Vishay VT300 Technical Manual
VT300
Weighbridge Indicator
Technical Manual
Revision A4, September 2006 Doc # TM-VT300-EN
Table of Contents
VT300 Technical Manual, Rev. A4 ii Doc # TM-VT300-EN
Table of Contents
TABLE OF CONTENTS ................................................................................ II
TABLE OF FIGURES .................................................................................VII
LEGAL NOTICE...................................................................................... VIII
WARRANTY.............................................................................................. IX
SAFETY INSTRUCTIONS.............................................................................X
DECLARATION OF CONFORMITY ............................................................. XII
ABOUT THIS DOCUMENT....................................................................... XIII
1 TECHNICAL SPECIFICATIONS......................................................... 15
1.1 GENERAL ........................................................................................... 15
1.2 ANALOG INPUT .................................................................................... 16
1.3 ANALOG OUTPUT (OPTIONAL)................................................................... 16
1.4 DIGITAL INPUT .................................................................................... 17
1.5 DIGITAL OUTPUTS ................................................................................ 17
2 INSTALLATION .............................................................................. 18
2.1 SITE REQUIREMENTS ............................................................................. 18
2.2 MOUNTING THE INDICATOR ...................................................................... 18
2.2.1 Desktop Model (Aluminum Enclosure).................................................. 18
2.2.2 Wall-Mount Model (Stainless Steel Enclosure) ....................................... 19
2.3 CONNECTING LOAD CELLS ....................................................................... 20
2.3.1 Desktop Model (Aluminum Enclosure).................................................. 20
2.3.2 Wall-Mount Model (Stainless Steel) ..................................................... 21
2.3.3 Load Cell Operating Parameters.......................................................... 21
2.4 SERIAL CONNECTIONS............................................................................ 22
2.4.1 Printer and PC Cables........................................................................ 22
2.4.2 RS485 Cable Connections .................................. ... ............................. 22
2.5 CONNECTING POWER ............................................................................. 23
Table of Contents
VT300 Technical Manual, Rev. A4 iii Doc # TM-VT300-EN
3
DISPLAY, KEYS AND MENUS........................................................... 24
3.1 THE DISPLAY ...................................................................................... 24
3.1.1 Status Annunciators............................................................. ... ... ... .... 25
3.1.2 Common Messages Shown on the Display ............................................ 25
3.2 FRONT PANEL KEYS............................................................................... 26
3.2.1 Using Keys to Perform Operations ....................................................... 26
3.2.2 Using Keys to Enter Information ......................................................... 27
3.3 THE MENU ......................................................................................... 27
3.3.1 Using the Menu ................................................................................ 27
3.3.2 Menu Structure and Options Summary................................................. 28
Main Menu........................................................................... .........................................28
Main > WEIGH ...................... ... ...... ... ...... .... ...... ... ...... ... ....... ... ... ...... ... ...... .... ...... ... ...... .28
Main > VFILE ........... ...... .... ...... ... ...... ... ...... .... ... ...... ... ...... ... ....... ... ...... ... ...... .... ...... ... ... .29
Main > TFILE .......................................... ....... ... ...... ... ...... ... ....... ... ...... ... ...... .... ...... ... ....29
Main > MISC........................................................................ ... ...... ... ... ....... ... ...... ... ...... .30
Main > SYSTEM.......................................................................... ... ... ...... ... ....... ... ...... ... .30
Main > SYSTEM (cont.) ...................................... ...... ... ...... .... ...... ... ...... ... ....... ... ...... ... ... .31
4 CALIBRATION ................................................................................ 32
4.1 SELECTING CALIBRATION METHOD ............................................................. 32
4.2 CALIBRATION WITH STANDARD WEIGHTS...................................................... 33
4.2.1 Zero (Dead-Load) Calibration ............................................................. 33
4.2.2 Span Calibration............................................................................... 33
4.3 ELECTRONIC CALIBRATION (E-CAL) ........................................................... 34
4.3.1 Calculating Calibration Values............................................................. 34
4.3.2 Setting Zero Calibration (Dead-Load) Value.......................................... 35
4.3.3 Span (Max. Capacity) Calibration ........................................................ 35
4.4 STORING CALIBRATION DATA ................................................................... 35
4.5 LOCKING AND UNLOCKING CALIBRATION....................................................... 36
