4.2 Demand Period................................................................................3-11
3.4.3 Demand Alarm Mask Time .............................................................. 3-12
3.4.4 Demand Power Alarm Point ............................................................ 3-13
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3.4.5 Demand Current Alarm Point .......................................................... 3-14
3.4.6 Demand Alarm Release Function ................................................... 3-15
3.5 Communication Setting ................................................................................ 3-16
3.5.1 Protocol .......................................................................................... 3-16
3.5.2 Baud Rate ...................................................................................... 3-17
3.5.3 Parity .............................................................................................. 3-18
3.5.4 Stop Bit ........................................................................................... 3-19
3.5.5 Data Length .................................................................................... 3-20
3.5.6 Station Number............................................................................... 3-21
3.5.7 IP Address (for Ethernet communication) ........................................ 3-22
3.5.8 Subnet Mask (for Ethernet communication) .................................... 3-23
3.5.9 Default Gateway (for Ethernet communication) ............................... 3-24
3.5.10 Port Number (for Ethernet communication) ..................................... 3-25
3.6 Writing Energy Values .................................................................................. 3-26
3.6.1 Active Energy ................................................................................. 3-26
3.6.2 Regenerative Energy ...................................................................... 3-27
3.6.3 LEAD Reactive Energy ................................................................... 3-28
3.6.4 LAG Reactive Energy ..................................................................... 3-29
3.6.5 Apparent Energy............................................................................. 3-30
3.7 Executing Reset Operations ........................................................................ 3-31
3.7.1 Remote Reset ................................................................................ 3-31
3.7.2 Maximum/Minimum Values Reset ................................................... 3-32
3.7.3 Energy Value All-Reset ................................................................... 3-32
3.7.4 Active Energy Reset ....................................................................... 3-33
3.7.5 Regenerative Energy Reset ............................................................ 3-33
3.7.6 Reactive Energy Reset ................................................................... 3-34
3.7.7 Apparent Energy Reset .................................................................. 3-34
3.8 Setting Control States .................................................................................. 3-35
3.8.1 Integration Start/Stop ..................................................................... 3-35
3.8.2 Optional Integration Start/Stop ........................................................ 3-36
3.8.3 Demand Measurement Start/Stop................................................... 3-37
3.8.4 Confirmation and Release of Demand Alarm State ......................... 3-38
4. PC Link Communication Protocol
4.1 Overview.......................................................................................................... 4-1
4.1.1 Configuration of Command ............................................................... 4-2
4.1.2 Configuration of Response ............................................................... 4-3
4.1.3 Response Error Codes ..................................................................... 4-4
4.1.4 Specifying Broadcast ........................................................................ 4-5
4.2 Command and Response ............................................................................... 4-6
WRD Reads D registers on a word-by-word basis ................................... 4-7
WWR Writes data into D registers on a word-by-word basis..................... 4-8
WRR Reads D registers on a word-by-word basis in random order......... 4-9
WRW WRS
WRM Monitors the D registers on a word-by-word basis ........................ 4-12
INF6 Reads the model, suffix codes, and version information............... 4-13
INF7 Reads the maximum value of CPU ............................................... 4-14
4.3 Communication with Higher-level Devices ................................................. 4-15
4.3.1 Communication with FA-M3 (UT Link Module) ................................ 4-15
Writes data into D registers on a word-by-word basis in random order ...
Specifies the D registers to be monitored on a word-by-word basis ........
4-10 4-11
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5. Modbus/RTU and ASCII Communication Protocols
6. Modbus/TCP Communication Protocol
Toc-3
4.4 Sample Program ........................................................................................... 4-17
4.4.1 Example of BASIC Program for Send and Receive ......................... 4-17
5.1 Overview.......................................................................................................... 5-1
5.1.1 Configuration of Message ................................................................. 5-3
5.1.2 Specifying D Registers...................................................................... 5-4
5.1.3 Checking Errors ................................................................................ 5-4
5.1.4 Configuration of Response ............................................................... 5-7
5.1.5 Specifying Broadcast ........................................................................ 5-9
5.2 Message and Response ............................................................................... 5-10
03 Reads data from multiple D registers ............................................ 5-11
06 Writes data into D register ............................................................. 5-12
08 Performs loop back test................................................................. 5-13
16 Writes data into multiple D registers .............................................. 5-14
6.1 Overview.......................................................................................................... 6-1
6.2 TCP/IP Communication .................................................................................. 6-3
6.3 Network Frame Structure ............................................................................... 6-4
6.3.1 MBAP Header Structure ................................................................... 6-4
6.3.2 PDU Structure .................................................................................. 6-4
6.4 Communication with Higher-level Devices ................................................... 6-5
6.4.1 List of Function Codes ...................................................................... 6-5
6.4.2 Specifying D Registers...................................................................... 6-5
6.4.3 Request and Response .................................................................... 6-6
03 Reads data from multiple D registers .............................................. 6-6
06 Writes data into D register ............................................................... 6-7
08 Performs loop back test................................................................... 6-8
16 Writes data into multiple D registers ................................................ 6-9
6.4.4 Response Error Codes .................................................................... 6-11
6.5 Sample Program ........................................................................................... 6-12
6.5.1 Example of BASIC Program for Send and Receive ......................... 6-12
7. Functions and Usage of D Registers
7.1 Overview of D Registers ................................................................................. 7-1
7.2 Configuration of D Registers.......................................................................... 7-1
7.3 Interpretation of D Register Map Table .......................................................... 7-1
7.4 D Register Map ................................................................................................ 7-2
8. PR201 Original Communication Protocol
8.1 Overview.......................................................................................................... 8-1
8.2 Communication Specifications ...................................................................... 8-1
8.3 Command/Response Format ......................................................................... 8-2
8.4 List of Commands........................................................................................... 8-3
8.5 Command Details............................................................................................ 8-5
Appendix Table of ASCII Codes (Alphanumeric Codes) Revision Information
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1. Communications Overview

1.1 RS-485 Communication Specifications

Protocols available for RS-485 communication interfaces include the PC link com­munication protocol and the Modbus communication protocol.
Table 1.1 RS-485 Communication Specifications
Item Details Connected Device Communication Hardware Compliant Standard
Protocol Specification
Baud Rate Maximum Communication Distance Maximum Number of
Connectable Devices Transmission Method Synchronization Communication Method Communication Cable
2-wire system RS-485 EIA RS-485
PC Link Communication with and without checksum
Modbus Communication (ASCII and RTU modes)
PR201 original communication
2400 bps, 9600 bps, 19200 bps 1200 m
31 2-wire, half-duplex
Start-stop synchronization Non-procedural Shielded twisted pair cable
(AWG24-equivalent size)
A PC installed with a driver for PC link communication and SCADA software, PLC (FA-M3 UT link module), etc.
A PC installed with a Modbus driver and SCADA software, a Modbus-compatible PLC, etc.
Personal computer etc. with SCADA software installed to support PR201 original communication protocol
1-1

1.2 Ethernet Communication Specifications

Protocols available for Ethernet communication interfaces include the Modbus/TCP communication protocol.
Table 1.2 Ethernet Communication Specifications
Item Details
Communication Hardware Compliant Standard Access Control Protocol Specification Baud Rate Maximum Segment Length Maximum Connecting
Configuration Communication System Data Format Maximum Number of
Connections *1: Distance between the hub and module.
*2: The number of hubs connectable in cascade configuration.
10BASE-T/100BASE-TX Ethernet IEEE802.3 CSMA/CD Modbus communication (Port No.: 502) 10 Mbps/100 Mbps 100 m *1 Cascade max. 4 levels (for 10BASE-T)
max. 2 levels (for 100BASE-TX) *2 TCP/IP Binary 1
Connected Device
Ethernet-equipped PC etc.
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2. Setup

This chapter describes how to set up the PR300, which is equipped with RS-485 communication as a standard feature.
When using an Ethernet-equipped model, either RS-485 or Ethernet can be selected by parameter setting for communications.
For details of use of RS-485 communication, see subsection 2.1.1 Procedure for RS-485 Communication.
For details of use of the Ethernet communication, see subsection 2.1.2 Procedure for Ethernet Communication.
For details of use of the Ethernet-serial gateway function, see subsection 2.1.3 Procedure for Ethernet-Serial Gateway Function.

2.1 Setup Procedure

Set up the communication functions on the PR300 as follows:
2-1
WARNING
To avoid an electric shock, be sure to turn off the power supply source to the equipment involved before you start wiring.
Note: Create communication programs referring to the user’s manual for communications of each higher-level device.
Higher-level devices : PCs, PLCs (sequencers), and others.
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2.1.1 Procedure for RS-485 Communication

(Example)
Higher-level device
Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
2-2
Station number 01
(arbitrary)
Communication parameters setting for PR300
1
Set up the communication function using the front panel keys.
Connect a higher-level device with PR300
2
Create communication programs for the
3
higher-level device to perform communication
Station number 02
(arbitrary)
Subsection 2.2.1 Conditions for RS-485 Communication
Subsection 2.3.1 Wiring for RS-485 Communication
Chapter 3 Procedures for Setting PR300 Functions
For communication protocol, see Chapter 4 PC Link Communication Protocol Chapter 5
Modbus/RTU and ASCII Communication Protocols
Chapter 8 PR201 Original Communication Protocol
For data storage location, see Chapter 7 Functions and Usage of D Registers
See
See
See
Station number 10
(arbitrary)
Station number 20
(arbitrary)
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2.1.2 Procedure for Ethernet Communication

(Example)
2-3
Higher-level device IP address [192.168.1.1]
HUB
LAN connection
Station number 01 (fixed) IP address [192.168.1.2] (arbitrary)
Communication parameters setting for PR300
1
Set up the communication function using
(arbitrary)
Ethernet
Station number 01 (fixed) IP address [192.168.1.3] (arbitrary)
the front panel keys.
See
Subsection 2.2.2 Conditions for Ethernet Communication
Connect a higher-level device with PR300
2
See
Subsection 2.3.2 Wiring for Ethernet Communication
Maximum distance between hub and module: 100 m Maximum number of hubs connectable in cascade configuration: 4 levels for 10BASE-T 2 levels for 100BASE-TX
Station number 01 (fixed) IP address [192.168.1.4] (arbitrary)
Station number 01 (fixed) IP address [192.168.1.5] (arbitrary)
Create communication programs for the
3
higher-level device to perform communication
See
Chapter 3 Procedures for Setting PR300 Functions
For communication protocol, see Chapter 6
Modbus/TCP Communication Protocol
For data storage location, see Chapter 7 Functions and Usage of D Registers
Note: It is recommended to use the Ethernet network as a dedicated one for the
PR300.
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2.1.3 Procedure for Ethernet-Serial Gateway Function

(Example)
Higher-level device IP address [192.168.1.1] (arbitrary)
Ethernet
2-4
PR300
communication function)
(with Ethernet
Communication parameters setting for PR300
1
Set up the communication function using the front panel keys.
Connect a higher-level device with PR300
2
RS-485
Station number 02
(arbitrary)
Subsection 2.2.2 Conditions for Ethernet Communication Subsection 2.2.3
Subsection 2.3.2 Wiring for Ethernet Communication
Station number 01 (fixed) IP address [192.168.1.2] (arbitrary)
Station number 03
(arbitrary)
See
Conditions for Ethernet-Serial Gateway Function
See
Station number 20
(arbitrary)
Connect a lower-level device with PR300
3
See
Subsection 2.3.3 Wiring for RS-485 Communication for Ethernet-Serial Gateway Function
Create communication programs for the
4
higher-level device to perform communication
Note: It is recommended to use the Ethernet network as a dedicated one for the PR300.
See
Chapter 3 Procedures for Setting PR300 Functions
For communication protocol, see Chapter 6
Modbus/TCP Communication Protocol
For data storage location, see Chapter 7 Functions and Usage of D Registers
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VJET Ethernet/RS-485 converter as an Ethernet-serial gateway function
(Example)
Higher-level device IP address [192.168.1.1] (arbitrary)
Ethernet
2-5
Ethernet/RS-485 converter
VJET*
RS-485
Station number 02 (arbitrary) Station number 03 (arbitrary)
* The VJET is Yokogawas converter. For details of use of the VJET, refer to its users manual.
Note: It is recommended to use the Ethernet network as a dedicated one for the PR300.
The communication conditions of any slave PR300 must conform to those of the VJET at a higher level.
Station number 01 (fixed) IP address [192.168.1.2] (arbitrary)
Station number 20 (arbitrary)
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2.2 Setting Communication Conditions

This section describes the setting parameters for using the communication func­tions, and the setting ranges. For details of setting method, refer to the PR300 Power and Energy Meter Users Manual (electronic manual).

