Adam Equipment CBC SERIES User manual

@Adam Equipment Company 2005
Adam Equipment
CBC SERIES
SERVICE MANUAL
ADAM EQUIPMENT CO. LTD.
p.n. 4329, Rev. A3, January 2005

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CONTENTS
1.0 INTRODUCTION........................................................................................................... 4
2.0 TROUBLE SHOOTING GUIDE ..................................................................................... 5
3.0 ERROR CODES............................................................................................................ 6
4.0 CBC DESCRIPTION ..................................................................................................... 7
5.0 CBC PARAMETERS AND CALIBRATION (VER. 1.2- 2.02) ......................................... 8
5.1 CBC PARAMETERS (VER. 1.2- 2.02)....................................................................... 8
5.2 CBC CALIBRATION (VER. 1.2- 2.02)........................................................................ 9
6.0 FACTORY PARAMETERS (VERSION 1.1-1.8 TO 1.2- 2.02) ..................................... 10
7.0 TWO POINT FACTORY CALIBRATION ..................................................................... 10
8.0 LOAD CELL DAMAGE ................................................................................................ 11
9.0 CBC RS-232 INTERFACE........................................................................................... 14
10.0 SCHEMATICS............................................................................................................. 16

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1.0 INTRODUCTION
The CBC series of scales are general purpose counting scales.
Refer to the Operators Manual for details of operation.
This manual will cover details of calibration and troubleshooting.
If you have a problem with the scales that is not directly addressed by this manual then
contact your dealer or Adam Equipment for more assistance.
In order to supply further assistance we will need the following information:
Name of your company:
Contact Name:
Contact telephone, e-mail, fax or other methods:
Model number of the scales:
Serial number:
Software revision number (displayed when power is first turned on):
Brief description of the problem:
Include any recent history of the scale. For example-
Has it been working since it’s delivered
Water entered
Damaged from a fire
Electrical Storms in the area
Dropped on the floor, etc.

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2.0 TROUBLE SHOOTING GUIDE
PROBLEM POSSIBLE CAUSE
Display is blank Power Switch is faulty or not turned on
No turn on test Battery is faulty or not charged
Power supply is incorrect
Display all zeros after turn on Pan not installed
or E6 is displayed Unstable weight
Load cell damaged
Electronics faulty
‘- - - - -‘ appears on display Maximum capacity exceeded
Load Cell damaged
Electronics is faulty
Display is unstable Drafts or air currents
Obstruction under pan
Sample is moving (animal weighing)
Vibrations through table
Temperature changed dramatically
Electronics faulty
Battery low
Weight value incorrect Calibration error, Recalibrate
Unit calibrated with inaccurate weight
Balance not level
Obstruction between sample and cover
Wrong unit of weight displayed
Cannot use Full Capacity Over-load Stops hitting pan support or hitting
bottom of load cell
Electronics faulty
Parameters set incorrectly
Load Cell Damaged
Not Linear Overload stops hitting too soon
Faulty Factory calibration
Off Centre Loading error Overload Stops not correct
Obstruction under pan
Battery will not charge Charging circuit failure
Battery Failure
Incorrect adapter (below 800 mA)
Processor failure

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3.0 ERROR CODES
ERROR CODE DESCRIPTION POSSIBLE CAUSES

Initial Zero is greater than allowed
(typically 4% of the maximum
capacity) when power is turned on
or when the [Zero] key is pressed,
Weight is on the pan when
turning the scale on.
Excessive weight on the pan
when zeroing the scale.
Improper calibration of the
scale.
Damaged load cell.
Damaged Electronics.

Keyboard error. Improper operation of the scale.

A/D count is not correct when
turning the scale on. Platform is not installed.
Load cell is damaged.
Electronics is damaged.
 or 

or  for
some softwares 
Calibration error. Improper calibration (should be
within + 10% of the factory
calibration). The old calibration
data will be retained until the
calibration process is complete.

Scale is unstable. There is vibration or draft
making the scale unstable.
Electronics may be damaged.