4.5.1 Sealing Indicator Enclosure with Stickers............................................. . 36
4.5.2 Securing Load Receptor........................................................ ... ... ... ... . 37
4.5.3 Checking Seal Status and Audit Trail Counter.............................. ... ... ... . 37
5 GENERAL SYSTEM PARAMETERS..................................................... 38
Table of Contents
VT300 Technical Manual, Rev. A4 iv Doc # TM-VT300-EN
5.1 EDITING PARAMETERS ............................................................................ 38
5.2 SYSTEM > 1/2CAL > PAR MENU ............................................................ 39
5.2.1 Dual-scale Connecting And Parameter Settings ..................................... 41
5.3 SYSTEM > SET > OPER ...................................................................... 41
6 SERIAL COMMUNICATION.............................................................. 43
6.1 SERIAL PORTS CONFIGURATION................................................................. 43
6.1.1 RS232 Serial Port ................................. ... ... ... ... ................................ 43
6.1.2 RS485 Serial Port ................................. ... ... ... ... ................................ 43
6.2 SETTING PORT OUTPUT .......................................................................... 44
6.2.1 Setting Port 1 Output ........................................................................ 44
6.2.2 Setting Port 2 Output ........................................................................ 45
6.3 OUTPUT FORMATS................................................................................. 46
6.3.1 Continuous Weight Output ................................................................. 46
6.3.2 Continuous Weight Output with Dual Scale Operation............................. 47
6.3.3 Continuous Weight With Tare ............................................................. 47
6.3.4 Alibi Transmit................................................................................... 49
6.3.5 Alibi Mode Commands ....................................................................... 49
Transmit Displayed Weight .............................................................................................49
Command “ZERO” ............................................. ...... ... ...... ... ....... ... ... ...... ... ....... ... ...... ... .49
Character for Print-on-Demand .......................................................................................50
6.3.6 EDP Protocol Output.......................................................................... 50
6.3.7 Remote Printer Output....................................................................... 51
6.3.8 Master-Slave Protocol........................................................................ 51
Master-Slave Commands................................................................................................53
Gross-Tare-Net Weight Transmission .............................................................. .................56
6.4 DEFAULT TICKET FORMATS ...................................................................... 57
6.5 CUSTOM TICKET FORMATS ....................................................................... 58
6.5.1 Creating a Custom Ticket Format ........................................................ 58
6.5.2 Downloading and Uploading Custom Ticket Formats............................... 60
7 OUTPUTS AND DIGITAL INPUT....................................................... 62
7.1 SPECIFICATIONS .................................................................................. 62
7.1.1 Digital Outputs................................................................................. 62
Table of Contents
VT300 Technical Manual, Rev. A4 v Doc # TM-VT300-EN
7.1.2
Analog Outputs ................................................................................ 62
7.1.3 Digital Input (Tilt Switch)................................................................... 62
7.2 CONNECTING DIGITAL OUTPUTS AND TILT SWITCH .......................................... 63
7.3 SETTING THRESHOLDS FOR DIGITAL SETPOINTS.............................................. 63
7.3.1 Setpoint Options............................................................................... 64
Setpoint On/Off Combinations........................................................................................ .64
7.4 CONFIGURING ANALOG OUTPUT................................................................. 65
7.4.1 Connecting PCB and Setting Jumper.................................................... 65
7.4.2 Setting Analog Output Parameters ...................................................... 66
7.4.3 Calibrating D/A Converter ............................... ... ... .... ... ... ... ... ... .......... 67
7.5 USING THE TILT SWITCH......................................................................... 68
7.5.1 Tilt Switch Options. ... ... ... ... ... ...................................... ... ... ... ... ... ... .... 68
8 SERVICE OPERATIONS AND TESTING ............................................. 69
8.1 SERVICE OPERATIONS ............................................................................ 69
8.1.1 Setting and Changing System and Operator Password (SYSTEM > PIN).... 69
8.1.2 Setting Date, Time and Serial Number (SYSTEM > DATE)....................... 70
8.1.3 Resetting Parameters (INIT)............................................................... 70
8.1.4 Displaying Remaining Battery Capacity (WEIGH > BATTERY)................... 71
8.1.5 Checking Calibration Seal (MISC > 1/2OIML)............... ... ...................... 71
8.1.6 Viewing Load Cell mV (TEST > CVM) ................................................... 71
8.1.7 Viewing A/D Count (TEST > A/D)........................................................ 71