2.2.1 Conditions for RS-485 Communication

This subsection describes the setting parameters for using the RS-485 communication function, and the setting ranges.
Table 2.1 Parameters to be Set for Communication Functions
Parameter Name
Menu
Parameter Symbol
Setting Range
2-6
Initial
Value
Station number
Protocol
Baud rate
3
Parity*
Stop bit*
3
(RS-485
communication)
(ST-NO)
(COMM)
(B-RT)
(PRI)
(STP)
01 to 99 (01 to 31 recommended)
PC link without checksum
PC link with checksum
Modbus/ASCII
Modbus/RTU
Modbus/TCP*
PR201 original
1
(PCLK1)
(PCLK2)
(M ASC)
(M RTU)
(M TCP)
(PR201)
2400 bps 9600 bps 19200 bps
None
Even
Odd
(NONE)
(EVEN)
(ODD)
1
2
01
PCLK2
9600
NONE
1
Data length*2 *
*1: Modbus/TCP can be selected for the PR300 with Ethernet communication function only. *2: When Modbus /RTU is selected for the protocol, select 8 for the data length. If 7 is selected for the data length,
communication is not possible.
*3: When PR201 original is selected for the protocol, select NONE for the parity, 1 for the stop bit and 8 for the data length.
3
(DLN)
7
8
8
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Protocol (COMM)
Set the communication protocol identical to that of the higher-level device to be connected.
Station number (ST-NO)
Set the station number of the PR300 itself. A station number of 01 to 99 may be assigned in any order. However, the maximum number of PR300 to be connected to a single com­munication port is 31.
When connecting two or more PR300 to a single communication port, set a different station number to each.
Example of connecting a higher-level device with four PR300 having station numbers 01, 05, 10, and 20
(Example)
Higher-level device
2-7
Maximum communication distance: 1200 m Maximum number of slave sations to be connected: 31
Station number 01
(arbitrary)
Station number 05
(arbitrary)
Station number 10
(arbitrary)
Station number 20
(arbitrary)
Baud rate (B-RT)
Set the baud rate identical to that of the higher-level device to be connected. (Otherwise, proper communication cannot be achieved.)
Parity (PRI)
Set the handling of parity to be carried out when data is sent or received. Set the parity bit state identical to that of the higher-level device to be connected.
* When PR201 original is selected for the protocol, select NONE for the parity.
Stop bit (STP)
Set the stop bit identical to that of the higher-level device to be connected.
* When PR201 original is selected for the protocol, select 1 for the stop bit.
Data length (DLN)
Set the same data length as for the upper device that is to be connected.
* When Modbus/RTU is selected for the protocol, select 8 for the data length. * When PR201 original is selected for the protocol, select 8 for the data length.
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2.2.2 Conditions for Ethernet Communication

This subsection describes the setting parameters for using the Ethernet communication function, and the setting ranges.
Table 2.2 Parameters to be Set for Communication Functions
Parameter Name
Menu
Parameter Symbol
Setting Range
2-8
Initial
Value
Protocol
IP address-1
IP address-2
IP address-3
IP address-4
Subnet mask-1
Subnet mask-2
(RS-485
Communication)
(COMM)
(IP-1)
(IP-2)
(IP-3)
(IP-4)
(SM-1)
(SM-2)
PC link without checksum
PC link with checksum
Modbus/ASCII
Modbus/RTU
Modbus/TCP*
1
PR201 original
0 to 255
0 to 255
0 to 255
0 to 255
0 to 255
0 to 255
(PCLK1)
(PCLK2)
(M ASC)
(M RTU)
(M TCP)
(PR201)
PCLK2
192
168
1
1
255
255
Subnet mask-3
(SM-3)
(Ethernet
Subnet mask-4
Communication)
2
*
(SM-4)
Default gateway-1
(DG-1)
Default gateway-2
(DG-2)
Default gateway-3
(DG-3)
Default gateway-4
(DG-4)
Port number
(PORT)
Ethernet setting switch
(E-SW)
*1: Modbus/TCP can be selected for the PR300 with Ethernet communication function only. *2: Ethernet communication menu is displayed when Modbus/TCP is selected for the protocol.
0 to 255
0 to 255
0 to 255
0 to 255
0 to 255
0 to 255
502, 1024 to 65535
OFF, ON
255
0
0
0
0
0
502
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Protocol (COMM)
Set the protocol to Modbus/TCP.
IP address-1 to 4 (IP-n) [n: integers from 1 to 4]
Set the IP address for the PR300 by the following format.
2-9
0 to 255
IP address IP-1
0 to 255
IP-2
0 to 255
IP-3
0 to 255
IP-4
Subnet mask-1 to 4 (SM-n) [n: integers from 1 to 4]
Set the subnet mask for the PR300 by the following format.
0 to 255
Subnet Mask SM-1
0 to 255
SM-2
0 to 255
SM-3
0 to 255
SM-4
Default gateway-1 to 4 (DG-n) [n: integers from 1 to 4]
Set the default gateway for the PR300 by the following format.
0 to 255
Default Gateway DG-1
0 to 255
DG-2
0 to 255
DG-3
0 to 255
DG-4
NOTE
Before performing setup of IP address, subnet mask, and default gateway, consult the administrator for the network to which the PR300 is to be connected.
Port number (PORT)
Set the port number for the PR300.
NOTE
To activate the settings of IP address, subnet mask, default gateway, and port number, set the Ethernet setting switch to ON after setting them.
Ethernet setting swtich (E-SW)
This switch activates the Ethernet communication parameters settings. Setting this param­eter to ON activates the settings of IP address, subnet mask, default gateway, and port number.
This parameter automatically reverts to OFF in about 20 seconds after being set to ON.
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2.2.3 Conditions for Ethernet-Serial Gateway Function

The Ethernet-serial gateway function is a function that reads/writes data from/to other devices equipped with RS-485 serial communication function using the Modbus/TCP protocol via the PR300.
With this function, the higher-level device can access the devices connected to the RS-485 serial communication line in the same way as to access the devices connected to Ethernet.
(Example)
Higher-level device
2-10
PR300
communication function)
Device with RS-485 serial communication function
Power Monitor of POWERCERT series Digital indicating controller of GREEN series Signal conditioner of JUXTA series
(with Ethernet
Ethernet
RS-485
Station number 02
(arbitrary)
10BASE-T, 100BASE-TX
Station number 01 (fixed)
Station number 03
(arbitrary)
Station number 04
(arbitrary)
The PR300 operates as a gateway that changes the Modbus/TCP protocol received via network to the Modbus/RTU protocol for the serial devices connected to the RS-485 communication interface. Therefore, the devices supporting the Modbus/RTU protocol are required for the devices to be connected.
NOTE
If the Ethernet-serial gateway function is used, set a station number other than 01 for the RS-485 communication devices which are slaves of the PR300 connected to Ethernet.
If the Ethernet communication function is used, the RS-485 communication interface is used specifically for the Ethernet-serial gateway function. Therefore, it is not pos­sible for a higher-level device such as a PC to access the PR300 via the RS-485 communication interface.
IM 77C01E01-10E
<Toc> <Ind> <2. Setup>
Setting for PR300 to perform the Ethernet-serial gateway function
To use the Ethernet-serial gateway function, set the parameters of subsection 2.2.2, Con­ditions for Ethernet Communication and set a parity (PRI) in Table 2.3.
When the protocol is set to Modbus/TCP, the parameters of RS-485 other than the parity are fixed and unchangeable.
Table 2.3 Parameters of PR300 to Perform the Ethernet-Serial Gateway Function
Parameter Name
Menu Setting Range
Parameter Symbol
2-11
Initial Value
Station number
Baud rate
Parity
Stop bit
Data length
(RS-485
communication)
(ST-NO)
(B-RT)
(PRI)
(STP)
(DLN)
01 (fixed)
9600 bps (fixed)
None Even
Odd
1 (fixed)
8 (fixed)
NONE EVEN ODD
Slave PR300
The station number of any slave PR300 (device for RS-485 communication) must be a different number other than 01.
The communication conditions for any slave PR300 (device for RS-485 communication) other than the station number must conform to those in Table 2.3.
Table 2.4 Parameters of Slave PR300
Parameter Name
Station number
Baud rate
Parity
Stop bit
Menu Setting Range
(RS-485
communication)
Parameter Symbol
(ST-NO)
(B-RT)
(PRI)
(STP)
02 to 99
2400 bps 9600 bps 19200 bps
None Even Odd
1
2
NONE EVEN ODD
01
9600
NONE
1
8
Initial
Value
01
9600
NONE
1
Data length
(DLN)
8
8
When using the VJET Ethernet/RS-485 converter as an Ethernet-serial gateway function, the communication conditions of any slave PR300 must conform to those of the VJET at a higher level. The initial value of the VJET parity is EVEN.
IM 77C01E01-10E
7
<Toc> <Ind> <2. Setup>

2.3 Wiring for Communication

Connect a higher-level device with the PR300 for using the communication func­tions. The wiring procedures and precautionary notes are as follows.

2.3.1 Wiring for RS-485 Communication

For a common PC, the RS-485 interface is not directly connectable. Use a ML2 RS232C/ RS485 converter for wiring.
WARNING
To avoid an electric shock, be sure to turn off the power supply source to the equipment involved before you start wiring.
Use crimp-on terminals at cable ends. Before you start wiring, read the users manual of each device.
PR300 (with RS-485 communication function)
17
A
18
B
19
PC
(RS232C/RS485 converter)
Terminator
120 1/4W
3
4
A
B
PR300 (with RS-485 communication function)
18
19
2-12
Terminator (built-in)
120 1/4W
Wthen terminating on wiring, short-circuit terminals 17 and 18 .
SG
RS-232C straight cable
SG
5
6
JIS Class D (3) grounding (grounding resistance of 100 or less)
20
Communication cableCommunication cable
JIS Class D (3) grounding (grounding resistance of 100 or less)
Note: Use UL Listed RS-232C/RS-485 converter if the converter has AC/DC power supply input; this is
optional for converters supplied by a Limited Power Source with input voltages less than 30 V AC or 60 V DC and which are separated from mains by double or reinforced insulation.
Communication cable: Shielded twisted pair cable (AWG24-eqivalent size) Recommended terminals: See the PR300 Power and Energy Meter Users Manual (electronic manual).
20
IM 77C01E01-10E
<Toc> <Ind> <2. Setup>

2.3.2 Wiring for Ethernet Communication

To use the Ethernet communication function, connect a higher-level device with the PR300 with Ethernet communication function using 10BASE-T/100BASE-TX. 10BASE-T/ 100BASE-TX are Ethernet connection methods using twisted pair cables. The transmission rates are 10 Mbps/100 Mbps. In 10BASE-T/100BASE-TX networks, higher-level devices such as a PC are connected in a star pattern through a hub.
WARNING
To avoid an electric shock, be sure to turn off the power supply source to the equipment involved before you start wiring.
Use hubs and twisted pair cables that conforms to the Ethernet specifications. The maxi­mum number of hubs connectable in cascade configuration is 4 for 10ABSE-T and 2 for 100BASE-TX. The maximum allowable length of twisted pair cables is 100 meters.
Read the users manual of each device carefully before wiring.
* Devices that can be connected to Ethernet
PC
2-13
PR300 with Ethernet communication function
HUB
Data transmission
and reception
Ethernet
Ethernet Port of PR300
The PR300 can detect 10BASE-T or 100BASE-TX automatically. The LEDs of Ethernet port show its status.
Link LED (upper side) Color Off Amber Green Activity LED (lower side) Color Off Amber Green
Meaning No Link 10 Mbps 100 Mbps
Meaning No Activity Half-duplex Full-duplex
IM 77C01E01-10E
<Toc> <Ind> <2. Setup>

2.3.3 Wiring for RS-485 Communication for Ethernet-Serial Gateway Function

To use the Ethernet-serial gateway function, connect other RS-485 serial communication device to the RS-485 communication terminals .
WARNING
To avoid an electric shock, be sure to turn off the power supply source to the equipment involved before you start wiring.
The figure below shows the example of wiring connection for the PR300 with Ethernet communication function. If other devices are used for connection, the names of communi­cation terminals and others may be different from those mentioned in the figure.
Read the users manual of each device carefully before wiring.
PC
2-14
(with Ethernet
communication function)
Terminator (built-in)
120 1/4W
Wthen terminating on wiring, short-circuit terminals 17 and 18 .
Ethernet
PR300
PR300
(with RS-485
17 17
A
18
B
19
SG
Communication
cable
communication function)
18
19
2020
JIS Class D (3) grounding
(grounding resistance
of 100 or less)
Communication
cable
PR300
(with RS-485
communication function)
A
B
SG
Terminator (built-in)
18
19
20
120 1/4W
Wthen terminating on wiring, short-circuit terminals 17 and 18 .
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>
3-1

3. Procedures for Setting PR300 Functions

To set the functions of the PR300, use the protocols described in Chapter 4, PC Link Communication Protocol, Chapter 5, Modobus/RTU and ASCII Communica­tion Protocols, or Chapter 6, Modbus/TCP Communication Protocol according to the instructions in this chapter.
For details of each function, refer to the PR300 Power and Energy Meter User’s Manual (electronic manual).
For how to read the tables in this chapter, refer to Chapter 7, “Functions and Usage of D Registers.
The PR300 offers registers for floating-point data. To perform settings via communi­cation from higher-level device, floating-point data is displayed by IEEE754 (single precision).
NOTE
The PR300 has data (D register) the unit of which is two words. When 2-word data need to be written or read, writing or reading operations must be performed for the 2­word data at the same time.
Even if data written to the D register is out of the effective range, a normal response is returned. The part of the written data within the effective range becomes effective on the PR300 when the equivalent setting change status is written for that data.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.1 Basic Setting

3.1.1 Setting of VT Ratio

[Procedure]
(1) Write a VT ratio to the two D registers in the table below. The data type is 4-byte
floating point.
(2) After writing that value, write 1 to the setup change status register, D0207.
3-2
D Register
D0201 D0202
D0207
Initial value of VT ratio: 1 (4-byte floating-point data: 3F800000)
Reference No.
40201 40202
40207
H No.
00C8 00C9
00CE
VT ratio (float, lower 2 bytes) VT ratio (float, upper 2 bytes) Setup change status
(D0201 to D0206 are validated)
Description
Effective Range
1 to 6000
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the VT ratio to 10: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10 is converted into a 4-byte floating-point value, the value is 4120 0000.
[Command] [STX] 01010WRW03D0201, 0000, D0202, 4120, D0207, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
When changing the VT ratio, the integrated values of active energy, reactive energy, apparent energy, optional active energy, and regenerative energy will return to 0. The values of the demand alarm point and the scaling of analog output will also be initialized.
Set the VT and CT ratios so that [secondary rated power] × [VT ratio] × [CT ratio] is smaller than 10 GW. When this value is 10 GW or greater, writing to D registers will be invalid (no error is output).
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.1.2 Setting of CT Ratio

[Procedure]
(1) Write a CT ratio to the two D registers in the table below. The data type is 4-byte
floating point.
(2) After writing that value, write 1 to the setup change status register, D0207.
3-3
D Register
D0203 D0204
D0207
Initial value of CT ratio: 1 (4-byte floating-point data: 3F800000)
Reference No.
40203 40204
40207
H No.
00CA 00CB
00CE
CT ratio (float, lower 2 bytes) CT ratio (float, upper 2 bytes) Setup change status
(D0201 to D0206 are validated)
Description
Effective Range
0.05 to 32000
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the CT ratio to 10.0: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10.0 is converted into a 4-byte floating-point value, the value is 4120 0000.
[Command] [STX] 01010WRW03D0203, 0000, D0204, 4120, D0207, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
When changing the CT ratio, the integrated values of active energy, reactive energy, apparent energy, optional active energy, and regenerative energy will return to “0. The values of the demand alarm point and the scaling of analog output will also be initialized.
Set the VT and CT ratios so that [secondary rated power] × [VT ratio] × [CT ratio] is smaller than 10 GW. When this value is 10 GW or greater, writing to D registers will be invalid (no error is output).
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.1.3 Setting of Integrated Low-cut Power

