A&D AD-8551R User manual

1WMPD4003931
AD-8551R
AD-8551
R
Modbus
RTU Convertor
Modbus
R
TU Convertor

This manual and Marks
All safety messages are identified by the following, “WARNING” or
“CAUTION”, of ANSI Z535.4 (American National Standard Institute: Product
Safety Signs and Labels). The meanings are as follows:
WARNING
A potentially hazardous situation which, if not avoided,
could result in death or serious injury.
CAUTION A potentially hazardous situation
which, if not avoided,
may result in minor or moderate injury.
This is a hazard alert mark.
This manual is subject to change without notice, at any time, to improve the
product.
The contents of the product specifications and this manual are subject to
change without any obligation on the part of the manufacturer.
Under the copyright laws, the software (program) described in this manual is
copyrighted, with all rights reserved.
The software may be installed into one computer and may not be installed
into other computers without the prior written consent of A&D Company,
Limited. Copying includes translation into another language, reproduction,
conversion, photocopy and offer or loan to another person.
2019 All rights reserved.
No part of this publication may be reproduced, transmitted, transcribed, or
translated into any language in any form by any means without the written
permission of A&D Company, Limited.

Contents
1. Introduction............................................................................................................................................................2
Features...........................................................................................................................................................2
Cautions...........................................................................................................................................................3
2. Composition and Names .......................................................................................................................................4
AD-8551R ........................................................................................................................................................4
Accessories......................................................................................................................................................4
3. Specifications ........................................................................................................................................................5
Dimensions ......................................................................................................................................................5
Applicable models............................................................................................................................................6
4. Power Terminal......................................................................................................................................................7
Power-supply voltage ......................................................................................................................................7
Connecting example........................................................................................................................................8
Internal connection status................................................................................................................................8
5. RS-485 Interface ...................................................................................................................................................9
RS-485 specifications......................................................................................................................................9
Connections...................................................................................................................................................10
6. RS-232C Interface...............................................................................................................................................11
RS-232C specifications .................................................................................................................................11
Connecting cable...........................................................................................................................................11
7. Switch ..................................................................................................................................................................12
How to operate the switch .............................................................................................................................12
Factory setting ...............................................................................................................................................12
RS-485 function settings ...............................................................................................................................13
RS-232C function settings.............................................................................................................................15
Fixed decimal point function..........................................................................................................................16
8. LED (status, error display)...................................................................................................................................17
9. Communicaiton in Modbus RTU Mode ...............................................................................................................18
Preparing for communication ........................................................................................................................19
Data address .................................................................................................................................................20
Detailed information on Holding Register 1...................................................................................................21
Detailed information on Holding Register 2 （only for AD-4212C/AD-4212D）..............................................................22
Communication format ..................................................................................................................................23
Operating example (When connected to the AD-4212C/AD-4212D) ...........................................................25
10. Communication in Command Mode..................................................................................................................27
Preparing for communication ......................................................................................................................27
Communication format ................................................................................................................................28
11. Troubleshooting .................................................................................................................................................29
Modbus RTU mode communication check..................................................................................................29
Command mode communication check ......................................................................................................30

2
1. Introduction
Thank you for purchasing the AD-8551R Modbus RTU convertor.
Please read this manual completely before using the AD-8551R.
Features
The AD-8551R converts the RS-232C communications of the weighing device into RS-485 (Modbus RTU)
communications (RS-232C/RS-485 converter). Use of the RS-485 enables the collection of data control of up to 31
weighing devices (addresses ranging from 1 to 63) by a single PLC.
■The RS-485 communication method of the AD-8551R can be used by selecting either Modbus RTU communication
(Modbus RTU mode) or ASCII code command communication (command mode).
■The measurement value can be reset to zero (re-zero) by operation from the PLC or PC.
■When connected to an AD-4212C and AD-4212D, etc., it is possible to change the response speed, perform
calibration with an external weight, and supply power from the weighing device.
■The hooks on the back of the AD-8551R allow one-touch mounting on a DIN rail.
RS-232C
communication
Weighing device
Weighing device
AD-8551R
Weighing device
RS-485
communication
Host
(PLC, PC, etc.)
AD-4212C, etc.
・ ・ ・
・ ・ ・
AD-8551R
AD-8551R
・ ・ ・
RS-232C
communication
RS-232C
communication