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4.0 CBC DESCRIPTION
The CBC scales have an enclosure with all components mounted within it. To gain access to
the components remove the 4 screws securing the cover to the base.
The basic unit consists of:
Base
Load Cell frame
Power switch
Main PCB assembly
Battery
Display PCB assembly
Keypad
All models of CBC are similar except the selection of load cells and the program.
The main circuit board is the same as used in the CBW scales. Normally if a problem is
found with a circuit board the most cost effective method of solving the problem is to replace
the circuit board.
Schematics are attached in order to complete the documentation. However it is rare that the
problem due to a faulty component on the PCB is traced by a user.
The main PCB assembly includes:
A/D converter (AU1),
Microprocessor (DU1) and
Power supply/battery charger circuits (DU5, T2).

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5.0 CBC PARAMETERS AND CALIBRATION (VER. 1.2- 2.02)
5.1 CBC PARAMETERS (VER. 1.2- 2.02)
To set the parameters it is necessary to enter a secure menu by entering a password number
when requested.
To enter the parameter menus press [Tare] once, during the initial counting of the display
after the power is turned on.
The “Weight” display will show "  " requesting the password number to be entered. The
default password is "  " but other numbers can be set using the parameter menus. Press
the [0] key four times.
Press the [Tare] key.
The Parameter menu has 6 functions that can be accessed using the [U. Wt./Units] key to
cycle through the choices. The “Weight” display will show the name of the functions. To
enter a function, press [Tare].
At any time press the [Zero] key to return to weighing.
Weight Display Description
 See the Calibration section for details.
 Sets the scale increment. Press the [U. Wt./Units] key to cycle
through the options (1,2,5,10). Press [Tare] to accept the selection.
 Displays the A/D counts. Press [Tare] to return to menu.
 Press the [U. Wt./Units] key to show the options. Select automatic
accumulation ( ) when the scale becomes stable, Manual
accumulation () or Continuous (), the user must press the
[M+] key to accumulate data.
 



 Press [U. Wt./Units] to show the options for the auto-
zero range.
The value can be set to 0.5d, 1d, 2d or 4d. This is normally set to 1d
but can be increased to force the scale to zero if it is likely to have
small amounts of material spilled on the platform while in use.
 Set a new password number. Display will show " "
Enter the new password number then press the [Tare] key.
Display will change to " ", Enter the password again and press
[Tare] again.
The display will show "" to show the new password has been
accepted.
Record the new password number in a secure place.
 This is used to set the speed at which the scale will run the ADC. The
settings are 7.5, 15, 30 and 60. The slowest setting is 7.5 and the
fastest is 60.

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5.2 CBC CALIBRATION (VER. 1.2- 2.02)
The CBC scales calibrate using metric weights and the CBCa scales use either metric or
pound weights, depending on the weighing unit in use before calibration.
The scales will display a value of the weight to be used for calibration. However, you can
enter a different value if desired.
When the parameter menu shows "  " press [Tare].
The display will show "  " requesting to remove all weights from the platform.
Press the [Tare] key to set the zero point.
It will then show the calibration weight suggested as a whole number, for example:
“” “” “”
Either put this weight on the platform after the stable symbol is on or enter the value desired
and then press [Tare]. The display will show:
"" “” “”
Place the weight on the platform and press [Tare] again.
At all times the scale should be stable before pressing the [Tare] key to accept a weight. The
stability indicator will turn on to show the value is stable.
CBCa scales will also have the lb or kg indicator on, to show the unit of the weight
requested. If the scale was in pounds before starting the calibration, the weights requested
will be in pound values or if the scale was weighing in kilograms then metric weights will be
requested.
When calibration is done the display will show the counting from 0 to 9 and then return to
normal operation.
If an error message “  ” or “  ” is displayed, then re-check the calibration and repeat
it, if necessary.