[Procedure]
(1) Write an integrated low-cut power value to the two D registers in the table below. The
data type is 4-byte floating point.
(2) After writing that value, write 1 to the setup change status register, D0207.
3-4
D Register
D0205
D0206
D0207
Initial value of integrated low-cut power: 0.05% (4-byte floating-point data: 3D4CCCCD)
Reference No.
40205
40206
40207
H No.
00CC
00CD
00CE
Description
Integrated low-cut power (float, lower 2 bytes)
Integrated low-cut power (float, upper 2 bytes)
Setup change status (D0201 to D0206 are validated)
Effective Range
0.05 to 20.00 Unit: %
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the integrated low-cut power value to 10.0%: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10.0 is converted into a 4-byte floating-point value, the value is 4120 0000.
[Command] [STX] 01010WRW03D0205, 0000, D0206, 4120, D0207, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.2 Setting Pulse Output

3.2.1 Selection of Measurement Item for Pulse Output

[Procedure]
(1) Write a measurement item for pulse output value to the D register in the table below.
The data type is integer.
(2) After writing that value, write 1 to the pulse output writing status register, D0211.
3-5
D Register
D0208
D0211
Initial value of measurement item for pulse output: 0 (active energy)
Reference No.
40208
40211
H No.
00CF
00D2
Description
Measurement item for pulse output
Pulse output writing status (D0208, D0209, and D0210 are validated)
Effective Range
0: Active energy 1: Regenerative energy 2: LEAD reactive energy 3: LAG reactive energy 4: Apparent energy
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the measurement item for pulse output to 1 (LEAD reactive energy): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW02D0208, 0001, D0211, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
A measurement item for pulse output value can be set for the PR300 with pulse output.
When the PR300 is the three-phase four-wire system (2.5 element), the following measurement items can be measured only when the current is in a state of equilib­rium: 2: LEAD reactive energy, “3: LAG reactive energy” and “4: Apparent energy.”
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.2.2 Pulse Unit

[Procedure]
(1) Write a pulse unit value to the D register in the table below. The data type is integer. (2) After writing that value, write 1 to the pulse output writing status register, D0211.
3-6
D Register
D0209
D0211
Initial value of pulse unit: 10 (1000 Wh/pulse)
Reference No.
40209
40211
H No.
00D0
00D2
Description
Pulse unit
Pulse output writing status (D0208, D0209, and D0210 are validated)
Effective Range
1 to 50,000 Unit: 100 Wh/pulse
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the pulse unit to 100 Wh/pulse, write “0001.” For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0209,0001,D0211,0001[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
A pulse unit value can be set for the PR300 with pulse output.
To set the pulse unit value via communication, set it to 1/100 the value of the displayed
(true) value (e.g., set it to 5 when setting the pulse unit value to 500 Wh/pulse).
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.2.3 ON Pulse Width

(1) Write an ON pulse width value to the D register in the table below. The data type is
integer.
(2) After writing that value, write 1 to the pulse output writing status register, D0211.
NOTE
When the value to be set for the ON pulse width is greater than the value calculated by the following equation, the value cannot be set:
3-7
ON pulse width (ms)
D Register
D0210
D0211
Initial value of ON pulse width: 5 (50 ms)
Reference No.
40210
40211
Secondary rated power [W] VT ratio CT ratio 1.2  2
00D1
00D2
H No.
Pulse unit [Wh/pls] 60 60  1000
Description
ON pulse width
Pulse output writing status (D0208, D0209, and D0210 are validated)
Effective Range
1 to 127 Unit: 10 ms
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the ON pulse width to 100 ms, write “000A.” For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW02D0210, 000A, D0211, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
An ON pulse width value can be set for the PR300 with pulse output.
To set the ON pulse width value via communication, set it to 1/10 the value of the
displayed (true) value (e.g., set it to 5 when setting the ON pulse width value to 50 ms).
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.3 Setting Analog Output

3.3.1 Selection of Measurement Item for Analog Output

[Procedure]
(1) Write a measurement item for analog output value to the D register in the table below.
The data type is integer.
(2) After writing that value, write 1 to the analog output writing status register, D0217.
3-8
D Register
D0212
D0217
Initial value of measurement item for analog output: 0 (active power)
Reference No.
40212
40217
H No.
00D3
00D8
Description
Measurement item for analog output
Analog output writing status (D0212 to D0216 are validated)
Effective Range
0: Active power 1: Reactive power 2: Apparent power 3: Voltage-1 4: Voltage-2 5: Voltage-3 6: Current-1 7: Current-2 8: Current-3 9: Power factor 10: Frequency
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the measurement item for analog output to 3 (voltage-1): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW02D0212, 0003, D0217, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
A measurement item for analog output value can be set for the PR300 with analog output.
Different types of the PR300 can measure different items, and so the values that can be set to the D register differ depending on the PR300 type. If a value that cannot be written to the D register is written, it will be invalid. The table below shows the values that cannot be set for four types of the PR300:
Phase and Wire System Single-phase two-wire Single-phase three-wire Three-phase three-wire Three-phase four-wire (2.5 element)
4: Voltage-2, 5: Voltage-3, 7: Current-2, and 8: Current-3 5: Voltage-3 and 8: Current-3 4: Voltage-2 and 7: Current-2 4: Voltage-2 and 7: Current-2
When the PR300 is the three-phase four-wire system (2.5 element), the following measurement items can be measured only when the current is in a state of equilib­rium: 1: Reactive power, “2: Apparent power”, “6: Current-1”, “8: Current-3” and “9: Power factor.
Values that cannot be Set
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.3.2 Upper/Lower Limits of Scaling

[Procedure]
(1) Write upper/lower limits of scaling value to the four D registers in the table below. The
data type is 4-byte floating point.
(2) After writing that value, write 1 to the analog output writing status register, D0217.
3-9
D Register
D0213
D0214
D0215
D0216
D0217
Initial value of lower limit of scaling: 50% Initial value of upper limit of scaling: 100%
Reference No.
40213
40214 00D5
40215 00D6
40216 00D7
40217
H No.
00D4
00D8
Description
Lower limit of scaling (float, lower 2 bytes)
Lower limit of scaling (float, upper 2 bytes)
Upper limit of scaling (float, lower 2 bytes)
Upper limit of scaling (float, upper 2 bytes)
Analog output writing status (D0212 to D0216 are validated)
Effective Range
0.0 to 50.0 Unit: %
50.0 to 100.0 Unit: %
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the lower limit of scaling to 10.0%: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10.0 is converted into a 4-byte floating point value, the value is 4120 0000.
[Command] [STX] 01010WRW03D0213, 0000, D0214, 4120, D0217,0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
An upper/lower limit of scaling value can be set for the PR300 with analog output.
Set an upper/lower limit of scaling so that [upper limit of scaling] [lower limit of
scaling] is 50% or greater. If it is smaller than 50%, writing to the D register will be invalid.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4 Demand Setting

3.4.1 Demand Power/Current

[Procedure]
(1) Write a demand power/current value to the D register in the table below. The data type
is integer.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-10
D Register
D0218
D0226
Initial value of demand power/current: 0 (active power)
Reference No.
40218
40226
H No.
00D9
00E1
Description
Demand power/current
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
0: Active power 1: Current
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the demand power/current to 1 (current): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW02D0218, 0001, D0226, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
A demand power/current value can be set for the PR300 with demand measuring function.
When the PR300 is the three-phase four-wire system (2.5 element), 1: Current can be measured only when the current is in a state of equilibrium.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4.2 Demand Period

[Procedure]
(1) Write a demand period value to the D register in the table below. The data type is
integer.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-11
D Register
D0219
D0226
Initial value of demand period: 30 minutes
Reference No.
40219
40226
00DA
00E1
H No.
Description
Demand period
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
1 to 60 (Demand alarm mask time to 60) Unit: minute
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the demand period to 20 minutes: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW02D0219, 0014, D0226, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
NOTE
A demand period value can be set for the PR300 with demand measuring function.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4.3 Demand Alarm Mask Time

[Procedure]
(1) Write a demand alarm mask time value to the D register in the table below. The data
type is integer.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-12
D Register
D0220
D0226
Initial value of demand alarm mask time: 1 minute
Reference No.
40220
40226
H No.
00DB
00E1
Description
Demand alarm mask time
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
1 to 59 (1 to demand period)
Unit: minute
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the demand alarm mask time to 20 minutes: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0220,0014,D0226,0001[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
A demand alarm mask time value can be set for the PR300 with demand measuring
function.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4.4 Demand Power Alarm Point

[Procedure]
(1) Write a demand power alarm point value to the two D registers in the table below. The
data type is 4-byte floating point.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-13
D Register
D0221
D0222
D0226
Initial value of demand power alarm point: 100 kW
Reference No.
40221
40222 00DD
40226
H No.
00DC
00E1
Description
Demand power alarm point (float, lower 2 bytes)
Demand power alarm point (float, upper 2 bytes)
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
1 to 1000 Unit: kW
If other than 1: Invalid If 1: Writing is executed
[Example] To set the demand power alarm point to 10.0 kW: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10.0 is converted into a 4-byte floating point value, the value is 4120 0000.
[Command] [STX]01010WRW03D0221,0000,D0222,4120,D0226,0001[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
A demand power alarm point value can be set for the PR300 with demand measuring
function.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4.5 Demand Current Alarm Point

[Procedure]
(1) Write a demand current alarm point value to the two D registers in the table below.
The data type is 4-byte floating point.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-14
D Register
D0223
D0224
D0226
Initial value of demand current alarm point: 100 A
Reference No.
40223
40224 00DF
40226
H No.
00DE
00E1
Description
Demand current alarm point (float, lower 2 bytes)
Demand current alarm point (float, upper 2 bytes)
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
1 to 1000 Unit: A
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the demand current alarm point to 10.0 A: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10.0 is converted into a 4-byte floating point value, the value is 4120 0000.
[Command] [STX]01010WRW03D0223,0000,D0224,4120,D0226,0001[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
A demand current alarm point value can be set for the PR300 with demand measuring
function.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.4.6 Demand Alarm Release Function

[Procedure]
(1) Write a demand alarm release function value to the D register in the table below. The
data type is integer.
(2) After writing that value, write 1 to the demand measurement writing status register,
D0226.
3-15
D Register
D0225
D0226
Initial value of demand alarm release function: 0 (automatic release)
Reference No.
40225
40226
H No.
00E0
00E1
Description
Demand alarm release function
Demand measurement writing status (D0218 to D0225 are validated)
Effective Range
0: Automatic
1: Manual release
If other than 1: Invalid If 1: Writing is executed
release
[Example]
To set the demand alarm release function to 0 (automatic release): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0225,0000,D0226,0001[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
A demand alarm release function value can be set for the PR300 with demand mea­suring function.
When the demand alarm release function is used by digital input, releasing via com­munication is not possible.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5 Communication Setting

3.5.1 Protocol

[Procedure]
(1) Write a protocol value to the D register in the table below. The data type is integer. (2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-16
D Register
D0271
D0277
Initial value of protocol: 1 (PC link with checksum) *1: Modbus/TCP can be selected for the PR300 with Ethernet communication function only.
Reference No.
40271
40277
H No.
010E
0114
Description
Protocol
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
0: PC link (without checksum) 1: PC link (with checksum) 2: Modbus/ASCII 3: Modbus/RTU 4: Modbus/TCP * 5: PR201 original
If other than 1: Invalid If 1: Writing is executed
1
NOTE
When Modbus/TCP is selected for the protocol, the baud rate, the stop bit, the data length and the station number are fixed and unchangeable.
When PR201 original is selected, the baud rate, the parity, the stop bit and the data length cannot be set via communication.
[Example]
To set the protocol to 4 (Modbus/TCP): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0271,0004,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.2 Baud Rate

[Procedure]
(1) Write a baud rate value to the D register in the table below. The data type is integer. (2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-17
D Register
D0272
D0277
Initial value of baud rate: 1 (9600 bps)
Reference No.
40272
40277
H No.
010F
0114
Description
Baud rate
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
0: 2400 bps 1: 9600 bps 2: 19200 bps
If other than 1: Invalid If 1: Writing is executed
NOTE
When Modbus/TCP is selected for the protocol, the baud rate is fixed and unchangeable at 9600 bps.
[Example]
To set the baud rate to 2 (19200 bps): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0272,0002,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.3 Parity

[Procedure]
(1) To set the parity, write data to the D register in the table below. The data type is integer. (2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-18
D Register
D0273
D0277
Initial value of parity: 0 (NONE)
Reference No.
40273
40277
H No.
0110
0114
Description
Parity
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
0: NONE 1: EVEN 2: ODD
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the parity to 1 (EVEN): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0273,0001,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.4 Stop Bit

[Procedure]
(1) To set the stop bit, write data to the D register in the table below. The data type is
integer.
(2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-19
D Register
D0274
D0277
Initial value of stop bit: 1 (1 bit)
Reference No.
40274
40277
H No.
0111
0114
Description
Stop bit
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
1: 1 bit 2: 2 bits
If other than 1: Invalid If 1: Writing is executed
NOTE
When Modbus/TCP is selected for the protocol, the stop bit is fixed and unchangeable at 1 bit.
[Example]
To set the stop bit to 2 (2 bits): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0274,0002,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.5 Data Length

[Procedure]
(1) To set the data length, write data to the D register in the table below. The data type is
integer.
(2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-20
D Register
D0275
D0277
Initial value of data length: 0 (8 bits)
Reference No.
40275
40277
H No.
0112
0114
Description
Data length
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
0: 8 bits 1: 7 bits
If other than 1: Invalid If 1: Writing is executed
NOTE
When Modbus/TCP is selected for the protocol, the data length is fixed and unchangeable at 8 bits.
[Example]
To set the data length to 1 (7 bits): For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0275,0001,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.6 Station Number

