Yokogawa UT150L Operating Manual

User’s Manual

Model UT150L Communication Functions

IM 05C01E22-10E

3rd Edition

Introduction

This instruction manual describes the communication functions of the UT150L controller and contains information on how to create communication programs.

Read the manual carefully to understand the communication functions of the UT150L.

The UT150L controller has the following communication protocols.

1) PC link communication protocol

2) MODBUS communication protocol

Note that the UT150L controller cannot communicate with a host device with a communication protocol other than these.

■ Intended Readers

This manual is intended for people familiar with the functions of the UT150L Controller and control engineers and personnel in charge of maintaining instrumentation and control equipment.

You are required to understand as a background knowledge the communication specifications of higher-level devices, in regard to their communication hardware, language used for creating communication programs, and so on.

■ Related Documents

The following instruction manuals all relate to the communication functions. Read them as necessary. The codes enclosed in parentheses are the document numbers.

• Model UT150L Limit Controller (IM 05C01E22-01E) Explains the basic operation of the UT150L controller. Supplied with the UT150L Limit Controller.

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Documentation Conventions

■ Symbols

The following symbols are used in this manual.

●Symbols Used in the Main Text

CAUTION

Draws attention to information that is essential for understanding the operation and/or features of the product.

NOTE

Gives additional information to complement the present topic and/or describe terms specific to this document.

Notices

■ Regarding This Instruction Manual

(1) This manual should be passed on to the end user. Keep at least one extra copy of 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 tran-

scribed 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.

■ 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, make certain that all of the instructions and precautions relating to safety contained in this

document are strictly adhered to. 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

CAUTION

This symbol on the product indicates that the operator must refer to an explanation in the instruction 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 electrical 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.

Functional 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 mentioned 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) Use this software with one specified computer only. You must purchase another copy of the

software for use on each additional computer. (6) Copying this software for purposes other than backup is strictly prohibited. (7) Store the floppy disk(s) (original medium or media) containing this software in a secure place. (8) Reverse engineering such as the disassembly or decompilation of software is strictly prohibited. (9) 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.

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Introduction........................................................................................................................... i

Documentation Conventions............................................................................................... ii

Notices ................................................................................................................................. iii

Chapter 1. Setup ............................................................................................................. 1-1

1.1 Setup Procedure .............................................................................................. 1-1

1.2 Notes on Setting Parameters ........................................................................... 1-2

Chapter 2. Communication Specifications................................................................... 2-1

2.1 RS-485 Communication Specifications .......................................................... 2-1

Chapter 3. PC Link Communication ............................................................................ 3-1

3.1 Overview ......................................................................................................... 3-1

3.1.1 Configuration of Command ..................................................................... 3-2

3.1.2 Configuration of Response ...................................................................... 3-3

3.2 Communication with Host Device.................................................................. 3-4

3.2.1 List of Commands ................................................................................... 3-5

3.2.2 Specifying Broadcast ............................................................................... 3-6

3.2.3 Commands ............................................................................................... 3-7

3.2.4 Response Error Codes ........................................................................... 3-20

3.3 Example of BASIC Program for Send and Receive .................................... 3-21

Chapter 4. MODBUS Communication......................................................................... 4-1

4.1 Overview ......................................................................................................... 4-1

4.1.1 Configuration of Message ....................................................................... 4-2

4.2 Communication with Host Device.................................................................. 4-3

4.2.1 List of Function Codes ............................................................................ 4-3

4.2.2 Specifying Broadcast ............................................................................... 4-4

4.2.3 Function Codes ........................................................................................ 4-5

4.2.4 Response Error Codes ............................................................................. 4-9

Chapter 5. Functions and Usage of D Registers .......................................................... 5-1

5.1 Overview of D Registers ................................................................................. 5-1

5.2 Interpretation of Lists of D Registers

(D Register Map Tables) ................................................................................. 5-1

5.3 Classification of D Registers .......................................................................... 5-2

5.4 Register Map Table ......................................................................................... 5-3

5.4.1 D Register Contents ................................................................................. 5-4

Chapter 6. Functions and Usage of I Relays ............................................................... 6-1

6.1 Status I Relays................................................................................................. 6-1

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Appendix Table of ASCII Codes (Alphanumeric Codes)...................................App. 1

Revision Record .................................................................................................................... i

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1. Setup

This chapter describes the setup procedure required to be able to use the communication functions (PC link, and MODBUS) and the communication parameters of the UT150L.