8.1.8 Locking and Unlocking Keys ............................................................... 72
8.2 TESTING THE INDICATOR......................................................................... 72
8.2.1 Testing ROM/RAM Integrity (TEST > MEM) ........................................... 72
8.2.2 Testing the Keypad and Display (TEST > KBD, LCD) .............................. 73
8.2.3 Testing Digital Input and Outputs (TEST > I/O)........................... ... ... .... 73
8.2.4 Testing Data Received on Both Serial Ports (TEST > PORT)..................... 74
9 SPECIAL WEIGHBRIDGE OPERATIONS ........................................... 75
9.1 CUSTOMIZING WEIGHBRIDGE DESCRIPTIONS ................................................. 75
9.2 BATCH WEIGHING ................................................................................ 76
10 TROUBLESHOOTING....................................................................... 78
Table of Contents
VT300 Technical Manual, Rev. A4 vi Doc # TM-VT300-EN
10.1 ERRORS, CAUSES AND REMEDIES............................................................... 78
10.1.1 Hardware and General Errors.............................................................. 78
10.1.2 Printing and EDP Protocol Errors ......................................................... 79
10.1.3 Weighing and Counting Errors ............................................................ 79
10.1.4 Alibi Memory and Accumulated Total Errors .......................................... 80
10.2 CHECKING LOAD CELL CONNECTION............................................................ 80
10.3 CHECKING POWER SUPPLY ....................................................................... 80
10.4 CHECKING DIGITAL OUTPUTS ................................................................... 80
APPENDIX A: TECHNICAL DRAWINGS ...................................................... 81
CONTACTING VISHAY TRANSDUCERS ...................................................... 86
Table of Figures
VT300 Technical Manual, Rev. A4 vii Doc # TM-VT300-EN
Table of Figures
F
IGURE 1 – DESKTOP MODEL, FRONT AND REAR VIEW .................................................. 18
FIGURE 2 - WALL-MOUNT MODEL, FRONT AND REAR VIEWS ............................................ 19
FIGURE 3 – LOAD CELL CONNECTION DIAGRAM FOR DESKTOP MODEL ................................. 20
FIGURE 4 – LOAD CELL CONNECTION DIAGRAM FOR WALL-MOUNT MODEL ............................ 21
FIGURE 5 – PRINTER AND PC CABLES CONNECTION DIAGRAM ......................................... 22
FIGURE 6 – RS485 CABLE CONNECTION DIAGRAM...................................................... 23
FIGURE 7 – POWER CABLE CONNECTION DIAGRAM ...................................................... 23
FIGURE 8 – NON-REMOVABLE STICKER ................................................................... 36
FIGURE 9 – LEAD WIRE SEAL / HARD PLASTIC STICKER ................................................. 36
FIGURE 10 - WALL MOUNT MODEL, SEALING INSTRUCTIONS ........................................... 37
FIGURE 11 – DIGITAL OUTPUT AND TILT SWITCH CONNECTION DIAGRAM............................. 63
Legal Notice
VT300 Technical Manual, Rev. A4 viii Doc # TM-VT300-EN
Legal Notice
This manual contains information that is proprietary to Vishay Transducers Ltd.
(“VT”). No part of this publication may be reproduced in any form whatsoever
without prior written approval by VT.
Right, title and interest, all information, copyrights, patents, know-how, trade
secrets and other intellectual property or other proprietary rights relating to this
manual and to the VT300 (“the Product”), and any software components contained
therein, are proprietary products of VT protected under international copyright law
and shall be and remain solely with VT.
VT300 is a registered trademark of VT. No right, license, or interest to such
trademark is granted hereunder, and you agree that no such right, license, or
interest shall be asserted by you with respect to such trademark.
You shall not copy, reverse compile or reverse assemble all or any portion of the
Manual or the Product. You are prohibited from, and shall not, directly or indirectly,
develop, market, distribute, license, or sell any product that supports substantially
similar functionality as the Product, based on or derived in any way from the
Product. Your undertaking in this paragraph shall survive the termination of this
Agreement.
This Agreement is effective upon your opening of the packaging of the Product,
and shall continue until terminated. VT may terminate this Agreement upon the
breach by you of any term hereof. Upon such termination by VT, you agree to
return to VT the Product and all copies and portions thereof. For further
information contact VT at the address below or contact your local distributor.
Warranty
VT300 Technical Manual, Rev. A4 ix Doc # TM-VT300-EN
Warranty
Vishay Transducers warrants all instruments it manufactures to be free from defect in materials and factory workmanship, and agrees to
repair or replace any instrument that fails to perform as sp ecified within one year after date of shipment. Coverage of computers,
cameras, rechargeable batteries, and similar items, sold in conjunction with equipment manufactured by Vishay Transducers and bearing
the identifying name of another company, is limited under this warranty to one year after the date of shipment. The warranty on non-
rechargeable batteries and similar consumable items is li mited to the delivery of goods free from defects in materials and factory
workmanship.
This warranty shall not apply to any instrument that has been repaired, worked on or altered by persons unauthorized by Vishay
Transducers in such a manner as to injure, in our sole judgment, the performance, stability, or reliability of the instrument; subjected to
misuse, negligence or accident; or connected, installed, adjusted, or used otherwise than in accordance with the instructions furnished by
us.