[Procedure]
(1) To set the station number, write data to the D register in the table below. The data type
is integer.
(2) After writing that value, write 1 to the RS-485 writing status register, D0277.
3-21
D Register
D0276
D0277
Initial value of station number: 01
Reference No.
40276
40277
H No.
0113
0114
Description
Station number
RS-485 writing status (D0271 to D0276 are validated)
Effective Range
01 to 99
If other than 1: Invalid If 1: Writing is executed
NOTE
When Modbus/TCP is selected for the protocol, the station number is fixed and unchange­able at 01.
[Example]
To set the station number to 02: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0276,0002,D0277,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.7 IP Address (for Ethernet communication)

[Procedure]
(1) To set the IP address, write data to the four D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the Ethernet writing status register, D0294.
3-22
D Register
D0281 D0282 D0283 D0284
D0294
Initial value of IP address: 192.168.1.1
Reference No.
40281 40282 40283 40284
40294
H No.
0118 0119 011A 011B
0125
0 to 255
IP address IP-1
Description
IP address-1 (IP-1) IP address-2 (IP-2) IP address-3 (IP-3) IP address-4 (IP-4)
Ethernet writing status (D0281 to D0293 are validated)
0 to 255
IP-2
0 to 255
IP-3
Effective Range
0 to 255 0 to 255 0 to 255 0 to 255
If other than 1: Invalid If 1: Writing is executed
0 to 255
IP-4
NOTE
An IP address value can be set for the PR300 with Ethernet communication function.
IP address settings are only effective when the protocol is set to Modbus/TCP.
[Example]
To set the IP address to 192.168.1.3: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW05D0281,00C0,D0282,00A8,D0283,0001,D0284,0003,D0294,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.8 Subnet Mask (for Ethernet communication)

[Procedure]
(1) To set the subnet mask, write data to the four D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the Ethernet writing status register, D0294.
3-23
D Register
D0285 D0286 D0287 D0288
D0294
Initial value of subnet mask: 255.255.255.0
Reference No.
40285 40286 40287 40288
40294
Subnet Mask
H No.
011C 011D 011E 011F
0125
Description
Subnet mask-1 (SM-1) Subnet mask-2 (SM-2) Subnet mask-3 (SM-3) Subnet mask-4 (SM-4)
Ethernet writing status (D0281 to D0293 are validated)
0 to 255
SM-1
0 to 255
SM-2
0 to 255
SM-3
Effective Range
0 to 255 0 to 255 0 to 255 0 to 255
If other than 1: Invalid If 1: Writing is executed
0 to 255
SM-4
NOTE
A subnet mask value can be set for the PR300 with Ethernet communication function.
Subnet mask settings are only effective when the protocol is set to Modbus/TCP.
[Example]
To set the subnet mask to 255. 255. 255. 0: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW05D0285,00FF,D0286,00FF,D0287,00FF,D0288,0000,D0294,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.9 Default Gateway (for Ethernet communication)

[Procedure]
(1) To set the default gateway, write data to the four D registers in the table below. The
data type is integer.
(2) After writing that value, write 1 to the Ethernet writing status register, D0294.
3-24
D Register
D0289 D0290 D0291 D0292
D0294
Initial value of default gateway: 0.0.0.0
Reference No.
40289 40290 40291 40292
40294
H No.
0120 0121 0122 0123
0125
Default Gateway
Description
Default gateway-1 (DG-1) Default gateway-2 (DG-2) Default gateway-3 (DG-3) Default gateway-4 (DG-4)
Ethernet writing status (D0281 to D0293 are validated)
0 to 255
DG-1
0 to 255
DG-2
Effective Range
0 to 255 0 to 255 0 to 255 0 to 255
If other than 1: Invalid If 1: Writing is executed
0 to 255
DG-3
0 to 255
DG-4
NOTE
A default gateway value can be set for the PR300 with Ethernet communication function.
Default gateway settings are only effective when the protocol is set to Modbus/TCP.
[Example]
To set the default gateway to 0. 0. 0. 0: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW05D0289,0000,D0290,0000,D0291,0000,D0292,0000,D0294,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.5.10 Port Number (for Ethernet communication)

[Procedure]
(1) To set the port number, write data to the D register in the table below. The data type is
integer.
(2) After writing that value, write 1 to the Ethernet writing status register, D0294.
3-25
D Register
D0293
D0294
Initial value of port number: 502
Reference No.
40293
40294
H No.
0124
0125
Description
Port number
Ethernet writing status (D0281 to D0293 are validated)
Effective Range
502, 1024 to 65535
If other than 1: Invalid If 1: Writing is executed
NOTE
A port number value can be set for the PR300 with Ethernet communication function.
Port number setting is only effective when the protocol is set to Modbus/TCP.
[Example]
To set the port number to 1024: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW02D0293,0400,D0294,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.6 Writing Energy Values

3.6.1 Active Energy

[Procedure]
(1) Write an active energy value to the two D registers in the table below. The data type is
integer.
(2) After writing that value, write 1 to the writing status register, D0373.
3-26
D Register
D0371
D0372 40372 0173
D0373 40373 0174
Reference No.
40371
H No.
0172
Description
Active energy-setpoint (lower 2 bytes)
Active energy-setpoint (upper 2 bytes)
Active energy value writing status
Effective Range
Refer to the "NOTE" below.
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the active energy value to 10,000,000 kWh: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10,000,000 is converted into a hexadecimal value, the value is 0098 9680. Then the
order of the upper two bytes and the lower two bytes is reversed ⇒ 9680 0098.
[Command] [STX] 01010WRW03D0371, 9680, D0372, 0098, D0373, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
The set active energy value range of the PR300 changes depending on the values of the VT and CT ratios. The table below shows the set value range.
[Secondary Rated Power]  [VT Ratio]  [CT Ratio]
Less than 100 kW 100 kW to less than 1 MW 1 MW to less than 10 MW 10 MW or greater
Possible Set Value Range
0 to 99999 kWh 0 to 999999 kWh 0 to 9999999 kWh 0 to 99999999 kWh
NOTE
The secondary rated power of the PR300 changes depending on its model and suffix codes.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.6.2 Regenerative Energy

[Procedure]
(1) Write a regenerative energy value to the two D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the writing status register, D0376.
3-27
D Register
D0374
D0375 40375 0176
D0376 40376 0177
Reference No.
40374
H No.
0175
Description
Regenerative energy-setpoint (lower 2 bytes)
Regenerative energy-setpoint (upper 2 bytes)
Regenerative energy writig status
Effective Range
Refer to the "NOTE" below.
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the regenerative energy value to 10,000,000 kWh: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10,000,000 is converted into a hexadecimal value, the value is 0098 9680. Then the
order of the upper two bytes and the lower two bytes is reversed ⇒ 9680 0098.
[Command] [STX] 01010WRW03D0374, 9680, D0375, 0098, D0376, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
The set regenerative energy value range of the PR300 changes depending on the values of the VT and CT ratios. The table below shows the set value range.
[Secondary Rated Power] [VT Ratio] [CT Ratio]
Less than 100 kW 100 kW to less than 1 MW 1 MW to less than 10 MW 10 MW or greater
Possible Set Value Range
0 to 99999 kWh 0 to 999999 kWh 0 to 9999999 kWh 0 to 99999999 kWh
NOTE
The secondary rated power of the PR300 changes depending on its model and suffix codes.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.6.3 LEAD Reactive Energy

[Procedure]
(1) Write a LEAD reactive energy value to the two D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the writing status register, D0381.
3-28
D Register
D0377
D0378 40378 0179
D0381 40381 017C
Reference No.
40377
H No.
0178
Description
LEAD reactive energy-setpoint (lower 2 bytes)
LEAD reactive energy-setpoint (upper 2 bytes)
Reactive energy writing status (D0377 to D0380 are validated)
Effective Range
Refer to the "NOTE" below.
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the LEAD reactive energy value to 10,000,000 kVarh: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10,000,000 is converted into a hexadecimal value, the value is 0098 9680. Then the
order of the upper two bytes and the lower two bytes is reversed ⇒ 9680 0098.
[Command] [STX] 01010WRW03D0377, 9680, D0378, 0098, D0381, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
The set LEAD reactive energy value range of the PR300 changes depending on the values of the VT and CT ratios. The table below shows the set value range.
[Secondary Rated Power]  [VT Ratio]  [CT Ratio]
Less than 100 kW 100 kW to less than 1 MW 1 MW to less than 10 MW 10 MW or greater
Possible Set Value Range
0 to 99999 kvarh 0 to 999999 kvarh 0 to 9999999 kvarh 0 to 99999999 kvarh
NOTE
The secondary rated power of the PR300 changes depending on its model and suffix codes.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.6.4 LAG Reactive Energy

[Procedure]
(1) Write a LAG reactive energy value to the two D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the writing status register, D0381.
3-29
D Register
D0379
D0380 40380 017B
D0381 40381 017C
Reference No.
40379
H No.
017A
Description
LAG reactive energy-setpoint (lower 2 bytes)
LAG reactive energy-setpoint (upper 2 bytes)
Reactive energy writing status (D0377 to D0380 are validated)
Effective Range
Refer to the "NOTE" below.
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the LAG reactive energy value to 10,000,000 kVarh: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10,000,000 is converted into a hexadecimal value, the value is 0098 9680. Then the
order of the upper two bytes and the lower two bytes is reversed ⇒ 9680 0098.
[Command] [STX] 01010WRW03D0379, 9680, D0380, 0098, D0381, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
The set LAG reactive energy value range of the PR300 changes depending on the values of the VT and CT ratios. The table below shows the set value range.
[Secondary Rated Power] [VT Ratio] [CT Ratio]
Less than 100 kW 100 kW to less than 1 MW 1 MW to less than 10 MW 10 MW or greater
Possible Set Value Range
0 to 99999 kvarh 0 to 999999 kvarh 0 to 9999999 kvarh 0 to 99999999 kvarh
NOTE
The secondary rated power of the PR300 changes depending on its type.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.6.5 Apparent Energy

[Procedure]
(1) Write an apparent energy value to the two D registers in the table below. The data
type is integer.
(2) After writing that value, write 1 to the writing status register, D0384.
3-30
D Register
D0382
D0383 40383 017E
D0384 40384 017F
Reference No.
40382
H No.
017D
Description
Apparent energy-setpoint (lower 2 bytes)
Apparent energy-setpoint (upper 2 bytes)
Apparent energy writing status
Effective Range
Refer to the "NOTE" below.
If other than 1: Invalid If 1: Writing is executed
[Example]
To set the apparent energy value to 10,000,000 kVAh: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: If 10,000,000 is converted into a hexadecimal value, the value is 0098 9680. Then the
order of the upper two bytes and the lower two bytes is reversed ⇒ 9680 0098.
[Command] [STX] 01010WRW03D0382, 9680, D0383, 0098, D0384, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
The set apparent energy value range of the PR300 changes depending on the values of the VT and CT ratios. The table below shows the set value range.
[Secondary Rated Power]  [VT Ratio]  [CT Ratio]
Less than 100 kW 100 kW to less than 1 MW 1 MW to less than 10 MW 10 MW or greater
Possible Set Value Range
0 to 99999 kVAh 0 to 999999 kVAh 0 to 9999999 kVAh 0 to 99999999 kVAh
NOTE
The secondary rated power of the PR300 changes depending on its model and suffix codes.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.7 Executing Reset Operations

3.7.1 Remote Reset

[Procedure]
(1) To execute remote reset, write data to the D register in the table below. The data type
is integer.
3-31
D Register
D0400
Initial value of remote reset: 0
Reference No.
40400
H No.
018F
Description
Remote reset
Effective Range
If other than 1: Invalid If 1: PR300 reset
NOTE
When remote reset is executed, maximum, minimum and instantaneous voltage values and maximum and instantaneous current values will be reset. Optional integra­tion is terminated if it is being performed.
Even when remote reset is executed, active energy, reactive energy, and apparent energy data as well as set parameter values are retained.
[Example]
To execute remote reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW01D0400, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
NOTE
After remote reset is executed, wait for 10 seconds or more before sending another com­mand. It takes about 10 seconds to reset. Even when PR300 was reset by power supply switch off/on, also wait for 10 seconds or more before sending another command.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.7.2 Maximum/Minimum Values Reset

[Procedure]
(1) To execute maximum/minimum values reset, write data to the D register in the table
below. The data type is integer.
3-32
D Register
D0351
Reference No.
40351
H No.
015E
[Example]
To execute maximum/minimum values reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW01D0351,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]

3.7.3 Energy Value All-Reset

[Procedure]
Description
Maximum/minimum values (D0101 to D0138) reset
Effective Range
If other than 1: Invalid If 1: Maximum/minimum values reset
(1) To execute energy value all-reset, write data to the D register in the table below. The
data type is integer.
D Register
D0352
Reference No.
40352
H No.
015F
Description
Energy value all-reset
Relevant items are as follows: Active energy (D0001, D0002) Regenerative energy (D0003, D0004) LEAD reactive energy (D0005, D0006) LAG reactive energy (D0007, D0008) Apparent energy (D0009, D0010)
If other than 1: Invalid If 1: Energy value all-reset
Effective Range
[Example]
To execute energy value all-reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW01D0352,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.7.4 Active Energy Reset

[Procedure]
(1) To execute active energy reset, write data to the D register in the table below. The
data type is integer.
3-33
D Register
D0353
Reference No.
40353
H No.
0160
Active energy (D0001 and D0002) reset
[Example]
To execute active energy reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW01D0353, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]

3.7.5 Regenerative Energy Reset

[Procedure]
(1) To execute regenerative energy reset, write data to the D register in the table below.
The data type is integer.
Description
Effective Range
If other than 1: Invalid If 1: Active energy reset
D Register
D0354
Reference No.
40354
H No.
0161
Description
Regenerative energy (D0003 and D0004) reset
Effective Range
If other than 1: Invalid If 1: Regenerative energy reset
[Example]
To execute regenerative energy reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW01D0354, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.7.6 Reactive Energy Reset

[Procedure]
(1) To execute reactive energy reset, write data to the D register in the table below. The
data type is integer.
3-34
D Register
D0355
Reference No.
40355
H No.
0162
[Example]
To execute reactive energy reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW01D0355, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]