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Suggested Calibration weights for CBC Series:
CBC SERIES
Model # CBC 3 CBC 6 CBC 15 CBC 30 CBC 45
2000g 5000 g 10 kg 20 kg 30 kg
Suggested Calibration Weights for CBCa Series:
After calibration, the scale should be checked whether the calibration and linearity is correct.
If necessary repeat calibration, ensure that the scale is stable before accepting any weight.
6.0 FACTORY PARAMETERS (VERSION 1.1-1.8 TO 1.2- 2.02)
To set the factory parameters after fitting a new PCB or when corruption is evident it is
necessary to enter a secure menu. This is done by entering the factory password number
when requested.
To enter the factory parameter menus press the [Tare] key during the initial counting of the
display after power turned on. The Weight Display will show "   " requesting the
password number to be entered.
The factory password is "  " and will over ride any other password they may have been
programmed and possibly forgotten.
Press the "  " key four times. The display will show "  ", Press the [Tare] key.
The Factory Parameter menu has the same 6 functions as described previously that can be
accessed by using the [Unit Wt.]key ([Lb/kg] key on CBCa series) to scroll through and the
[Tare] key to enter.
7.0 TWO POINT FACTORY CALIBRATION
When the parameter menu shows "  " press the [Tare] key.
The display will then show "  " to request all weight be removed from the platform.
Press the [Tare] key to set the zero point.
The display will then show the first calibration weight needed. It will be one third of the scale
capacity.
CBCa SERIES
Model # CBC 6a CBC 12a CBC 35a CBC 65a CBC 100a
5 Ib / 2 kg 10 lb / 5 kg 30 lb / 10 kg 50 lb / 20kg 100 lb / 30 kg

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Place this weight on the scale and press the [Tare] key after the stable symbol is on.
The display will now show the second weight needed. This will be full capacity.
Place the weight on the platform and press the [Tare] key again after the stable symbol is on.
When the scale begins its start up procedure the weights can be removed and calibration is
complete.
Suggested Factory Calibration weights:
CBC SERIES
CBC 3 CBC 6 CBC 15 CBC 30 CBC 45
Weight 1 1000 g 2 kg 5 kg 10 kg 15 lb
Weight 2 3000 g 6 kg 15 kg 30 kg 45 kg
CBCa SERIES
CBC 6a CBC 12a CBC 35a CBC 65a CBC 100a
lb kg lb kg lb kg lb kg lb kg
Weight 1 2 lb 1000g 4 lb 2 kg 10 lb 5 kg 20 lb 10 kg 40 lb. 15 kg
Weight 2 6 lb 3000g 12lb 6 kg 30 lb 15 kg 60 lb 30 kg 100 lb 30 kg
8.0 LOAD CELL DAMAGE
The most common reason a scale fails is that the load cell has been damaged. The damage
can be from 2 primary causes. The first is physical damage due to an overload or an impact
from the side and the second is damage due to the environment, such as moisture, extreme
heat or a cut cable if the cables are exposed.
PRINCIPLE OF OPERATION
The stain gauge load cell is a method of measuring the amount of stress put onto a metal
structure due to a weight being supported by the structure. The stress is measured using 4
strain gauge sensors mounted in a particular way on the metal structure.
These 4 strain gauges are connected in such a way that they form a wheatstone bridge. See
figure below. In the simplest load cells there are only the 4 resistances of the strain gauges to
consider. Normally without a load on the load cell all the resistances are the same. However
when the load cell has a weight on it 2 of the strain gauges will be in compression (A and D)
and the resistance will decrease and 2 will be in tension (B and C) and their resistance will
increase.