At no charge, we will repair, at our plant, or at an authorized repair station, or at our option, replace any of our products found to be
defective under this Warranty.
This Warranty is in lieu of any other warranties, expressed or implied, including any implied warranties of merchantability or fitness for a particular
purpose. There are no warranties which extend beyond the description on the face hereof, Purchaser acknowledges that no salesman, agent,
employee or other person has made any such presentations or warranties or otherwise assumed for Vishay Transducers any liability in connection
with the sale of any goods to the purchase. Buyer hereby waives all rights Buyer may have arising out of any breach of contract or breach of
warranty on the part of Vishay Transducers, to any incidental or consequential damages, including but not limited to damages to property,
damages for injury to the person, damages for loss of use, loss of time, loss of profits or income, or loss resulting from personal injury.
Some states do not allow the exclusion or limitation of incidental or consequential damages for consumer products, so the above
limitations or exclusions may not apply to you.
The Purchaser agrees that the Purchaser is responsible for notifying any subsequent Buyer of goods manufactured by Vishay Transducers
of the warranty provisions, limitations, exclusions and disclaimers stated herein, prior to the time any such goods are purchased by such
Buyer, and the Purchaser hereby agrees to indemnify and hold Vishay Transducers harmless from any claim asserted against or liability
imposed on Vishay Transducers occasioned by the failure of the Purchaser to so noti fy such Buyer. This provision is not intended to afford
subsequent Purchasers any warranties or rights not expressl y granted to such subsequent Purchasers under the law.
Vishay Transducers reserves the right to make any changes in the design or construction of its instruments at any time, without incurring
any obligation to make any change whatever in units previously delivered. Vishay Transducers’ sole liabilities, and Buyer’s sole remedies,
under this agreement shall be limited to the purchase price, or at our sole discretion, to the repair or replacement of any instrument that
proves, upon examination, to be defective, when returned to our factory, transportation prepaid by the Buyer, within the applicable period
of time from the date of original shipment. Return transportation charges of repaired or replacement instruments under warranty will be
prepaid by Vishay Transducers.
Vishay Transducers is solely a manufacturer and assumes no responsibility of any form for the accuracy or adequacy of any test results,
data, or conclusions which may result from the use of its equipment.
The manner in which the equipment is employed and the use to which the data and test results may be put are completely in the hands of
the Purchaser. Vishay Transducers shall in no way be liable for damages consequential or incidental to defects in any of its products.
This warranty constitutes the full understanding between the manufacturer and buyer, and no terms, conditions, understanding or
agreement purporting to modify or vary the terms hereof shall be binding unless hereafter made in writing and signed by an authorized
official of Vishay Transducers.
Safety Instructions
VT300 Technical Manual, Rev. A4 x Doc # TM-VT300-EN
Safety Instructions
The following instructions serve as a general guide for the safe operation and
maintenance of the VT300.
Safety Symbols
This symbol indicates potential safety hazards regarding product operation
or maintenance to operator or service personnel.
General Safety Practices
Do not touch or tamper with the power supply when the power cord is connected.
Line voltages may be present even when the product is powered off or a fuse is
blown.
Before working on equipment connected to power lines or to other devices, remove
jewelry or any other metallic object that may come into contact with energized
parts.
The product is intended to be grounded during normal use. Grounding is provided
by connecting the mains plug to a wall socket with a protective earth terminal. The
earth lug provided on the product should be connected to the protective earth at
all times, by a wire with a diameter of 18AWG or wider.
Always connect the ground first and disconnect it last. Do not connect data cables
to ungrounded equipment. Make sure that all other cables are disconnected before
disconnecting the ground.
Special Safety Warnings
Welding on or in the vicinity of the equipment is strictly prohibited.
Use reliable lightening conductors to prevent static loads caused by
thunderstorms.
Safety Instructions
VT300 Technical Manual, Rev. A4 xi Doc # TM-VT300-EN
Connection of AC Mains
Make sure that the electrical installation complies with local codes. Always connect
the AC plug to a wall socket with a protective ground.
The maximum permissible current capability of the branch distribution circuit that
supplies power to the product is 16A. The circuit breaker in the building installation
should have high breaking capacity and must operate at short-circuit current
exceeding 35A.
Always connect the power cord first to the equipment and then to the wall socket.
If the power cord cannot be readily disconnected in case of emergency, make sure
that a readily accessible circuit breaker or emergency switch is installed in the
building.
Operating Environment
Ambient
Temperature
Storage temperature: -10C to +70C (14F to 158F).
Operating temperature: -10C to +40C (14F to 104F).