3.7.7 Apparent Energy Reset

[Procedure]
Description
Reactive energy (D0005 to D0008) reset
Effective Range
If other than 1: Invalid If 1: Reactive energy reset
(1) To execute apparent energy reset, write data to the D register in the table below. The
data type is integer.
D Register
D0356
Reference No.
40356
H No.
0163
Description
Apparent energy (D0009 and D0010) reset
Effective Range
If other than 1: Invalid If 1: Apparent energy reset
[Example]
To execute apparent energy reset: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX] 01010WRW01D0356, 0001 [ETX] [CR]
[Response] [STX] 0101OK [ETX] [CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.8 Setting Control States

3.8.1 Integration Start/Stop

[Procedure]
(1) To execute integration start/stop, write data to the D register in the table below. The
data type is integer.
3-35
D Register
D0301
Initial value of integration start/stop: 1 (start)
Reference No.
40301
H No.
012C
Description
Integration start/stop
Relevant items are as follows: Active energy (D0001, D0002) Regenerative energy (D0003, D0004) LEAD reactive energy (D0005, D0006) LAG reactive energy (D0007, D0008) Apparent energy (D0009, D0010)
0: Stop 1: Start
Effective Range
[Example]
To execute integration start/stop: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
<For start> [Command] [STX] 01010WRW01D0301, 0001 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
<For stop> [Command] [STX] 01010WRW01D0301, 0000 [ETX] [CR] [Response] [STX] 0101OK [ETX] [CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.8.2 Optional Integration Start/Stop

[Procedure]
(1) To execute optional integration start/stop, write data to the D register in the table
below. The data type is integer.
3-36
D Register
D0302
Initial value of optional integration start/stop: 0 (stop)
Reference No.
40302
H No.
012D
Description
Optional integration start/stop Relevant D registers: D0011 to D0014
Effective Range
0: Stop 1: Start
NOTE
Optional integration start/stop can also be controlled by digital input. Once digital input is performed, it is the only means for such control. Control via communication is no longer possible until the power is turned off or remote reset is executed (see subsection 3.7.1). However, for the PR300 with demand measuring function, digital input is used to release the demand alarm. In this case, optional integration start/stop cannot be used.
[Control via communication]
START command STOP command
Digital input turned on Digital input turned off Data update
Perform integration for this duration
Time
No response to digital input requests
[Control by digital input]
Digital input turned on Digital input turned off
START
command
Perform integration for this duration
STOP
command
No response to requests via communication
Time
Data update
[Example]
To execute optional integration start/stop: For station number 01, use PC link communication (without checksum) and the random
write command as shown below:
[Command] [STX]01010WRW01D0302,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.8.3 Demand Measurement Start/Stop

[Procedure]
(1) To execute demand measurement start/stop, write data to the D register in the table
below. The data type is integer.
3-37
D Register
D0311
Initial value of demand measurement start/stop: 0 (measurement stop)
Reference No.
40311
H No.
0136
Description
Demand measurement start/stop
Relevant items are as follows: Demand power (D0043, D0044) Demand current (D0045 to D0050)
Effective Range
0: Measurement stop 1: Measurement start
NOTE
Demand measurement start/stop can also be controlled by operation key. Once the opera­tion key is used, it is the only means for such control. Control via communication is not possible until the power is turned off, or remote reset is executed (see subsection 3.7.1).
[Control via communication]
START command STOP command
Turned on by operation key Turned off by operation key
[Control by operation key]
Turned on by operation key Turned off by operation key
Perform integration for this duration
Time
Data update
No response to requests by operation key
Perform integration for this duration
Time
START
command
STOP
command
Data update
No response to requests via communication
[Example]
To execute demand measurement start/stop: For station number 01, use PC link communication (without checksum) and the random
write command as shown below: <For start>
[Command] [STX]01010WRW01D0311,0001[ETX][CR]
[Response] [STX]0101OK[ETX][CR]
<For stop> [Command] [STX]01010WRW01D0311,0000[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
Demand measurement start/stop can be performed for the PR300 with demand measuring function.
IM 77C01E01-10E
<Toc> <Ind> <3. Procedures for Setting PR300 Functions>

3.8.4 Confirmation and Release of Demand Alarm State

[Procedure]
(1) To execute confirmation and release of demand alarm state, write data to the D
register in the table below. The data type is integer.
3-38
D Register
D0312
Reference No.
40312
H No.
0137
Description
Confirmation and release of demand alarm state
Effective Range
0: Normal state 1: Alarm state
Writing 0 during alarm state clears the alarm
[Example]
To execute confirmation of demand alarm state: For station number 01, use PC link communication (without checksum) and the word-basis
read (write) command as shown below:
<For read> [Command] [STX]01010WRDD0312,01[ETX][CR] [Response] [STX]0101OK0001[ETX][CR]
<For write> [Command] [STX]01010WWRD0312,01,0000[ETX][CR] [Response] [STX]0101OK[ETX][CR]
NOTE
Confirmation and release of demand alarm state can be set for the PR300 with demand measuring function.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4. PC Link Communication Protocol

4.1 Overview

The use of PC link communication enables the PR300 to communicate with a device such as a PC or FA-M3(PLC)'s UT link module. Such a device can be used in commu­nication to read/write data from/to D registers which are internal registers of the PR300.
PLC
FA-M3 Model of UT link module: F3LC51-2N
RS-485 communication Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
4-1
Figure 4.1 Example of Connection for PC Link Communication
Hereafter, PCs are generically called “higher-level devices. In PC link communication, a higher-level device identifies each PR300 with a station
number of 01 to 99.
NOTE
The PR300 has data (D register) the unit of which is two words. When 2-word data need to be written or read, writing or reading operations must be performed for the 2­word data at the same time.
Even if data written to the D register is out of the effective range, a normal response is returned. The part of the written data within the effective range becomes effective on the PR300 when the equivalent setup change status is written for that data.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.1.1 Configuration of Command

Commands sent from a higher-level device to the PR300 consist of the following elements.
4-2
Number
of Bytes
Element STX Station
12 2 1 3 2 11
number
(ST-NO)
(1) (2) (3) (4) (5) (7) (8) (9)(6)
CPU
number
01
Time to wait
for response
0
Command Data
Variable length
corresponding
to command
(1) STX (Start of Text)
This control code indicates the start of a command. The ASCII code is 02 in hexadeci­mal.
(2) Station Number (01 to 99)
Station numbers are used by the higher-level device to identify the PR300 at the communication destination. (These numbers are identification numbers specific to individual PR300.) P1: Broadcasting mode (See subsection 4.1.4, Specifying Broad­cast")
(3) CPU number
This number is fixed to 01. The ASCII codes are 30 and 31 in hexadecimal.
(4) Time to Wait for Response
This is fixed to ‘0’. The ASCII code is 30 in hexadecimal.
(5) Command (See section 4.2, Command and Response”)
Specify a command to be issued from the higher-level device.
Checksum ETX CR
(6) Data Corresponding to Command
Specify an internal register (D register), number of data pieces, and others.
(7) Checksum
This is required if the protocol with checksum is selected for the RS-485 communica­tion protocol parameter COMM.
It converts the ASCII codes of texts between the character next to STX and the char­acter immediately before the checksum into hexadecimal values and adds them byte by byte. It then fetches the single lowermost byte of the added results as the checksum.
This column is required only for PC link communication with checksum. PC link communication without checksum does not require this 2-byte space of ASCII code.
[Example]
[STX]01010WRDD0001, 02䊐䊐 [ETX][CR] Add up the hexadecimal values of the ASCII codes of each text.
(0 : 30, 1’ : 31, ‘W’ : 57, ‘R’ : 52, ‘D’ : 44, ‘, : 2C, 2 : 32) 30+31+30+31+30+57+52+44+44+30+30+30+31+2C+30+32
=3
72
Lowermost two digits of the added results as the checksum. [STX]01010WRDD0001,0272[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
(8) ETX (End of Text)
This control code indicates the end of a command string. The ASCII code is 03 in hexadecimal.
(9) CR (Carriage Return)
This control code indicates the end of a command. The ASCII code is 0D in hexadeci­mal.
NOTE
The control codes STX, ETX”, and CR are essential for commands when you create a communication program for PC link communication. Omission of any of them or incorrect order of them results in communication failure.

4.1.2 Configuration of Response

Responses from the PR300 with respect to a command sent from the higher-level device consist of the elements shown below, which differ depending on the condition of communi­cation; normal or failure.
4-3
1) Normal Communication
When communication completes normally, the PR300 returns a character string OK and data corresponding to a command.
No parameter data area for write command.
Number of Bytes
Element STX Station
number
(ST-NO)
CPU
number
01
Variable length12 22 211
OK Parameter data Checksum ETX CR
2) In the Event of Failure
If communication does not complete normally, the PR300 returns a character string ER and error code (EC1 and EC2). (See subsection 4.1.3, Response Error Codes.)
No response is made in case of an error in station number specification or CPU number specification.
If a PR300 cannot receive ETX in a command, response may not be made.
Note: As a countermeasure, provide a timeout process in the communication functions of the higher-level device or in
communication programs.
Number
of Bytes
Element STX ER EC1 EC2 Command Checksum ETX CRStation
12 22223 211
CPU
number
(ST-NO)
number
01
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.1.3 Response Error Codes

See Also
4.1.2, Configuration of Response, for the configuration of response in the event of error.
The error codes (EC1) and detailed error codes (EC2) of responses are as follows.
Table 4.1 List of Error Codes EC1
Error Code
Command error
02
Register specification error
03
Out of setpoint range
04
(when in writing operation)
Out of data count range
05
Monitor error
06
Parameter error
08
Checksum error
42
Internal buffer overflow
43 44 The end-of-data or end-of-text character has not been received.
Character reception timeout
Meaning Cause(s)
No command exists.
Command not executable
No register number exists.
A value other than hexadecimal values (0 to 9, A to F) has been specified in word
specification.
The position of a start for a data load/save or other command is out of the address range.
The specification of the number of words is out of the specified range.
An attempt was made to execute monitoring without specifying the monitor
(WRS).
An illegal parameter is set.
The sum does not match the expected value.
A data value greater than the specified was received.
4-4
Table 4.2 List of Detailed Error Codes EC2
Meaning
03
04
05
08 Parameter error
Register specification error
Out of setpoint range
Out of data count range
Parameter number where error occurred (HEX) This is the sequence number of a parameter that first resulted in an error when counted from the leading parameter.
e.g.:
[STX]01010WRW02D0043,3F80,A0044,0000[ETX][CR]
Parameter numbers 1 2 3 4 5
[STX]0101ER0304WRW[ETX][CR]
In this case, EC1=03 and EC2=04.
Detailed Error Code (EC2)Error Code (EC1)
Register name specification error
For error codes other than those noted as EC1, there is no EC2 meaning, and 0x00 is returned as a response.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.1.4 Specifying Broadcast

The corresponding multiple PR300 perform the function to receive and process a com­mand in which this station number is specified.
(1) Specify P1 for the station number in the command to execute it. (2) This command works independently of station numbers of slave stations (01 to 99). (3) This command is applicable for writing only. (4) No response is returned from the PR300 when communication is performed using this
command.
4-5
PC
RS-485 communication
Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
Figure 4.2 Broadcasting
Broadcast data.
* No response from slave stations
[Example of Starting Optional Integrations]
Use PC link communication (without checksum) and the random write command as shown below:
[STX]P1010WRW01D0302,0000[ETX][CR]
D Register
D0302
Reference No.
40302
H No.
012D
Description
Optional integration start/stop (D0011 to D0014)
Effective Range
0: Stop 1: Start
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.2 Command and Response

The following shows the lists of commands available in PC link communication. The details of them are explained in the description of each command.
(1) Word-basis Access Commands
4-6
Command Description
WRD WWR WRR WRW
WRS
WRM
Word-basis read Word-basis write Word-basis, random read Word-basis, random write Specifies D registers to be monitored on a
word-by-word basis. Word-basis monitoring
(2) Information Commands
Command Description
INF6 INF7
Reads model, suffix codes, and version. Reads the maximum value of CPU.
Number of words to be handled
1 to 64 words 1 to 64 words 1 to 32 words 1 to 32 words
1 to 32 words
Number of units to be handled
1 1
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

WRD Reads D registers on a word-by-word basis

Function
This function code reads a sequence of contiguous register information on a word-by-word basis by the specified number of words, starting with a specified register number.
The number of words to be read at a time is 1 to 64.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
4-7
Number of
Bytes
Command
element
Number of
Bytes
Response
element
1
STX2Station
number
(ST-NO)
1
STX
2
Station
number
(ST-NO)
01
01
2
1
3
0
WRD
2
OK
4
2
dddd14dddd2
5
Register
number
1
Comma
or
space
2
Number
of words
(n)
4
ddddn
2
Checksum
2
Checksum1ETX1CR
1
ETX1CR
The response is returned in a 4-digit character string (0000 to FFFF) in hexadecimal. ddddn: read data of the specified number of words ddddn = character string in hexadecimal n = 1 to 64 words
Example
Read the active energy (register symbol: kWh L and kWh H) of the PR300 at station num­ber 01.
The register numbers for active energy are D0001 and D0002. [Command]
[STX]01010WRDD0001, 0272 [ETX] [CR]
The data of active energy (2 words) will be returned in response to the command above. [Response]
[STX]0101OK7840017D0B [ETX] [CR]
Note: To use the response data as the reading, reverse the order of the upper and lower words.
Hex 7840 017D (reversed) Hex 017D 7840 Decimal 25000000
25000000 [kWh] in decimal.
See the Note below.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

WWR Writes data into D registers on a word-by-word basis

Function
This function code writes information into a sequence of contiguous registers on a word-by­word basis by the specified number of words, starting with a specified register number.
The number of words to be written at a time is 1 to 64.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
4-8
Number
of Bytes
Command
element
Command (continued)
4
dddd2
STX
1
2
Station
number
(ST-NO)
4
ddddn
2
01
2
Checksum1ETX1CR
3
1
0
WWR
5
Register
number
1
Comma
or space
2
Number
of words
(n)
1
Comma
or space
Write information is specified in a 4-digit character string (0000 to FFFF) in hexadecimal.
ddddn: write data of the specified number of words ddddn = character string in hexadecimal n = 1 to 64 words
Number
of Bytes
Response
element
1
STX
2
Station
number
(ST-NO)
2
012OK
2
Checksum1ETX1CR
4
dddd1
Example
Write the floating point data 00004120 into the VT ratio (register symbol: VT L and VT H) and CT ratio (register symbol: CT L and CT H) of the PR300 at station number 01. The register numbers for VT ratio are D0201 and D0202. The register numbers for CT ratio are D0203 and D0204.
[Command]
[STX]01010WWRD0201,04,0000412000004120C3[ETX][CR]
OK will be returned in response to the command above. [Response] [STX]0101OK5C[ETX][CR]
Note: To use the response data as the reading, reverse the order of the upper and lower words.
VT ratio: 4-byte floating-point hex data 0000 4120 (reversed) Hex 4120 0000 Decimal 10 CT ratio: 4-byte floating-point hex data 0000 4120 (reversed) Hex 4120 0000 Decimal 10
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