3
Cautions
Before use, confirm the following articles for safe operation.
Grounding The Convertor
Be sure to ground this convertor. (For the internal connection status of AD-8551R, refer to “4-3 Internal connection
status”.
Separate this earth ground line from others, like ground line of a motor, inverter or a power source. Unless the
convertor is grounded, it may result in receiving an electric shock, cause operation error or catch fire.
Proper Power Source And Power Cable
Confirm the AC voltage, frequency and power tolerance of the power cable (refer to “4. Power Terminal”). If the
voltage range of the cable is lower than the power line voltage, it may cause leakage or catching fire. Use pole
compression terminals to connect the power cable to the terminals.
Splashing Water
The module is not water-resistant type.
Flammable Gas
Do not install the convertor where flammable gas is present.
Heat Radiation Of The Module
Space out instruments to radiate heat sufficiently.
Do not use in an environment where the ambient temperature exceeds the operating temperature range [-10℃to
+50℃, 85% RH or less (no condensation)].
This unit is covered with a transparent plastic protective cover at the time of shipment.
After installing and connecting, be sure to remove the protective cover before turning on the power.
If it is used without removing the protective cover, this unit will overheat.
The protective cover is for preventing the entry of wire scraps and the like during installation and connecting.
Do not remove it until installation and connecting are complete.
This unit
Protective cover
This unit with a protective cover
Protective cover
This unit
①
②
Remove the two tabs on the lower
surface of the protective cover and
remove the protective cover.
How to remove the protective cover

4
2. Composition and Names
AD-8551R
Accessories
■Simplified instruction manual
■RS-485 connector (power clamp wire mount socket)
Model : AX-35505-6200-A （Made by 3M 35505-6200-A00 GF）
Front panel side
DIN rail mounting example
DIN rail groove
DIN rail (width 35mm)
Rear panel side
Pull down when removing
from DIN rail
DIN rail hook
Vent hole
Vent hole
DIN rail groove
RS-232C connector
DC power connector
RS-485 connector
LED (Status display part)
Switch

5
3. Specifications
Voltage requirement ：12 to 24 VDC [+ 10%, -15%]
Power requirement：2W Max
Communication interface：RS-485 (Modbus RTU or command for connection to control equipment)
Refer to “5-1 RS-485 specifications”
:RS-232C interface (For connection to weighing device)
Refer to “6-1 RS-232C specifications”
Communication connector：5 pin (male)：Made by 3M 35605-5153-A00 (For RS-485 interface)
D-Sub 9 pin (male) (For RS-232C interface)
Operating condition ：-10℃to + 50℃, Max 85% RH (no condensation)
External dimensions：35 (W) x 110 (H) x 101 (D)
Mass ：Approximately 170g
Accessory ：RS-485 connector (power clamp wire mount socket) 1 piece
Dimensions
110
35.3 100
39.4
34.5
36.1
(3.5)
20°
1.3
28
5.5
Unit：mm

