YOKOGAWA UT150L User manual

User’s
Manual Model UT150L
Communication Functions
IM 05C01E22-10E
IM 05C01E22-10E
3rd Edition

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IM 05C01E22-10E
FD No. IM 05C01E22-10E
3rd Edition: Jun. 2004 (YK)
AllRights Reserved. Copyright © 2000. Yokogawa Electric Corporation
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 communi-
cation 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.

IM 05C01E22-10E
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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.
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 exaggerated,
simplified, or partially omitted for reasons of convenience when explaining them.
(2) Figures and illustrations representing the controller’s displays may differ from the real displays in
regard to the position and/or indicated characters (upper-case or lower-case, for example), to the
extent that they do not impair a correct understanding of the functions and the proper operation and
monitoring of the system.

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IM 05C01E22-10E
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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IM 05C01E22-10E
Contents
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

IM 05C01E22-10E 1-1
Chapter 1 Setup
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.
*
Communication programs should be created referring to the documentation of each higher-level device.
●For UT150L connection
3
4
5
3
4
5
B(+)
A(-)
SG
Shield
RSB(+)
RSA(-)
SG
RSB(+)
RSA(-)
SG
UT150L UT150L
PC, PLC, or graphic panel
Grounding resistance of no greater than
100Ω
Grounding resistance of no greater than
100Ω
Terminating
resistor
220Ω
1/4 W
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
Stop bit
Address
Parity
PC link communicationProtocol selection
MODBUS communication
Baud rate
Note 1: When “3: ASCII mode”is selected for M
ODBUS communication in protocol selection, the data length is fixed to “7.”
When “4: RTU mode”is selected, it is fixed to “8.”
Data length
Symbol
ADR
PSL
PRI
DLN
BPS
STP 1, 2
0: 2400, 1: 4800, 2: 9600
0: none, 1: even, 2: odd
Setting Range
1 to 99
7, 8 (Note 1)
0: without sum check
1: with sum check
3: ASCII mode
4: RTU mode
2: 9600
1
8
Default
1
0
1: EVN
●Protocol-by-Protocol Default Parameter Settings
Note: Circled numbers denote fixed values.
PSL BPS PRI STP DLN
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
Parameter
Communication Protocol
●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 commu-
nication port is limited to 31.
Example of connecting four UT150L to a host device by setting address numbers of 1, 50, 10, and 20
ADR=1 ADR=10
Maximum overall cable length of 1200 m for a maximum of 31 substations
ADR=20ADR=50
Personal computer
●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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IM 05C01E22-10E 2-1
Chapter 2 Communication Specifications
2. Communication Specifications
The RS-485 communication interface has the PC link communication, and the MODBUS communica-
tion.
Table 2-1 UT150L Communication Protocol
Communication Protocol
Specifications
Communication Hardware
Terminal
Maximum Baud Rate
2-wire RS-485 communication system
PC link communication without sum check
PC link communication with sum check
MODBUS communication (ASCII mode)
MODBUS communication (RTU mode)
Terminal numbers: 3-5
9600 bps
Table 2-2 Types of Devices to be Connected
Device to be Connected
PC
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
Communication protocol
Synchronization
Communication system
Maximum communication distance
Standard
Item
Maximum number of devices to be connected
Baud rate
EIA RS-485 compliant
2-wire, half duplex
31
Specifications
2400, 4800, 9600
Asynchronous (start-stop)
1200 m
No-protocol

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IM 05C01E22-10E 3-1
Chapter 3 PC Link Communication
3. PC Link Communication
3.1 Overview
Maximum overall cable length of 1200 m for a maximum of 31 substations
Personal computer
Figure 3-1 Connection of Slaves in PC Link Communication
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.”
See Also
Chapters 5 and 6 for information on the D registers and I relays.
In the PC link communication, a host device identifies each UT150L with a communication address of
1 to 99. Some of commands to use let you to specify broadcast that requires no address numbers. For
more information on broadcast specification, see subsection 3.2.2.