WRR Reads D registers on a word-by-word basis in random order

Function
This function code reads the statuses of the individual registers, on a word-by-word basis, specified in a random order by the specified number of words.
The number of words to be read at a time is 1 to 32.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
4-9
Number of Bytes
Command
element
Command (continued)
Number of Bytes
Response
element
1
STX2Station
5
Register
number
n
1
STX2Station
number
(ST-NO)
2
Checksum
number
(ST-NO)
2
01
1
ETX1CR
2
01
1
0
WRR
2
OK
dddd14dddd2
3
4
2
Number
of words
(n)
5
Register
number
1
Comma
space
4
ddddn
1
or
2
Checksum
5
Register
number
2
The response is returned in a 4-digit character string (0000 to FFFF) in hexadecimal. ddddn: read data of the specified number of words
ddddn = character string in hexadecimal n = 1 to 32 words
Example
1
Comma
or
space
1
ETX1CR
Read the voltage-1 (register symbol: V1 L and V1 H) and current-1 (register symbol: A1 L and A1 H) of the PR300 at station number 01. The register numbers for voltage-1 are D0027 and D0028. The register numbers for current-1 are D0033 and D0034.
[Command] [STX]01010WRR04D0027,D0028,D0033,D003405[ETX][CR]
The data 800V for the voltage-1 and 50A for the current-1 will be returned in response to the command above.
[Response]
[STX]0101OK000044480000424882[ETX][CR]
800 [V] and 50 [A] in decimal. See the Note below.
Note: To use the response data as the reading, reverse the order of the upper and lower words.
Voltage-1: floating-point hex data 0000 4448 (reversed) Hex 4448 0000 ⇒ Decimal 800 Current-1: floating-point hex data 0000 4248 (reversed) Hex 4248 0000 Decimal 50
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
4-10
WRW
Writes data into D registers on a word-by-word basis in random order
Function
This function code writes register information specified for each register into the registers specified in a random order by the specified number of words.
The number of words to be written at a time is 1 to 32.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
Number
of Bytes
Command
element
Command (continued)
5
Register
number
2
1
STX2Station
1
Comma
or
space
number
(ST-NO)
4
dddd2
2
01
1
0
5
Register
number
n
3
WRW
Comma
or space
Number
of words
1
2
(n)
ddddn
5
Register
number
4
Checksum1ETX1CR
1
Comma
space
2
1
or
4
dddd1
1
Comma
or
space
Write information is specified in a 4-digit character string (0000 to FFFF) in hexadecimal. ddddn: repetition of register numbers and write information of the specified number
of words ddddn = character string in hexadecimal n = 1 to 32 words
Number
of Bytes
Response
element
1
STX2Station
number
(ST-NO)
2
012OK
2
Checksum1ETX1CR
Example
Write 1 into the remote reset (register symbol: RMT RST) and active energy reset (register symbol: kWh RST) of the PR300 at station number 01. The register number for remote reset is D0400. The register number for active energy reset is D0353.
[Command] [STX]01010WRW02D0400,0001,D0353,000171[ETX][CR]
OK will be returned in response to the command above. [Response]
[STX]0101OK5C[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
4-11

WRS Specifies the D registers to be monitored on a word-by-word basis

Function
This function code specifies the register numbers to be monitored on a word-by-word basis. Note that this command simply specifies the registers. Actual monitoring is per­formed by the WRM command after the register numbers are specified by this command.
If the volume of data is large and you wish to increase the communication rate, it is effective to use a combination of the WRS and WRM commands rather than the WRR command. If the power supply is turned off, the register numbers specified will be erased.
The number of words to be specified at a time is 1 to 32.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
Number
of Bytes
Command
element
Command (continued)
Number
of Bytes
Response
element
1
STX2Station
5
Register
number
n
1
STX2Station
number
(ST-NO)
2
Checksum
number
(ST-NO)
2
01
1
ETX1CR
2
012OK
1
0
Checksum
3
WRS
Number of words
2
2
(n)
1
ETX1CR
5
Register
number
1
1
Comma
or space
5
Register
number
2
Example
Specify that the active power (register symbol: W L and W H) of the PR300 at station number 01 is to be monitored. (This command simply specifies the registers.) The register numbers for active power are D0021 and D0022.
[Command]
1
Comma
or space
[STX]01010WRS02D0021,D00228B[ETX][CR]
OK will be returned in response to the command above. [Response] [STX]0101OK5C[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

WRM Monitors the D registers on a word-by-word basis

Function
This function code reads the information of the registers that have been specified in ad­vance by the WRS command.
Before executing this command, the WRS command must always be executed to specify which registers are to be monitored. If no register has been specified, error code 06 is returned.
For the format of response in the event of failure, see subsection 4.1.2.
The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in the command.
Command/Response (for normal operation)
4-12
Number
of Bytes
Command
element
Number
of Bytes
Response
element
1
STX2Station
number
(ST-NO)
1
STX2Station
number
(ST-NO)
01
01
2
2
1
0
WRM
2
dddd14dddd2
OK
3
4
2
Checksum1ETX1CR
ddddn
4
2
Checksum1ETX1CR
The response is returned in a 4-digit character string (0000 to FFFF) in hexadecimal. ddddn: read data of the number of words specified by the WRS command ddddn = character string in hexadecimal n = 1 to 32 words
Example
Monitor the active power (register symbol: W L and W H) of the PR300 at station number
01. (This command reads the status of the register specified by the WRS command.) [Command] [STX]01010WRME8[ETX][CR]
The data 2500 will be returned in response to the command above. [Response]
[STX]0101OK4000451CF9[ETX][CR]
Note: To use the response data as the reading, reverse the order of the upper and lower words.
Active power: floating-point hex data 4000 451C (reversed) Hex 451C 4000 Decimal 2500
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
■ ■■ ■■

INF6 Reads the model, suffix codes, and version information

Function
This function code reads the model, suffix codes, and version number of the PR300.
For the format of response in the event of failure, see subsection 4.1.2.
Command/Response (for normal operation)
4-13
Number
of Bytes
Command
element
Number
of Bytes
Response
element
Response (continued)
4
Start
register
specified for
write
refreshing*
1
The * mark indicates fields the FA-M3s UT link module refers to.
Note 1: Model and suffix code information
1
STX2Station
1
STX2Station
4
Number of
registers
specified for
write
refreshing*
0
2
01
number
(ST-NO)
2
012OK number (ST-NO)
2
Checksum1ETX1CR
3
11
0
INF26
Checksum1ETX
12
Model code:
PR300✩★
(Note 1)
Note 2: Version number and revision number
4
Version and
revision
numbers
(Note 2)
PR300–✩★䊐䊐䊐–䊐䊐
<Model>–<Suffix code>
Returns the currently selected phase and wire system
:
1: Single-phase two-wire system 2: Single-phase three-wire system 3: Three-phase three-wire system 4: Three-phase four-wire system 5: Three-phase four-wire system (2.5 element)
: Returns the currently selected input range
1: 150 V/1 A 2: 150 V/5 A 3: 300 V/1 A 4: 300 V/5 A 5: 600 V/1 A 6: 600 V/5 A
(* and are decided by the settings of the phase and wire system and the input range.) : Returns the suffix code as is
Example:
Suffix code: PR300-32333-6A-0; Selected phase and wire system: Single-phase three-wire system; and Selected input range: 300 V/5 A; then
PR300243336A
Not returned
Example: 0102 (version number + revision number)
1
CR
4
Start
Number of
register
specified for
readout
refreshing*
<Revision number> <Version number>
1
registers
specified for
readout
refreshing*
4
22
Example
To read the model, suffix code etc. of PR300 at station number 01: [Command] [STX]01010INF605[ETX][CR]
In response to this command, the following values will be returned: Phase and wire system: Single-phase three-wire system Rated input voltage/current: 300 V/5 A AC I/O function: Analog output and pulse output Communication function: Ethernet Optional measuring function: Demand measurement Phase indication format: R, S, and T indications
[Response] [STX]0101OKPR300243336R01020001002200010000E1[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

INF7 Reads the maximum value of CPU

Function
This function code refurns the maximum value of CPU of a station in PC link communica­tion.
For the format of response in the event of failure, see subsection 4.1.2.
Command/Response (for normal operation)
4-14
Number
of Bytes
Command
element
Number
of Bytes
Response
element
Note 1: The maximum value of CPU for power and energy meter is 1.
1
STX2Station
number
(ST-NO)
1
STX2Station
number
(ST-NO)
2
01
2
012OK
3
1
0
INF
maximum
value (Note1)
1
7
1
CPU
2
Checksum1ETX1CR
2
Checksum
1
ETX1CR
Example
Read the maximum value of CPU number of the PR300 at station number 01. [Command] [STX]01010INF706[ETX][CR]
The data 1 will be returned in response to the command above. [Response] [STX]0101OK
18D[ETX][CR]
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.3 Communication with Higher-level Devices

Higher-level devices are those capable of using the PC link communication protocol.

4.3.1 Communication with FA-M3 (UT Link Module)

Communication with FA-M3 is achieved by simply connecting the PR300 to a UT link module using the PC link communication protocol. Set the communication condi­tions of the PR300 identical to those of the UT link module.
PLC
FA-M3 Model of UT link module: F3LC51-2N
RS-485 communication Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
4-15
Figure 4.3 Communication with UT Link Module
The UT link module function has the following two modes, which allow you to communicate with FA-M3 without being aware of it. For more information, see the optionally available user's manual of UT Link Module (IM 34M6H25-01E).
1. Automatic mode This mode enables the instruments' fixed devices (those that cannot be specified by
the user) to be constantly refreshed by reading from them. The fixed devices are D0001 to D0022, and the read areas cannot be written to.
2. Manual mode This mode enables the instrument's devices (those that can be specified by the user)
to be constantly refreshed by reading from and/or writing to them.
See Also
The devices mentioned here are D registers. For more information on D registers, see Chapter 7.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
FA-M3's UT Link Module Setup Procedure (Example)
This section explains the procedure for setting up the FA-M3's UT link module when the Automatic mode is used.
(1) Setting Up the UT Link Module Before following the procedure, always make sure that the FA-M3's UT link module is
turned off. Then, open the inner cover and follow the setup steps described below. Configure the DIP switch of the UT link module as shown below:
Switch No. Status Description
SW1 SW2, SW3 SW4 SW5 SW6 SW7 SW8
Set the Baud Rate switch to 9600 bps.
ON ON OFF OFF Checksum: none ON Termination character: yes (CR) ON Mode: Automatic mode OFF Not used.
Data length: 8 bits Parity: none (initial value: even) Stop bit: 1 bit
4-16
Set the Communication Mode switch to 7 (Normal).
(2) Setting Up the PR300 Set the communication conditions of the PR300 as shown below: For details on how to set the conditions, see the PR300 Power and Energy Meter Uuser's
Manual (electronic manual).
Parameter Description
Communication protocol Data length Parity Stop bit Baud rate
PC link communication (without checksum) 8 bits None 1 bit 9600 bps
(3) Turn on the FA-M3.
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>

4.4 Sample Program

4.4.1 Example of BASIC Program for Send and Receive

4-17
This section shows an example of a command sending and response receiving program created with F-BASIC*
*1 PC/AT is the product of IBM Ltd. *2 F-BASIC is the product of Fujitsu Ltd.
2
for PC/AT*1 (or compatible machines).
Example of the Program Created Using F-BASIC Version 6.3
Communication Conditions Baud rate: 9600bps
Parity: None Data length: 8 bits Stop bit: 1 bit Protocol: PC link (without checksum)
STX$=CHR$(2) ‘Define ETX$=CHR$(3) ‘Define CR$=CHR$(13) ‘Define LF$=chr$(10) ‘Define RCVCHR$=””
Initialize receive character string STOPFLAG=0 ‘Initialize end flag ‘
SEND$=STX$+”01010WRDD0001,02"+ETX$
Create character string for send ‘
BAUD 0,9600 ‘Set a communication baud rate open “COM0:(F8N1N7)” as #1 ‘Open a communication port
interval 5 ‘Set timeout timer on com(0) gosub *RECEIVECHR
Specify interruption processing
during receiving
on interval gosub *TIMEOUT
Specify interruption processing
at timeout
print #1,SEND$ ‘Send com(0) on
Permit interruption during receiving
interval on ‘Start timer
while STOPFLAG=0
Wait for receive end or timeout
waiti wend
com(0) off
Permit interruption during receiving
close #1 ‘Close the port
print “>”+SEND$ ‘Display sent character string
on screen
print “<“+RCVCHR$ ‘Display received character
string on screen end ‘
IM 77C01E01-10E
<Toc> <Ind> <4. PC Link Communication Protocol>
‘=== Subroutine === *RECEIVECHR ‘Interruption processing during
receiving interval off ‘Start timer RCVCHR$=RCVCHR$+input$(lof(#1),#1) ‘Fetch character string
from receive buffer. END$=mid$(RCVCHR$,len(RCVCHR$),1) select case END$
case LF$ ‘Echo-back-capable RCVCHR$=””
Initialize receive character string case CR$ ‘Receiving end flag STOPFLAG=1 ‘Set receiving end flag case else
end select
interval on ‘Start timer return ‘ *TIMEOUT ‘Timeout processing
STOPFLAG=1 ‘Set timeout flag
RCVCHR$=”Time out ! (5 sec)”+CR$
Character string for display
on screen “Time out ! (5 sec)
return
4-18
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>
5-1