Humidity 40% to 90% RH (non condensing).
Vibration Severe vibration can affect the accuracy of weighing and damage components.
Air The air surrounding the product should be dust-free and should not contain
corrosive gasses or other materials that could adversely effect the product.
Electromagnetic
Fields
Heavy electrical equipment should not be installed near to the weighing
apparatus.
Incoming and
Outgoing Signals
Relays and contacts connected to the equipment must have reliable and
effective interference suppression. This also applies to other equipment within
3 meters of the equipment.
Declaration of Conformity
VT300 Technical Manual, Rev. A4 xii Doc # TM-VT300-EN
Declaration of Conformity
Non-Automatic Weighing Instrument (III)
Manufacturer Vishay Transducers
Type/Model VT300
EC Type Approval
Certificate Number
DK 0199.62
Corresponds to the production model described in the EC Type Approval Certificate
and to the requirements of the Council Directive 90/384/EEC as amended and to
the requirements of the following EC Directives:
EN 45501:1994, The Metrological Aspects of Non-Automatic Weighing Machines.
EN 55022:1987, Limits and Methods of Measurement of Radio Interference
Characteristics of Information Technology Equipment.
EN 60950:1992, Safety of Information Technology Equipment.
Date
April 30, 2004
Signature
Benny Shaya, Director R&D/Operations Instruments
Being the responsible person employed and appointed by Vishay Transducers.
About this Document
VT300 Technical Manual, Rev. A4 xiii Doc # TM-VT300-EN
About this Document
This document provides technical information for the VT300 Weighbridge Indicator.
It is intended for technical staff, and explains how to install, set up and configure
the indicator, as well as troubleshoot and service it.
For information on how to use the product, see the VT300 User’s Guide.
Chapters and Their Contents
1 Technical
Specifications
General indicator specifications; analog input/output
specs; and digital input/output specs.
Pg. 15
2 Installation Installing and connecting the indicator. Pg. 18
3 Display, Keys and
Menus
Using the VT300 display, keypad and menus;
detailed outline of menus, submenus and options.
Pg. 24
4 Calibration Performing standard weight calibration and
electronic calibration.
Pg. 32
5 General System
Parameters
General parameters in the SYSTEM > 1/2CAL > PAR,
SYSTEM > SET > OPER and SYSTEM > PRP menus.
Pg. 38
6 Serial Communication Setting up communication with printers, host PCs
and other external devices.
Pg. 43
7 Outputs and Digital
Input
Connecting and using the digital input (tilt switch),
digital outputs (setpoints) and analog output.
Pg. 62
8 Service Operations
and Testing
How to set a PIN number, set date and time, view
load cell mV, test the keypad and display, and
perform other service and testing operations.
Pg. 69
9 Special Weighbridge
Operations
Customizing weighbridge descriptions, and
performing batch weighings.
Pg. 75
10 Troubleshooting and
Service
Errors, causes and suggested corrective actions;
maintenance and service instructions.
Pg. 78
About this Document
VT300 Technical Manual, Rev. A4 xiv Doc # TM-VT300-EN
Style Conventions
Verdana
Regular text.
Arial Bold
Commands, keys and other parts of the user interface.
Arial Italics
Names of classes, methods, arguments, exceptions, properties, etc. Also used
for special terms, the first time they appear.
Monospace
Text displayed on the LCD or on a computer attached to the product.
Notes, which offer an additional explanation or a hint on how to overcome a
common problem.
Warnings, which indicate potential safety hazards regarding product operation
or maintenance to operator or service personnel.
Technical Specifications
General
VT300 Technical Manual, Rev. A4 15 Doc # TM-VT300-EN
1 Technical Specifications
1.1 General
CPU MCU 89C51RD, 64KB Flash ROM, 1KB RAM, 64KB serial EEPROM, real-time clock.
Communication • Serial port 1: RS232C Full duplex, 2400 baud, 1 start, 7 data bits/even parity
or 8 data bits/no parity.
• Serial port 2: (optional): RS232 or RS485 half duplex, 2400-57600 baud, no
or even parity, 7 or 8 data bits.
Display 16 character LCD display (14.5mm height).
Annunciators Net, no motion, minus sign, zero, range 1 and 2.
Keyboard 27-key membrane type with tactile feedback.
Approvals EU type approval, 10,000 divisions, 0199.62.
Accuracy class III.
Resolution Selectable up to 990.000dd (in accordance with regulations).
Max tare effect Full scale (100%).
Auto zero track Off or 0.5dd, setup-selectable.
Weight digits 4, 5 or 6.
Weight steps 1, 2, 5, 10, 20, 50, 100, 200.