6
Applicable models
■Functions available for each model, accessories needed for connection to AD8551R.
Accessories needed to connect the AD8551R
to a weighing device Modbus RTU
Command
mode
⋆１
Convenient functions
Weighing device
output options
Cable needed for
connection between
weighing device and
AD8551R
Data that can be read from the host Operations that can be made from the host Power supply
from the
weighing
device
Auto power on
function⋆２
Weighing
value
Status
information
Response
speed Calibration status Calibration weight value Re-zero Zero Taring Calibration with internal weight
Calibration with your
own weight
Changing
the
display
digit
Changing the
response
speed
Changing
the unit
AD4212C Unnecessary Cable included with the
weighing device ○○○○○○× × × ○○○× ○⋆３ ○○
AD4212D
⋆6
Connector for
A&D’s external
display
Unnecessary Cable included with the
weighing device ○○○○○○× × ○○○○× ○○
Connector for the
PC/PLC
Unnecessary AX-KO4472-1000 ○× ○
AD4212A/B Unnecessary AX-KO1710-200 ○△⋆４ × × × ○× × × × ○× × ○× ○
GX-A Unnecessary AX-KO2466-200 ○△⋆４ × × × ○○○○× ○× ○○○○
GF-A Unnecessary AX-KO2466-200 ○△⋆４ × × × ○○○× × ○× ○○○○
FZi, HR-AZ Unnecessary AX-KO2466-200 ○△⋆４ × × × ○× × ○× ○× ○○○○
FXi, HR-A Unnecessary AX-KO2466-200 ○△⋆４ × × × ○× × × × ○× ○○○○
GX, GX-K, GP Unnecessary AX-KO1710-200 ○△⋆４ × × × ○× × ○× ○× ○○× ○
GF, GF-K, GP Unnecessary AX-KO1710-200 ○△⋆４ × × × ○× × × × ○× ○○× ○
ＢＭ, GH Unnecessary AX-KO2466-200 ○△⋆４ × × × ○× × ○× ○× ○○× ○
HR-i Unnecessary AX-KO2466-200 ○△⋆４ × × × ○× × × × ○× ○○× ○
GR Unnecessary AX-KO1710-200 ○△⋆４ × × × ○× × ○× × × ○○× ○
HR
HR-03
(Included with
weighing device）
AX-KO1710-200 ○△⋆４ × × × ○× × × × ○× ○○× ○
FC-i Unnecessary AX-KO2466-200 ○△⋆４ × × × × ××× × × × × ○× ×
HC-i HC-03i AX-KO1786-200 ○△⋆４ × × × × ○○× × × × × ○× ×
Eki, Ewi Unnecessary AX-KO2466-200 ○△⋆４ × × × ○× × × × × × ○○× ×
EJ, EJ-B EJ-03 AX-KO2466-200 ○△⋆４ × × × 〇× × × × × × ○○× ×
EK-L Unnecessary AX-KO2466-200 ○△⋆４ × × × 〇× × × × × × ○○△⋆５ ×
HV-CWP HVW-03CWP AX-KO3285-320 ○△⋆４ × × × × 〇〇× × × × ○○× 〇
HV-C, HV-CP,
HW-C, HW-CP HVW-03C AX-KO2466-200 ○△⋆４ × × × ×〇〇× × × × ○○× 〇
HV-G, HW-G,
HW-WP Unnecessary AX-KO1786-200 ○△⋆４ × × × ×〇〇× × × × ○○× ×
FG FG-23 / FG-24 AX-KO1786-200 ○△⋆４ × × × × 〇〇× × × × × ○× ×
FS-i FS-03i AX-KO3285-320 ○△⋆４ × × × ×〇〇× × × × ○○× ×
SC/SE SCE-03 AX-KO3285-320 ○△⋆４ × × × 〇× × × × × × × ○× ×
SW SW-03 AX-KO3285-320 ○△⋆４ × × × × 〇〇× × × × ○○× ×
⋆１．When transferring a large amount of data from a weighing device all at once (GLP output, batch output of data memory, etc.), data may be lost.
⋆２．If the weighing device does not have an auto power-on function or auto-start function, it is necessary to turn on the display or each weighing device by key operation after turning on the power.
⋆３．When using the AD4212C in command mode, it is necessary to change to internal settings in advance to enter key mode.
Also, control characters beginning with “@” output from the AD4212C are not output from the AD8551R to the RS-485 side.
⋆４．Some functions (calibration error flag) cannot be used.
⋆５．Power can be supplied from the weighing device when the adapter is connected to the weighing device.
⋆６．The AD4212D has two types of RS-232C connectors. When using in Modbus RTU mode, connect the connector for A&D’s external display, and when using in command mode, connect the connector for PC/PLC and RS-232C connector of the
AD8551R.

7
4. Power Terminal
When connected to the AD-4212C / AD-4212D, power can be supplied from the weighing instrument (RS-232C
connector). No power connecting is required (Refer to “6. RS-232C Interface”).
Power-supply voltage
Connect a constant voltage of external power supply (+ 10% -15%) within the range of 12 to 24 VDC to the DC power input
terminal.
●Do not use at a voltage exceeding the rated voltage range (12 to 24 VDC +10%-15%)
・Doing so may cause failure or heat generation.
・This unit may not operate normally.
●Ground the FG terminal of the switching power supply used for the power supply of this unit.
●The power line of this unit should be dedicated for this unit, and be separate from other drive devices.
・If strong noise is generated from the power line of another device, this unit may be damaged.
・This unit may not start normally due to the inrush current of other drive devices.
・Depending on the circuit configuration of this unit, other drive devices may not operate normally.
●Select a switching power supply capacity of approximately 2W per unit for the dedicated power supply line for this
unit.
・If the power capacity is insufficient, this unit may not operate normally.
■Connector：DC power input terminal
Signal name
Description
DC+
Power supply 12 to 24V input
0V
Power supply 0V input
FG
Frame ground
DC+
0V
FG
Caution

8
Connecting example
To insert or remove the wire, press the button part of the connector with a screwdriver or the like.
Modifying the tip of the wire with a bar-type crimp terminal or the like recommended.
Connection conductor specifications
Clamping range (rating)
0.20 mm
2
to 1.5 mm
2
Applicable wire
AWG
AWG24 to AWG16
Solder plated wire
0.2 mm
2
to 1.5 mm
2
Stranded wire
0.2 mm
2
to 1.5 mm
2
Bar crimp terminal DIN 46228 Part 1
0.25 mm
2
to 1.5 mm
2
Bar crimp terminal
(With color) DIN 46228 Part 4
0.25 mm
2
to 0.75 mm
2
Length
8 mm
Internal connection status
Power wire
Button part to push when inserting and
removing.
Bar crimp terminal
DC power input terminal
Approx. 820k
Ω
SLD(5)
Shell
FG(1)
0V(2)
RS-232C
RS-485
Din rail connection
Spring pin
AD-8551R