5. Modbus/RTU and ASCII Communication Protocols

5.1 Overview

The use of Modbus communication enables the PR300 to communicate with a device such as a PC or PLC (sequencer). Such a device can be used in communica­tion to read/write data from/to D registers which are internal registers of the PR300.
Hereafter, PCs are generically called “higher-level devices.
Higher-level device
RS-485 communication Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
Figure 5.1 Example of Connection for Modbus Communication
See Also
Chapter 7 for information on the D registers.
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>
For Modbus communication with the PR300, we provide the ASCII mode and RTU mode (binary system) for the transmission mode.
Table 5.1 ASCII and RTU Modes
Item ASCII Mode RTU Mode
Number of data bits 7 bits (ASCII) 8 bits (binary) Message start mark Message end mark Message length Data time intervals 1 second or less Between frames: 3.5 characters Error detection
*1: When message length in the RTU mode is assumed to be “N”, message length in ASCII mode is 2N+1”. *2: LF is a synchronization character indicating that the PR300 is ready to accept the next signal. In the RTU mode,
synchronization is achieved during the time interval between characters. If there is a period of time equivalent to 3.5 characters before the next character is received, the message being received next is recognized as a new frame.
(*1)
: (colon) None CR+LF 2N+1 N
Longitudinal redundancy check: LRC Cyclic redundancy check: CRC-16
(*2)
None
In Modbus communication, a higher-level device identifies each PR300 with a station number of 01 to 99.
NOTE
5-2
The PR300 has data (D register) the unit of which is two words. When 2-word data need to be written or read, writing or reading operations must be performed for the 2­word data at the same time.
Even if data written to the D register is out of the effective range, a normal response is returned.
IM 77C01E01-10E
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5.1.1 Configuration of Message

Messages sent from the higher-level device to the PR300 consist of the following elements.
5-3
Element
Number of bytes in RTU mode
Number of bytes in ASCII mode
Start of
Message Mark
None
1224n
(1) (3) (4) (5)(2) (6)
Station Number (ST-NO)
112n
Function
Code
Data Error Check End of
2
(variable)
22
(variable)
(1) Start of Message Mark
This mark indicates the start of a message. Note that only ASCII mode requires a colon (:).
(2) Station Number (01 to 99)
Station numbers are used by the higher-level device to identify the PR300 at the communication destination. (These numbers are identification numbers specific to individual PR300, which are expressed in hexadecimal in the message.)
00: Broadcasting mode (See subsection 5.1.5, Specifying Broadcast”)
(3) Function Code (See section 5.2, Message and Response”)
This element specifies a command (function code) from the higher-level device.
Message Mark
None
(4) Data
This element specifies D register numbers, the number of D registers, parameter values, or others in accordance with the function code. (It is expressed in hexadecimal in the message.)
(5) Error Check
In RTU mode: Carried out by the cyclic redundancy check (CRC-16) system. In ASCII mode: Carried out by the longitudinal redundancy check (LRC) system.
(6) End of Message Mark
This mark indicates the end of a message. Note that only ASCII mode requires CR + LF.
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>

5.1.2 Specifying D Registers

Specification of D registers using commercially available SCADA or other software and specification of D registers for messages used in a customer-created communi­cation program are different. Take note of this.
For a customer-created communication program, specify a value in hexadecimal that is obtained by subtracting 40001 from a reference number.
Example: Specifying D0043
For messages in the customer-created communication program, specify 002A, the hexadecimal number of value 42 obtained by subtracting 40001 from the reference num­ber.

5.1.3 Checking Errors

Modbus communication has two modes, i.e., the ASCII mode which is communication based on ASCII characters and the RTU mode which is binary code communication. These modes use different error-checking methods.
5-4
ASCII Mode
In the ASCII mode, errors are checked by means of an LRC longitudinal redundancy check.
The LRC value is the two's complement of the sum obtained by adding up data byte by byte, from the station number to the last data item, excluding ‘:’, ‘CR and LF. Ignore the carry that may occur at the upper digit when adding up the data.
Example:
The method of calculating the LRC for the [:]110300C80004[LRC][CR][LF] command for reading a series of four D registers of the device at station number 17, starting with the D00201 (VT ratio) register, is as follows:
[1] Station number 17 is 11 in hexadecimal.
Change the data to byte-by-byte hex data 11,03,00,C8,00,04. (In the Modbus/ASCII message, this data is represented by the ASCII code as two bytes, i.e., 31 and 31 in hexadecimal.)
[2] Add up the byte-by-byte hex data on a byte-by-byte basis.
11 + 03 + 00 + C8 + 00 + 04 = E0
[3] Find the two's complement of the lower one byte of the data thus added up 20
11100000 (0xE0) 00011111 (complement) + 1 = 00100000 (20)
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>
RTU Mode
In the RTU mode, errors are checked by means of a CRC-16 cyclic redundancy check. The CRC-16 value is the 16-bit remainder when the value obtained by concatenating the 8 bits of all blocks (from the station number to the last data item) of a message, excluding the start bit, stop bit and parity bit, is divided by a predetermined 17-bit binary number.
Example of CRC-16 Calculation
When executing function code 03 (reads data from multiple D registers) to read the status from the slave at station number 11 0B, send the 0B03002A0004 command.
[1] The initial value is FFFF. Find the XOR value of this initial value and the first character
(= station number 11).
[2] Refer to the lower byte of the result of executing the function code (or the upper byte, if
the result is regarded as a block of text). From the table, obtain the value correspond­ing to that byte. Since the result is F4 in this example, you refer to the 244th value in the table and obtain 8701”.
[3] Find the XOR value of the upper byte of the XOR operation in step [1] and the result of
step [2]. This value is the first character of the CRC-16 calculation.
[4] Using the result of step [3] (remainder) as the next initial value, make the same calcu-
lation to evaluate the second character (function code 03).
5-5
Initial value FF FF Station number 0B
--------­XOR FF F4 Reference to table
XOR 87 FE Function code 03
XOR 87 FD Reference to table
XOR
XOR E5 9E Last character 04
-------­XOR E5 9A Reference to table
Resulting error 6B 6
6B 80
--------
87 01
--------
--------
81 C1
-------­ 81 46
5
Convert the hex value to a decimal value, find the corresponding number in Table 5.2, and substitute the number into the formula. In the example shown on the left, hex value F4 is converted to decimal value 244. From Table 5.2, the number corresponding to 244 proves to be 8701. This number is substituted into the formula.
[5] Repeat steps [1] to [4] to perform the calculation up to the last character string 04. [6] Reverse the order of the upper and lower bytes of 6B65 and append 656B to the end
of the character string as the error code. 0B03002A0004
First reverse the order of the upper and lower bytes of the calculated result, then compare the value with the received data or store the value in the transmission buffer.
* Numbers in quotation marks are hexadecimal.
656B
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>
Table 5.2 Results of Performing CRC on 0th to 255th Values at A001
Number
0 1 2 3 4 5 6 7
Result
0000 C0C1 C181 0140 C301 03C0 0280 C241
Number
8 9 10 11 12 13 14 15
Result
C601 06C0 0780 C741 0500 C5C1 C481 0440
Number
16 17 18 19 20 21 22 23
Result
CC01 0CC0 0D80 CD41 0F00 CFC1 CE81 0E40
Number
24 25 26 27 28 29 30 31
Result
0A00 CAC1 CB81 0B40 C901 09C0 0880 C841
Number
32 33 34 35 36 37 38 39
Result
D801 18C0 1980 D941 1B00 DBC1 DA81 1A40
Number
40 41 42 43 44 45 46 47
Result
1E00 DEC1 DF81 1F40 DD01 1DC0 1C80 DC41
Number
48 49 50 51 52 53 54 55
Result
1400 D4C1 D581 1540 D701 17C0 1680 D641
Number
56 57 58 59 60 61 62 63
Result
D201 12C0 1380 D341 1100 D1C1 D081 1040
Number
64 65 66 67 68 69 70 71
Result
F001 30C0 3180 F141 3300 F3C1 F281 3240
Number
72 73 74 75 76 77 78 79
Result
3600 F6C1 F781 3740 F501 35C0 3480 F441
Number
80 81 82 83 84 85 86 87
Result
3C00 FCC1 FD81 3D40 FF01 3FC0 3E80 FE41
Number
88 89 90 91 92 93 94 95
Result
FA01 3AC0 3B80 FB41 3900 F9C1 F881 3840
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
Number
Result
96 97 98 99 100 101 102 103 2800 E8C1 E981 2940 EB01 2BC0 2A80 EA41 104 105 106 107 108 109 110 111 EE01 2EC0 2F80 EF41 2D00 EDC1 EC81 2C40 112 113 114 115 116 117 118 119 E401 24C0 2580 E541 2700 E7C1 E681 2640
120 121 122 123 124 125 126 127 2200 E2C1 E381 2340 E101 21C0 2080 E041 128 129 130 131 132 133 134 135 A001 60C0 6180 A141 6300 A3C1 A281 6240 136 137 138 139 140 141 142 143 6600 A6C1 A781 6740 A501 65C0 6480 A441 144 145 146 147 148 149 150 151 6C00 ACC1 AD81 6D40 AF01 6FC0 6E80 AE41 152 153 154 155 156 157 158 159 AA01 6AC0 6B80 AB41 6900 A9C1 A881 6840 160 161 162 163 164 165 166 167 7800 B8C1 B981 7940 BB01 7BC0 7A80 BA41 168 169 170 171 172 173 174 175 BE01 7EC0 7F80 BF41 7D00 BDC1 BC81 7C40 176 177 178 179 180 181 182 183 B401 74C0 7580 B541 7700 B7C1 B681 7640 184 185 186 187 188 189 190 191 7200 B2C1 B381 7340 B101 71C0 7080 B041 192 193 194 195 196 197 198 199 5000 90C1 9181 5140 9301 53C0 5280 9241 200 201 202 203 204 205 206 207 9601 56C0 5780 9741 5500 95C1 9481 5440 208 209 210 211 212 213 214 215 9C01 5CC0 5D80 9D41 5F00 9FC1 9E81 5E40 216 217 218 219 220 221 222 223 5A00 9AC1 9B81 5B40 9901 59C0 5880 9841 224 225 226 227 228 229 230 231 8801 48C0 4980 8941 4B00 8BC1 8A81 4A40 232 233 234 235 236 237 238 239 4E00 8EC1 8F81 4F40 8D01 4DC0 4C80 8C41 240 241 242 243 244 245 246 247 4400 84C1 8581 4540 8701 47C0 4680 8641 248 249 250 251 252 253 254 255 8201 42C0 4380 8341 4100 81C1 8081 4040
5-6
IM 77C01E01-10E
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5.1.4 Configuration of Response

The PR300 receives a command message from the higher-level device. If the received command message is found to be normal and directed at the station number of the PR300 itself, the PR300 concludes the content of the message to be normal. Thus, the PR300 enters the phase of executing message processing, deciphers the content of the command message, and processes with the message.
The PR300 does not execute message processing, however, if the received command message is found to be abnormal. In that case, the PR300 either ignores the received message or creates a response message telling the received message is erroneous.
After receiving a normal command message and executing a given process, the PR300 creates and sends a response message to which error check data appropriate for the command function code of the higher-level device is added.
Responses to Normal Messages
For a loop back function or a function for writing to a single register, the PR300 returns the received command message as a response message.
For a function for writing to multiple D registers, the PR300 returns part of the received command message as the response message.
For a readout function, the PR300 adds the read data to the ends of the station number and function code of the received command message, and returns the message as the response message.
5-7
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>
Responses to Abnormal Messages
If there is any failure other than transmission errors, the PR300 returns the following re­sponse message without executing any process:
5-8
1 2
Function
Code
(*1)
1 2
Error Code
1 2
Error
Check
2 2
Element
Number of bytes in RTU mode Number of bytes in ASCII mode
*1: The function code entered here is the function code (in hex) plus 80 (in hex).
Start of
Message
Mark (:)
None
1
Station Number (ST-NO)
The following table summarizes details on the error codes.
Error Code
01 02 Abnormal D register number 03
Funcation code error
Abnormal number of D registers
Meaning
Cause
Function code does not exist. D register number out of the range is specified. Number of D registers out of the range is specified.
The PR300 does not regard it as an error even if there is any unused register among those with consecutive register numbers specified by a readout function; rather, the PR300 returns a value of 0 in this case.
The PR300 returns the error code 02 or 03 if the specified consecutive registers are made to fall outside the given range by the number of registers specified, even though the D­register start number was initially within the range. (Depend on the function code.)
Cases when There Are No Responses to Transmitted Messages
[CR][LF]
None
2
A transmission error (overrun, framing, parity, LRC or CRC-16 error) is encountered.
The station number in the command message is wrong.
The interval between data composing a message is longer than 2 seconds.
The station number is 00 (broadcast specification).
The receiving buffer has overflowed.
Note: As a measure against the abovementioned problems, add a time-out process to the communication function or
program of the higher-level device.
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>

5.1.5 Specifying Broadcast

The corresponding multiple PR300s perform the function to receive and process a com­mand in which this station number is specified.
(1) Specify 00 for the station number in the command to execute it. (2) This command works independently of station numbers of slave stations. (3) This command is applicable for writing only. (4) No response is returned from the PR300 when communication is performed using this
command.
5-9
Higher-level device
RS-485 communication
Maximum communication distance: 1200 m Maximum number of slave stations to be connected: 31
Figure 5.2 Broadcasting
Broadcast data.
* No response from slave stations
[Example]
Write 0001 into the D0400 (remote reset) using broadcast command.
[Message] [:]0006018F000168[CR][LF]
00: broadcast addressing, 06: function code 06,018F: D register number 400, 0001: data 0001, 68: error check
* Numbers in quotation marks are hexadecimal.
No response is returned to the above message.
D-Reg No.
D0400 40400 018F Remote reset
Ref No. H No. Description Effective Range
If other than 1: Invalid If 1: PR300 is reset
NOTE
When remote reset is executed, maximum, minimum and instantaneous voltage values and maximum and instantaneous current values will be reset. Optional integra­tion is terminated if it is being performed.
Even when remote reset is executed, active energy, reactive energy, and apparent energy data as well as set parameter values are retained.
IM 77C01E01-10E
<Toc> <Ind> <5. Modbus/RTU and ASCII Communication Protocols>