Digital filter FIR automatically adjusted to conversion speed, plus post filtering (rolling
average of 1, 2, 4, 8, 16, 32 samples).
Calibration methods Dead load, span and scale parameters via keyboard commands. Calibration can
be performed either by weighing or by entering load cell mV values.
Self diagnostics Hardware and software – MCU watchdog.
Memory failure and I/O failure – program check.
Technical Specifications
Analog Input
VT300 Technical Manual, Rev. A4 16 Doc # TM-VT300-EN
1.2 Analog Input
A second analog input may be added as an option, if no analog output is
needed. The same specifications apply.
Load cell excitation ±5V switched polarity or +5VDC with sense.
Connection 6-wire technique. Max 10 load cells, 350Ohm each.
Signal range -0.25 to 1.75mV (Gain=10), -0.25 to 3.75mV (Gain=20).
Sensitivity • Approved scales: min 0.4µV / digit (VSI).
• Non-approved scales: min 0.1µV / digit.
Input amplifier Input noise 0.3µVp-p, input bias current 10nA typical.
A/D Converter Sigma delta 550.000 internal counts max. Conversion speed: 3, 7, 14, 28, 57,
70Hz (selectable).
Linearity Within 0.002% of full scale.
Span temp coefficient
≤ 2ppm/°C.
Zero temp coefficient
≤ 2ppm/°C.
Long-term stability 0.005% of full scale per year.
1.3 Analog Output (Optional)
If no analog output is needed, a second analog input may be added (see 1.2
above). Analog Output is Powered by an external 24VDC (See section 7.1.2 for
specification).
Current or voltage
Selected via jumper JP1 on printed circuit board 761 (see section 7.4.1).
Current output 0-20mA or 4-20mA. Max load resistance 1KΩ (line + termination).
Voltage output 0.02-10V. Min load resistance 1KΩ.
Resolution • Internal: 16 bits.
• External: 16 bits, or in accordance with regulation.
Linearity Better than 0.01% of FSR.
Thermal stability 50ppm/°C typical.
Short-circuit
protection
25mA indefinite duration.
Technical Specifications
Digital Input
VT300 Technical Manual, Rev. A4 17 Doc # TM-VT300-EN
1.4 Digital Input
Input voltage 9-24VDC, positive common, optoisolated to 2.5kV.
Input resistance 3.3KΩ.
On delay 2msec max.
Off delay 2msec max.
1.5 Digital Outputs
Output voltage 24VDC ±10% transistor (source) darlington, positive common.
Max current 100mA, leakage current 100µA.
Max off-state voltage 30VDC.
On delay 2msec max.
Off delay 2msec.
Installation
Site Requirements
VT300 Technical Manual, Rev. A4 18 Doc # TM-VT300-EN
2 Installation
2.1 Site Requirements
The mounting location must be a stable surface, free of vibrations, heat or humidity.
Avoid direct sunlight on the front of the instrument. The unit should be placed at the
correct height to allow easy reading of the display and convenient keyboard
operation.
2.2 Mounting the Indicator
2.2.1 Desktop Model (Aluminum Enclosure)
All connections to the instrument are made through the rear panel connectors. Strainrelief clamps should be used. The shield should be connected to the metal frame of
the connector. The rear of the VT300 desktop model is shown in Figure 1.
Figure 1 – Desktop model, front and rear view
Installation
Mounting the Indicator
VT300 Technical Manual, Rev. A4 19 Doc # TM-VT300-EN
2.2.2 Wall-Mount Model (Stainless Steel Enclosure)
Front and rear views of the unit are shown in Figure 2.
Figure 2 - Wall-mount model, front and rear views
To connect the indicator to the stainless steel wall-mount:
1. Remove the rear panel and lift it carefully.
2. Insert the cables via the cable glands. Strip and connect the cables, as detailed in
sections 2.3, 2.4 and 2.5.
3. Connect the cable shield, either between the plastic and the metal case of the cable
glands, or to the screws supporting the PCBs.
4. Re-install the rear panel.
Installation
Connecting Load Cells
VT300 Technical Manual, Rev. A4 20 Doc # TM-VT300-EN
2.3 Connecting Load Cells
2.3.1 Desktop Model (Aluminum Enclosure)
Use 6 x 0.5mm2 shielded cable for load cell connections. Connect the load cells
according to the diagram below.