1.1 Setup Procedure

Set up the communication functions on the UT150L as follows:

Set up the communication function parameters of the UT150L. (See Section 1.2.)

Connect a higher-level device and a UT150L. (See the connection diagram below.)

Create communication programs for the higher-level device to perform communication.

Chapter 1 Setup

Communication programs should be created referring to the documentation of each higher-level device.

● For UT150L connection

PC, PLC, or graphic panel

B(+)

Terminating resistor 220Ω 1/4 W

Grounding resistance of no greater than 100Ω

A(-)

Shield

UT150L UT150L

RSB(+)

RSA(-)

Grounding resistance of no greater than 100Ω

RSB(+)

RSA(-)

Terminating resistor 220Ω 1/4 W

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1.2 Notes on Setting Parameters

This section describes the setting parameters for using the communication functions and their setting ranges.

NOTE

The details of UT150L communication functions need to be the same as those of the communication functions of the host devices to be connected. Check the communication parameters of the host device first, then set up those of the UT150L.

Table 1-1 Parameters to be Set for Communication Functions

Parameter Name

Symbol

Setting Range

Default

PSL

Address Baud rate Parity

Stop bit Data length

Note 1: When “3: ASCII mode” is selected for M When “4: RTU mode” is selected, it is fixed to “8.”

ADR BPS PRI

STP 1, 2 DLN

PC link communicationProtocol selection

MODBUS communication

1 to 99 0: 2400, 1: 4800, 2: 9600 0: none, 1: even, 2: odd

7, 8 (Note 1)

ODBUS

communication in protocol selection, the data length is fixed to “7.”

0: without sum check 1: with sum check

3: ASCII mode 4: RTU mode

● Protocol-by-Protocol Default Parameter Settings

PSL BPS PRI STP DLN

Communication Protocol

PC-link communication without sum check 0 9600 EVN 1 8 PC-link communication with sum check 1 9600 EVN 1 8 MODBUS communication (ASCII mode) 3 9600 EVN 1 7 MODBUS communication (RTU mode) 4 9600 EVN 1 8

Note: Circled numbers denote fixed values.

Parameter

1 2: 9600 1: EVN

1 8

1-2

● Protocol selection (PSL)

Set the same communication protocol as that of the host device to be connected. The UT150L has PC link communication, and MODBUS communication functions.

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Chapter 1 Setup

● Address number (ADR)

Set the address number of the UT150L itself. An address number of 1 to 99 may be assigned in any order. There is however one limitation — the number of UT150L to be connected to a single communication port is limited to 31.

Example of connecting four UT150L to a host device by setting address numbers of 1, 50, 10, and 20

Personal computer

Maximum overall cable length of 1200 m for a maximum of 31 substations

ADR=1 ADR=10

ADR=20ADR=50

● Baud rate (BPS)

Set the same communication rate as that of the host device to be connected. (Otherwise, proper communication cannot be achieved.) The unit of the communication rate is bps (bits per second).

● Parity (PRI)

Set the handling of parity to be carried out when data is sent or received. Set the same parity state as that of the host device to be connected.

● Stop bit (STP)

Set the same stop bit as that of the host device to be connected.

● Data length (DLN)

Set the same data length as that of the host device to be connected. (When MODBUS communication (PSL: 3 or 4) is chosen in protocol selection, the data length is fixed.)

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Chapter 2 Communication Specifications

2. Communication Specifications

The RS-485 communication interface has the PC link communication, and the MODBUS communication.

Table 2-1 UT150L Communication Protocol

Communication Hardware Terminal Communication Protocol

Specifications

Maximum Baud Rate

2-wire RS-485 communication system Terminal numbers: 3-5 PC link communication without sum check

PC link communication with sum check MODBUS communication (ASCII mode) MODBUS communication (RTU mode)

9600 bps

Table 2-2 Types of Devices to be Connected

Device to be Connected

Communication Protocol

PC link communication MODBUS communication

Example of Connected Devices

General-purpose PCs General-purpose PCs

2.1 RS-485 Communication Specifications

Table 2-3 RS-485 Communication Interface

Item

Standard Maximum number of devices to be connected Communication system Synchronization Communication protocol Maximum communication distance Baud rate

EIA RS-485 compliant 31 2-wire, half duplex Asynchronous (start-stop) No-protocol 1200 m 2400, 4800, 9600

Specifications

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2-2

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3. PC Link Communication

3.1 Overview

Chapter 3 PC Link Communication

Personal computer

The use of PC link communication enables UT150L to communicate with a device such as a PC, easily. In this communication, you can use such device to read/write data from/into D registers or read data from I relays, both of which are internal registers of the UT150L.