5.2 Message and Response

Function codes are command words used by the higher-level device to obtain the D registers information of PR300.
Table 5.3 Function Codes
Code Function
03
Reads data from multiple D registers.
06
Writes data into D register.
08
Performs loop back test.
16
Writes data into multiple D registers.
Capable of reading data from a maximum of 64 successive D registers between D0001 and D0400.
Capable of writing data into one D register between D0001 and D0400.
Used when checking communication wiring.
Capable of writing data into a maximum of 32 successive registers between D0001 and D0400.
The write function codes cannot be written into read-only or user-prohibited D regis­ters.
Broadcast addressing is possible with function codes 06 and 16 only. (Also in this case, cannot be written into read-only or user-prohibited D registers.)
Description
5-10
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03 Reads data from multiple D registers

Function
This function code reads the contents of successive D registers by the specified number starting with a specified D registers number.
The maximum number of D registers to be read at a time is 64.
For the format of responses in the event of failure, see subsection 5.1.4.
Message (for normal operation)
5-11
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Message (continued)
Error
Check
End of Message Mark
2
2
Start of
Message
Mark (:)
None
1
(CR + LF)
None
2
Station Number (ST-NO)
1
2
Response (for normal operation)
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Response (continued)
Contents of
D Register
2
Start of
Message
Mark (:)
None
1
Error
Check
2
Station Number (ST-NO)
End of Message Mark
Function
Code
(03)
1
2
(CR + LF)
None
Function Code
1
2
(03)
Byte
Count
1
2
1
2
D-Register
Start Number
Contents of
D Register
2
4
Number of
D Registers
2
44
...
...
...
2
4
2
2
Example (ASCII mode)
Read a series of four D registers starting with the D0201 (VT ratio and CT ratio) at station number 11.
[Message] [:]0B0300C8000426[CR][LF] 0B:station number 11, 03: function code 03, 00C8: D register start number 201, 0004”: number of D registers 4, and 26: error check
* Numbers in quotation marks are hexadecimal.
The following response will be returned to the message above. [Response] [:]0B030800003F8000003F806C[CR][LF]
* The VT ratio and CT ratio data are floating point values. The combined value of D0201 and
D0202, 00003F80, represents 1. That of D0203 and D0204, which is also 00003F80, represents 1 as well (the upper four digits, 3F80, and the lower four digits, 0000, are reversed).
* The floating point value of 3F800000 is the decimal equivalent of 1.
IM 77C01E01-10E
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06 Writes data into D register

Function
This function code writes data into a specified D registers number.
The maximum number of D registers to be written into at a time is 1.
For the format of response in the event of failure, see subsection 5.1.4.
Broadcast addressing is possible (by setting 00 to the station number).
Message (for normal operation)
5-12
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Message (continued)
Write Data
(Upper Digit)
1
2
(Lower Digit)
Start of
Message
Mark (:)
None
Write Data
1
2
Station Number (ST-NO)
1
1
Error
Check
2
End of Message Mark
2
2
Response (for normal operation)
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Response (continued)
Write Data
(Upper Digit)
1
(Lower Digit)
Start of
Message
Mark (:)
None
Write Data
1
Station Number (ST-NO)
1
1
Error
Check
2
End of Message Mark
2
Function Code
(CR + LF)
None
2
Function Code
(CR + LF)
None
(06)
1
2
(06)
1
2
D-Register
Number
(Upper Digit)
1
22
D-Register
Number
(Upper Digit)
1
22
D-Register
Number
(Lower Digit)
1
D-Register
Number
(Lower Digit)
1
2
2
2
2
Example (ASCII mode)
Write 0001 into the D0302 (optional integration start/stop) at station number 11. [Message] [:]0B06012D0001C0[CR][LF] 0B: station number 11, 06: function code 06, 012D: D register number 302, 0001”:
data 0001, and C0: error check
* Numbers in quotation marks are hexadecimal.
The following response will be returned to the message above. [Response] [:]0B06012D0001C0[CR][LF]
The frame same as the message is returned.
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08 Performs loop back test

Function
This function code is used to check connection for communication.
For the format of response in the event of failure, see subsection 5.1.4.
The 00 shown below (marked with an asterisk *) are fixed.
Any value can be selected for transmit data.
Message (for normal operation)
5-13
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Message (continued)
Error
Check
End of Message Mark
2
2
Start of
Message
Mark (:)
None
1
(CR + LF)
None
2
Station Number (ST-NO)
1
2
Response (for normal operation)
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Response (continued)
Error
Check
End of Message Mark
2
Start of
Message
Mark (:)
None
1
(CR + LF)
None
Station Number (ST-NO)
1
2
Function Code
(08)
1
2
Function Code
(08)
1
2
00
0000
2
44
00
0000
2
44
Transmit Data
(Arbitrary)
2
Same as
Transmit Data
2
2
2
Diagnostic Codes
Diagnostic Code
0000
Command message return
Meaning
Data
Arbitrary
Example (ASCII mode)
Send data 0000 (fixed) and transmit data 04D2 (arbitrary) to the station number 11 to check the connection for communication.
[Message] [:]0B08000004D217[CR][LF]
When the connection is normal, the following response same as the command will be returned. [Response] [:]0B08000004D217[CR][LF]
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16 Writes data into multiple D registers

Function
This function code writes data into successive D registers by the number starting with a specified D registers number.
The maximum number of D registers to be written into at a time is 32.
For the format of response in the event of failure, see subsection 5.1.4.
Broadcast addressing is possible (by setting 00 to the station number).
No response is returned when using the broadcast addressing.
Message (for normal operation)
5-14
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Massage (continued)
Number of
D Registers
(Upper Digit)
1
22
Start of
Message
Mark (:)
None
1
Number of
D Registers
(Lower Digit)
1
Byte
Count
1
2
Station Number (ST-NO)
1
2
(Upper Digit)
Response (for normal operation)
Element
Number of bytes
in RTU mode
Number of bytes
in ASCII mode
Response (continued)
Number of
D Registers
(Upper Digit)
1
Start of
Message
Mark (:)
None
1
Number of
D Registers
(Lower Digit)
1
Station Number (ST-NO)
1
2
Error Check
2
Function
Code
(10)
End of Message
Function Code
Data
1
2
Start Number
(Upper Digit)
1
2
Mark
(CR + LF)
None
(10)
1
2
Data
(Lower Digit)
1
2
D-Register
1
22
D-Register Start
Number
(Upper Digit)
1
22
D-Register
Start Number
(Lower Digit)
1
D-Register Start
Error
Check
2
2
Number
(Lower Digit)
1
End of Message
Mark
(CR + LF)
None
2
2
2
2
2
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Example (ASCII mode)
Write 10 into a series of four D registers starting with the D0201 (VT ratio and CT ratio) at station number 11. [Message] [:]0B1000C800004120000041204F[CR][LF]
0B: station number 11, “10”: function code 16, “00C8”: D register start number 201,0004: number of D registers 4, 08: byte count (number of D registers × 2), “0000”: VT ratio lower two bytes, 4120: VT ratio upper two bytes, 0000: CT ratio lower two bytes,4120: CT ratio upper two bytes and 4F: error check
* Numbers in quotation marks are hexadecimal.
The following response will be returned to the message above. [Response]
[:]0B1000C8000419[CR][LF]
Write 1 into the D0207(setup change status) to activate the writing into the VT ratio and CT ratio. [:]0B0600CE000120[CR][LF]
0B: station number 11, “06”: function code 06, “00CE”: D register start number 207,0001: writing data 0001, and 20: error check
5-15
* Numbers in quotation marks are hexadecimal.
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6. Modbus/TCP Communication Protocol

6.1 Overview

Modbus/TCP is one of the protocol used to communicate with devices such as PCs or PLCs (sequencers) using the TCP/IP protocol via Ethernet and other networks.
This communication protocol is used to perform read/write operations with the D registers in the PR300 and exchange data with connected devices.
The PR300 can be connected to IEEE802.3-compliant networks (10BASE-T/ 100BASE-TX). Generally, the Modbus/TCP protocol communicates through port 502.
In addition, the PR300 operates as Ethernet-serial gateway. A higher-level device can exchange data with other serial communication devices using the Modbus/TCP protocol via the PR300.
Higher-level devices (PC etc.)
6-1
Application Layer Transport Layer Network Layer Data link Layer Physical Layer
Figure 6.1 Network Layer
Modbus/TCP TCP IP ETHERNET 10BASE-T/100BASE-TX
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(Example)
Higher-level device IP address [192.168.1.1] (arbitrary)
Maximum distance between hub and module: 100 m Maximum number of hubs connectable in cascade configuration: 4 levels for 10BASE-T 2 levels for 100BASE-TX
PR300 as Ethernet-serial gateway function
HUB
LAN connection
6-2
Station number 01 (fixed) IP address [192.168.1.2] (arbitrary)
RS-485 connection
Station number 02
(arbitrary)
Station number 01 (fixed) IP address [192.168.1.3] (arbitrary)
Station number 03
(arbitrary)
Station number 01 (fixed) IP address [192.168.1.4] (arbitrary)
Figure 6.2 Example of Connection for Modbus/TCP Communication
See Also
Chapter 7 for information on the D registers.
Station number 01 (fixed) IP address [192.168.1.5] (arbitrary)
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6.2 TCP/IP Communication

Modbus/TCP communicates with other devices, following the procedure below, through the TCP/IP socket interface.
PC
Ethernet
PR300 with Ethernet
communication function
6-3
Initial Setup
socket()
connect()
send()
recv()
close()
Figure 6.3 TCP/IP Communication
Open connection
Command
Response
Terminate connection
Initial Setup
socket()
bind()
listen()
accept()
recv()
send()
close()
NOTE
If no request is received from the higher-level device for more than 60 seconds after estab­lishing a connection, the PR300 will automatically terminate the connection.
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6.3 Network Frame Structure

The Modbus/TCP frame structure is as follows:
MODBUS TCP/IP ADU
MBAP Header Function code Data
PDU
MBAP Header (Modbus Application Protocol Header) : Header used to identify the Modbus/TCP protocol PDU: simple Protocol Data Unit

6.3.1 MBAP Header Structure

The MBAP Header (Modbus Application Protocol Header) consists of the following seven bytes.
Byte No01234 5 6
6-4
Description
Transaction ID: Set any value for identifying the transaction. The PR300 returns a value received from a higher-level device
Protocol ID: Specify “0” for the Modbus/TCP protocol. Number of bytes: Number of bytes after the unit ID (byte number 6) Unit ID: For the communication with the PR300 itself, specify 01 for the higher-level device. The PR300 returns 01 as a
Transaction ID
as a response.
response. For the communication with the device connected to the RS-485 communication terminals of the PR300 using the Ethernet-serial gateway function, specify its station number (02 to 99). The device returns the same value as a response.

6.3.2 PDU Structure

The PDU (simple Protocol Data Unit) consists of the following n bytes.
Byte No 0 1 to (n-1)
Description
Function code: Specify a command (function code) from a higher-level device. Data: Specify D register numbers, number of D registers, parameter values, or others in accordance with the function code.
(expressed in hexadecimal in the request)
Function code
Protocol ID Unit IDNumber of bytes
Data
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6.4 Communication with Higher-level Devices

6.4.1 List of Function Codes

The codes in the following list are command words higher-level devices use to acquire information from the internal registers (D registers) of the PR300.
6-5
Code Function
03
Reads data from multiple D registers.
06
Writes data into D register.
08
Performs loop back test.
16
Writes data into multiple D registers.
The write function codes cannot be written into read-only or use-prohibited D registers.

6.4.2 Specifying D Registers

Follow the procedures below to specify a D register from a higher-level device: (1) If using commercially available SCADA or other software, specify the Ref No. indicated
in Chapter 7, Functions and Usage of D Registers.
(2) For customer-created communication programs, specify the H No. indicated in Chap-
ter 7, Functions and Usage of D Registers.
Example: To specify D0301 as the integration start/stop, *Specify Ref. No. 40301 for a request using commercially available SCADA or other
software.
Description
Capable of reading data from a maximum of 64 successive D registers between D0001 and D0400.
Capable of writing data to one D register between D0001 and D0400.
Used when checking communication wiring.
Capable of writing data into a maximum of 32 successive register between D0001 and D0400.
*Specify H No. 012C for a request using customer-created communication program.
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6.4.3 Request and Response

03 Reads data from multiple D registers
Function
This function code reads the contents of successive D registers by the specified number starting with a specified D registers number.
The maximum number of D registers to be read at a time is 64.
For the format of responses in the event of failure, see subsection 6.4.4.
Request (for nomal operation): Reading data from n registers
6-6
Element
Number of bytes
Command
element
Hex value
MBAP Header
22 2 2211
Transaction ID
Arbitrary 0000 0006 n
Protocol ID
Number of
bytes
Unit ID
01 to 99
Function
code
03
start number
Register
PDU
Number of
registers
Response (for normal operation)
Element
Number of bytes
Command
element
Hex value
22 2 2 2111
Transaction ID
Arbitrary 0000 2n+3 03 2n
MBAP Header
Protocol ID
Number of
bytes
Unit ID
01 to 99
Function
code
Byte
count
Contents of
register 1
PDU
● ● ● ●
Example
Read a series of four D registers starting with D0201 (VT ratio and CT ratio) at station number 01.
[Request] 000100000006010300C80004
(1) (2) (3) (4) (5) (6) (7)
Contents of
register n
(1) 0001: Arbitrary 2-byte data (2) 0000: Protocol ID=0000 (fixed) (3) 0006: Number of bytes (4) 01: Unit ID = 01 indicating PR300 (5) 03: Function code 03 (6) 00C8: D register start number 201 (7) 0004: Number of D registers = 4
The following response will be returned to the request above: [Response] 00010000000B01030800003F8000003F80
* The VT ratio and CT ratio data are floating point values. The combined value of D0201 and D0202, 00003F80, represents 1. That of D0203 and D0204, which is also 00003F80, represents 1 as well (the upper four digits, 3F80, and the lower four digits, 0000, are reversed).
* The floating point value of 3F800000 is the decimal equivalent of 1.
(1) (2) (3) (4) (5) (6)
D0201 and D0202
D0203 and D0204
(1) 0001: The arbitrary 2-byte data in the request (2) 0000: Protocol ID = 0000 (fixed) (3) 000B: Number of bytes (4) 01: Unit ID = 01 indicating PR300 (5) 03: Function code 03 (6) 08: Byte count
* Numbers in quotation marks are hexadecimal.
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