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3.1.1 Configuration of Command
Commands sent from a host device to UT150L, consist of the following elements.
Number of
Bytes
Element
1
STX
2
Address
number
(ADR)
2
CPU
number
01
1
Time to
wait for
response
0
3
Command
Variable length
Data corresponding
to command
2
Checksum
1
ETX
1
CR
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(1)STX (Start of Text)
This control code indicates the start of a command. The character code is CHR$(2).
(2)Address Number (01 to 99)
Address numbers are used by the host device to identify UT150L at the communication destination.
(They are identification numbers specific to the UT150L.)
(3)CPU Number
This number is fixed to 01.
(4)Time to Wait for Response
This is fixed to 0.
(5)Command (See subsection 3.2.1, List of Commands)
Specify a command to be issued from the host device.
(6)Data Corresponding to Command
Specify an internal register (D register or I relay), number of data pieces, UT150L parameter value,
and others.
(7)Checksum
This converts the ASCII codes of texts between the character next to STX and the character immedi-
ately before the checksum into hexadecimal values and adds them byte by byte. It then fetches the
single lowermost byte of the added results as the checksum.
This column is only required for PC link communication with checksum. PC link communication
without checksum does not require this 2-byte space of ASCII code.
(8)ETX (End of Text)
This control code indicates the end of a command string. The character code is CHR$(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
PV high and low limits, target setpoints, and oth-
ers
Proportional bands, upper and lower limits of
output, and others
Bias, deviation alarms, and other
Type of Data
Various modes, alarm types, and others
Contents of Data
Measuring range width (EUS) data
Measuring range (EU) data
% data (0.0 to 100.0%)
Seconds, absolute values, and data
without unit
Specified Form
Numeric data not including the deci-
mal point
Numeric data not including the deci-
mal 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 Target setpoint: 50.0
*
The position of the decimal point for “500”is determined by the DP (position of decimal point) parameter of the UT150L.
3.1.2 Configuration of Response
Responses from UT150L with respect to a command sent from the host device consists of the ele-
ments 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
1
STX
2
Address
number
(ADR)
2
CPU
number
01
Variable length
Parameter data
2
Checksum
1
ETX
1
CR
2
OK
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.)
• 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
1
STX
2
Address
number
(ADR)
2
CPU
number
01
3
Command
2
Checksum
1
ETX
2
EC1
2
EC2
1
CR
2
ER

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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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Chapter 3 PC Link Communication
3.2.1 List of Commands
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)Bit-basis Access Commands Dedicated to I Relays
Command
BRD
BWR
BRW
BRR
BRS
BRM
Description
Bit-basis, random write
Bit-basis read
Specifies I relays to be monitored on a bit-by-bit basis.
Bit-basis, random read
Bit-basis write
Bit-basis monitoring
1 to 32 bits
1 to 16 bits
1 to 48 bits
1 to 16 bits
Number of Bits to be Handled
1 to 16 bits
—
(2)Word-basis Access Commands
Command
WRD
WWR
WRW
WRR
WRS
WRM
Description
Word-basis, random write
Word-basis read
Specified internal registers to be monitored on a word basis
Word-basis, random read
Word-basis write
Word-basis monitoring
1 to 32 words
1 to 16 words
1 to 32 words
1 to 16 words
Number of Bits to be Handled
1 to 16 words
—
(3)Information Command
Command
INF
Description
Reads model, presence/absence of option, and revision. 1
Number of Devices to be Handled

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3.2.2 Specifying Broadcast
The personal computer sends data to all of the substations at one time.
Note: The substations do not give any response.
Host controller (master station)
Maximum overall cable length of 1200 m for a maximum of 31 substations
Figure 3-2 Specifying Broadcast
The broadcast function enables all of the connected UT150L or other devices to receive a command.
Specifying an address number in Table 3-3 for the address number column in a command enables the
host device to write data from/into the internal registers of all UT150L or other devices.
For UT150L, internal registers (D registers and I relays) are assigned with numbers for management.
(See chapters 5 and 6 for details.) For the internal registers of other models, see the documentation of
the relevant model.
Table 3-2 Address Numbers
ADR
BG
Applicable Devices
UT150L and UT100 Series