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350 ohm
350 ohm
350ohm
350ohm
AB
CD
+E
-S
-E
+S
BALANCED BRIDGE
10 VOLT POWER
SUPPLY
Vout = O VOLTS,
BETWEEN +S AND -s
351ohm
349ohm
351ohm
349ohm
AB
CD
+E
-S
-E
+S
UNBALANCED BRIDGE
FULL CAPACITY LOAD
ON THE LOAD CELL
10 VOLT POWER
SUPPLY
Vout = 0.028 VOLTS (28mv),
BETWEEN +S AND -s
This will cause the bridge to become unbalanced. When the bridge has a voltage across it
from +E to -E then the signal output at +S and -S will show a voltage of zero volts with no load
and a small voltage proportional to the load as the load is increased. Typical load cells show
20-30mv of signal if the excitation voltage is 10volts and the load cell is fully loaded.
Most load cells used in scales are not as simple as this example. They have additional
resistance elements added to compensate for temperature variations and to set the outputs to
correct voltages. The circuit of a typical load cell is shown below.
A method to check the basic function and integrity of a load cell can be done using an
ohmmeter and voltmeter with up to a 10volt power supply.

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Before the load cell is connected to the power supply use the ohmmeter to measure the
resistance between the wires. Typical resistance values are:
+E to -E 410 ohms ±30 ohms
+S to -S 350 ohms ± 2 ohms
+E to +S or any other combination similar approximately 270 ohms.
If the load cell has Sense connections in addition they are connected to the excitation internal
to the load cell.
Connect the load cell +E and -E to a power supply, typically 10 volts. Never use more than
12 volts as it may damage the load cell. Measure the voltage between +S and -S.
With no load the voltage should be approximate 0mv ±3mv.
With a mass on the load cell the output voltage should increase. The amount of increase will
depend upon the sensitivity of the load cell, capacity of the load cell, the excitation voltage
and the amount of mass placed on the load cell. Most load cells have a sensitivity of either
2mv/V or 3mv/V.
The expected change to the output is:
Vout = (2mv/V) * Vext * Mass
capacity of load cell
For example a 2mv/V load cell of 30Kg capacity with 20Kg placed on it. Vext is 5 volts would
give a output of approximately:
Vout = (2mv/V) * Vext * Mass = 2mv/V * 5V * 20Kg = 6.7mv
capacity of load cell 30kg
If the load cell has been damaged the no load voltage will likely be greater than 3mv or the
loaded voltage will be grossly different from the expected value. Remember the loaded
voltage will be offset by the amount of zero load voltage measured.
The load cell can be tested while it is connected to the A/D converter circuit board, using the
scale power supply for excitation voltage.
TESTING LOAD CELLS IN THE SCALE
The signal from the load cells is amplified by the circuits on the A/D circuit board.
The signal needs to be amplified to make it acceptable for the A/D converter used. The
CBC/CBW scales amplify the input by 200, and change the no load voltage to about +2.5V.
The amplified and offset voltage is measured at pin 6 of IC7, the INA118P amplifier IC. This
voltage is sent to the filter and then to the A/D converter.

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9.0 CBC RS-232 INTERFACE
The addition of the RS-232 for these scales requires the following:
Scale
Lead with 9pin d-subminiature converter
Cover with RS-232 Connector Hole cut out.
Main PCB with RS-232 parts included
The scale will have a PCB for the main parts of the electronics. These boards do not have
any parts for the RS-232 interface included. Replace the main PCB with the new one which
has the RS-232 interface included. Fit the CPU and the jumpers -taken from the earlier PCB
into the new PCB.
All parameters and Calibration including the Two Point Factory Calibration must be set before
the new PCB will be put to use for weighing.
The 3 pin connector from the RS-232 connecter goes to the main PCB. The 25 pin d-
subminiature connector is attached inside the case using the 2 hex standoffs that come with
the connector with lock-washers and nuts.
There is no special configuration or software that needs to be enabled for the interface to
operate. The manual already has all the details for the RS-232 interface in it.
INSTALLING THE RS-232 IN CBC SCALES
•Remove the top pan and take out the
5 screws from the bottom of the scale.
2.
•Detach the 4 cables connected with the
Load-cell, Display, Power Switch and
Battery Chamber from the main PCB.