Figure 3 – Load cell connection diagram for des kto p model
1 2 3 4 5 6 7
+ - I1 CI O1 O2 +Co
LOAD CELL 1
Pin Description
1 Excitation (-)
2 Sense (-)
3 Sense (+)
4 Excitation (+)
5 Signal (-)
6 Signal (+)
D-Type Metal Case
(Shield)
7
8
Calibration
Enable
COM 2
COM 1
Load Cell 2
or
Analo
g
Output
Load Cell 1
DB9 fem
DB9 male
DB15
fem/male
DB15 fem
L
OAD CELL 2 (DB15 F)
Pin Description
1 Excitation (-)
2 Sense (-)
3 Sense (+)
4 Excitation (+)
5 Signal (-)
6 Signal (+)
D-Type Metal Case
(Shield)
Installation
Connecting Load Cells
VT300 Technical Manual, Rev. A4 21 Doc # TM-VT300-EN
2.3.2 Wall-Mount Model (Stainless Steel)
Use 6 x 0.5mm2 shielded cable for load cell connections. Connect the load cells
according to the diagram below.
Figure 4 – Load cell connec tion diagram for wall-mou nt model
2.3.3 Load Cell Operating Parameters
The load cell utilization ranges are listed in the table below.
Excitation 5VDC, fixed or alternating polarity (setup-selectable) for 10 load cells of 350Ω
each.
Gain / input ranges • For load cell output of 10mV, gain permitted is between -0.25 and 1.75mV/V.
• For load cell output of 20mV, gain permitted is between -0.25 and 3.75mV/V.
The load cells must be chosen so that the input signal to the controller is at
least 0.4µV per scale increment. For load cell output less than 0.4µV/digit, the
controller will still be stable but the full temperature range accuracy is not
guaranteed.
Do not run signal cables together with power cables. Connect the shielding only
where indicated in the drawing. Never use a Megger to check wiring. Never use
plastic insulating tape on load cell connections.
+
POWER
¯
JP1
+
INPUT
¯
OUT1
OUT2
COM
TX RX
SGND
SHIELD
+ SIG
– SIG
+ EX
+ SEN
- SEN
- EX
PCB 801
PCB
765
SHLD
+SIG
–SIG
+EX
+SEN
–SEN
–EX
7 6 5
4
3 2 1
7 6 5
4
3 2 1
7 6 5
4
3 2 1 3 2
1
Installation
Serial Connections
VT300 Technical Manual, Rev. A4 22 Doc # TM-VT300-EN
2.4 Serial Connections
For RS232C connection, use 3 x 0.34mm
2
shielded cable.
For RS485 connection, use 2 x 0.34mm
2
shielded twisted pair cable.
2.4.1 Printer and PC Cables
Figure 5 – Printer and PC cables connection diagram
Only the aluminum enclosure has a DB9 connector. The steel enclosure has a
screw terminal on the internal card, to which you should attach the individual
wires.
2.4.2 RS485 Cable Connections
The terminal block on the RS485 board enables connecting two pairs of wires (A, B):
One wire pair for connecting the incoming cable.
A second wire pair for a daisy-chain connection to the next unit on the RS485
bus.
Max 15m
Max 15m
T
o
PC
DB25 Female
Printer DB25 Male
DB9
Metal
Case
3
5
2
3
5
2
DB9
Fem
DB9
Metal
Case
DB9
Fem
Shield
TX GRN
GND BRN
DTR WHI
Shield
TX GRN
GND BRN
DTR WHI
GRN RX
BRN GND
WHI
DTR
GRN RX
BRN GND
WHI
DTR
RX
GND
T
X
RX
GND
DTR
3
7
20
2
5
3
3
7
2
3
7
2
Printer DB25 Male
OR
T
o
Serial
Printer
DB9 Female OR
Installation
Connecting Power
VT300 Technical Manual, Rev. A4 23 Doc # TM-VT300-EN
The RS485 cabling configuration is illustrated in Figure 6 below.
Figure 6 – RS485 cable connection diagram
2.5 Connecting Power
VT300 indicators are powered by 85-265VAC, via an internal power supply board. The
mains power cable is supplied with the instrument.
Power should be isolated from other data processing equipment.
Verify that the AC power socket outlet is properly protected. For optimum EMC
performance, keep the length of cable shielding inside the enclosure as short as
possible.
Figure 7 – Power cable connection diagram
1 2 3 4 5 6 7
+ - I1 CI O1 O2 +Co
Pin Description
1
2
Power
9-15 VDC
3 Input 1
4
Input
Common (-)
5 Output 1
6 Output 2
7
Output
Common (+)
COM 2
COM 1
Load Cell 2
or
Analog Outp ut
Load Cell 1
DB9 fem
DB9 male
DB15
fem/male
DB15 fem
Network
Biasing
Resistors
Chassis
Earth
470R
150
R
470R
A
B
RT
+V
White
Shield
Slave #1
(
VT x00)
Slave #2
(
VT x00)
(Up to 30
slaves)
…
Slave #30
(VT x00)
A
B
A
B A B
RT
120R
Termination
Resistor
2X0.34mm2 twisted pair shielded
Max cable length: 1000m
Maste
r
Display, Keys and Menus
The Display
VT300 Technical Manual, Rev. A4 24 Doc # TM-VT300-EN
3 Display, Keys and Menus
The VT300 front panel can be divided into four areas:
A sixteen-character dot matrix display shows weight information, status
information, and the names of menus and functions.