Hereafter, PCs, are generally called “host devices.”

3.1.1 Configuration of Command

Commands sent from a host device to UT150L, consist of the following elements.

Number of

Bytes

Element

STX2Address

number

(ADR)

(1) (2) (3) (4) (5) (6) (7) (8) (9)

CPU

number

Time to wait for

response

Command

Variable length

Data corresponding

to command

Checksum1ETX1CR

(1)STX (Start of Text)

This control code indicates the start of a command. The character code is CHR$(2).

(2)Address Number (01 to 99)

Address numbers are used by the host device to identify UT150L at the communication destination. (They are identification numbers specific to the UT150L.)

(3)CPU Number

This number is fixed to 01.

(4)Time to Wait for Response

This is fixed to 0.

(5)Command (See subsection 3.2.1, List of Commands)

Specify a command to be issued from the host device.

(6)Data Corresponding to Command

Specify an internal register (D register or I relay), number of data pieces, UT150L parameter value, and others.

(7)Checksum

This 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 only required for PC link communication with checksum. PC link communication without checksum does not require this 2-byte space of ASCII code.

(8)ETX (End of Text)

This control code indicates the end of a command string. The character code is CHR$(3).

(9)CR (Carriage Return)

This control code indicates the end of a command. The character code is CHR$(13).

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.

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Chapter 3 PC Link Communication

● Data Form of Commands

The table below shows the data forms of commands for D registers and I relays.

Table 3-1 Data Forms of Commands for D Registers and I Relays

Type of Data

PV high and low limits, target setpoints, and others

Bias, deviation alarms, and other

Proportional bands, upper and lower limits of output, and others

Various modes, alarm types, and others

Contents of Data

Measuring range (EU) data

Measuring range width (EUS) data

% data (0.0 to 100.0%)

Seconds, absolute values, and data without unit

Specified Form

Numeric data not including the decimal point

0 to 1000

Absolute values not including the decimal point

● Command Format for Communication

Example: When setting a target setpoint “50.0” to a UT150L, the host device sends the value “500” as command data without the decimal point (this is true for both setting 5.00 or 500).

Data to be send from the host device: hexadecimal value of 500 (01F4)

Command data: 01F4 Response data from UT150L: 01F4

UT150L side

The position of the decimal point for “500” is determined by the DP (position of decimal point) parameter of the UT150L.

Target setpoint: 50.0

3.1.2 Configuration of Response

Responses from UT150L with respect to a command sent from the host device consists of the elements shown below, which differ depending on the condition of communication; normal or failure.

1) Normal Communication

When communication is complete normally, UT150L return a character string “OK” and when the read commands, return read-out data.

Number of

Bytes

Element

2) In the Event of Failure

If communication is complete abnormally, UT150L return a character string “ER” and error code (EC1 and EC2). (See subsection 3.2.4, Response Error Codes.)

STX2Address

number

(ADR)

number

CPU

Variable length

Parameter data2Checksum1ETX1CR

•

No response is made in case of an error in address number specification or CPU number specification.

• If a UT150L cannot receive ETX in a command, response may not be made. * As a measure against those, provide a timeout process in the communication functions of the host

device or in communication programs.

Number of

Bytes

Element

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STX2Address

number

(ADR)

CPU

number

EC12EC2

Command2Checksum1ETX

3.2 Communication with Host Device

In PC link communication, when specifying D registers or I relays, the internal registers of UT150L, you can use their numbers as is. The specifications of the number of each internal register are:

• D registers: D**** (****: numeric value)

• I relays: I**** (****: numeric value)

Host devices to be connected to UT150L are those capable of handling the PC link communication protocol.

As an example of communication program, Section 3.3 shows an example of BASIC program created using Microsoft Quick BASIC.

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