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•Remove the main PCB by taking out
the 4 screws from the 4 corners.
•Install a new main PCB which has
the RS-232 hardware already fitted
into it.
•Plug in the RS-232 interface cable
into the connector marked “SER”.
•Take-out the blanking label from the
window provided on the right side of
the scale.
•Fix the 9-pin D-subminiature connector in the cut-out of the window and secure it with
the special screws provided.
•Remove the Microprocessor from the earlier PCB and also if the link between K1 and
K5, if any. Install the micro-processor and the links in the same way as it was in the
old board into the new board. Be very careful not to bend the legs while removing the
micro-processor.
•Plug the cables coming from the Load-cell, Display, Battery and Power Switch into
the main PCB.
•Turn the scale on to check whether the scale is working. Note that without the pan
installed the scale may not show zero.
•Replace the cover back and secure it with all 5 screws.
•Place the stainless steel pan back on the scale.
•Switch the scale on to verify proper installation.
•Set the parameters as described in the Service Manual and perform the Factory
Calibration by using Pin 9999.
•If the RS-232 needs to be disabled or configured, follow the procedure for parameter
settings as given in the manual.

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10.0 SCHEMATICS
The following schematics are included as a guide for the experienced Service Technician. If
you are not experienced we do not advice you to change parts on the circuit boards or
otherwise disturb the electronics.
If you require assistance please contact your dealer or Adam Equipment. We will be happy to
help you resolve problems or determine the cause of a problem if you send us a full
description of the scale and the problem.
The following schematics are included:
CBC Main PCB assembly, pages 2

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@Adam Equipment Company 2005
Manufacturer’s Declaration of Conformity
This product has been manufactured in accordance with the harmonised European
standards, following the provisions of the below stated directives:
Electro Magnetic Compatibility Directive 89/336/EEC
Low Voltage Directive 73/23/EEC
Adam Equipment Co. Ltd.
Bond Avenue
Denbigh East Estate
Milton Keynes, MK1 1SW
United Kingdom
FCC COMPLIANCE
This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a commercial environment. The
equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in
accordance with th
e instruction manual, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause harmful interference in which case
the user will be required to correct the interference at his own expense.
Shielded interconnect cables must be employed with this equipment to insure compliance with the
pertinent RF emission limits governing this device.
Changes or modifications not expressly approved by Adam Equipment could void the user's authority
to operate the equipment.

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ADAM EQUIPMENT is an ISO 9001:2000 certified global organisation with more than 30
years experience in the production and sale of electronic weighing equipments. Products are
sold through a world wide distributor network -supported from our company locations in the
UK, USA and SOUTH AFRICA. The company and their distributors offer a full range of
Technical Services such as on site and workshop repair, preventative maintenance and
calibration facilities.
ADAM’s products are predominantly designed for the Laboratory, Educational, Medical and
Industrial Segments. The product range can be classified as follows:
−Analytical and Precision Laboratory Balances
−Top Loading Balances for Educational establishments
−Counting Scales for Industrial and Warehouse applications
−Digital Weighing/Check-weighing Scales
−High performance Platform Scales with extensive software
features including parts counting, percent weighing etc.
−Digital Electronic Scales for Medical use
−Retail Scales for price computing
Adam Equipment Co. Ltd.
Bond Avenue
Milton Keynes
MK1 1SW
UK
Phone:[phone]
Fax: [phone]
e-mail:
[e-mail]
Adam Equipment Inc.
26, Commerce Drive
Danbury, CT
06810
USA
Phone: [phone]
Fax: [phone]
e-mail:
[e-mail]
Adam Equipment S.A. (Pty) Ltd.
P.O. Box 1422
Kempton Park 1620
Johannesburg
Republic of South Africa
Phone [phone]
Fax: [phone]
e-mail:
[e-mail]
© Copyright by Adam Equipment Co. Ltd. All rights reserved. No part of this publication may
be reprinted or translated in any form or by any means without the prior permission of Adam
Equipment.
Adam Equipment reserves the right to make changes to the technology, features,
specifications and design of the equipment without notice.
All information contained within this publication was to the best of our knowledge timely,
complete and accurate when issued. However, we are not responsible for misimpressions
which may result form the reading of this material.
The latest version of this publication can be found on our Website.
Visit us at www.adamequipment.com