The function keypad, with ten orange keys, allows you to turn the unit on and off
and perform the most common operations.
A navigation area (to the right of the display) allows you to access and navigate
the menu, which contains more advanced operations.
An alphanumeric keypad, with 12 green keys, allows you to enter numbers and
letters.
3.1 The Display
The VT300 has an LCD display. There are three status annunciators on the left of the
display and two more on the right of the display. Small dots (status annunciators) may
appear next to one or more of these, to show status information such as whether the
scale has been tared or not.
Display, Keys and Menus
The Display
VT300 Technical Manual, Rev. A4 25 Doc # TM-VT300-EN
3.1.1 Status Annunciators
There are several icons at the left of the display. A dot shows up next to these to
indicate the current status of the scale or indicator. Status annunciators are often
important to understand what is being shown on the display.
Stable
Active – the scale is stable (necessary for ZERO, T and PRINT).
Inactive – the scale is not stable.
Center of Zero Active – the current weight is at center of zero (or at manual zero).
Inactive – the scale is above or below center of zero.
Net Weight Active – the display is showing net weight.
Inactive – the display is showing gross weight.
S1
Scale 1 Appears on the right of the display to show that the indicator is set to scale 1.
S2
Scale 2 Appears on the right of the display to show that the indicator is set to scale 2.
S0
Sum of Scales Appears on the right of the display to indicate that the display shows the sum of
the weight on scales 1 and 2.
W1 The scale is currently in weight range 1.
W2 The scale is currently in weight range 2.
3.1.2 Common Messages Shown on the Display
Message type Meaning
352.0
Weight of the item on the scale.
24509
Approximate number of units on the scale.
319.0
(
active)
Net weight, or number of units calculated after subtracting the container’s weight.
OVER RANGE
Over range. The item on the scale weighs more than the maximum capacity of the
scale, or the load cell signal is too high.
UNDER RANGE
Under range. The item on the scale weighs less than the minimum capacity of the
scale, or the load cell signal is too low.
E15: PWRUP
ZERO
An error has occurred (see section 10.1.1). In some cases, you can ignore the error
and continue working by pressing ESC.
xxxxxx
Software model number, shown during the power-up sequence.
xxxxxx
Software version issue date, shown during the power-up sequence.
ZERO SCALE
Automatic zeroing, performed at the end of the power-up sequence.
Other types of messages may be shown when you perform specific operations, such
as editing the tare value or displaying battery status.
Display, Keys and Menus
Front Panel Keys
VT300 Technical Manual, Rev. A4 26 Doc # TM-VT300-EN
3.2 Front Panel Keys
The keys on the VT300 front panel can serve two functions:
Performing common operations and accessing the menu.
Entering alphanumeric information.
3.2.1 Using Keys to Perform Operations
Key Description Related operations Refer to
Press to zero the scale*. Only works within the zero
range.
Manual zeroing User’s Guide,
section 3.1
Press once to tare the scale*. Press again to view
gross weight.
Taring using current
weight
User’s Guide,
section 3.2
Press to enter a preset tare. Enter the tare value
using the alphanumeric keypad and press ENTER. To
cancel and view gross weight, press ESC.
Preset tare User’s Guide,
section 3.3
When you press this key, the current weight* is
printed to the printer, output to an attached
computer, and added to the accumulated total.
Printing
Section 6.2.1
Press to switch between Weighing Mode and
Counting Mode.
Counting pieces,
weighing
User’s Guide,
chapters 4, 6
Press to turn the indicator on, or to switch it off
when it is running.
Starting the indicator -
Press to perform a first weighing of a vehicle with
unknown tare.
Weighing, printing User’s Guide,
section 5.1.2
Press to weigh a vehicle with known tare, or to
perform a second weighing.
Weighing, printing User’s Guide,
chapter 5
Toggles between scale 1, scale 2 and the sum of
both scales (if two scales are connected).
Two-scale operation -
Enters the menu. The arrows around this button allow you to navigate the
menu.
Section 3.3
Cancels the current operation, exits a menu or exits
a mode.
- -
* If the scale is not stable, the current weight cannot be used for this operation.
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