Citizen CTB-150 User manual

!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"#$%&'()*%!+#,&-('.!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!/!0$)%1!2%,#$!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!340!2$'*$5!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!

CTB serial bench scale service manual
II
UGCTB-E1.0
Table of Contents
SECTION 1 INTRODUCTION…………………………………………………………1
SECTION 2 SPECIFICATIONS……………………………………………………..…2
SECTION 3 INSTALLATION……………………………………………………………3
SECTION 4 KEY DESCRIPTIONS……………………………………………………4
SECTION 5 DISPLAYS…………………………………………………………………5
SECTION 6 OPERATION…………………….……………………………………….…6
6.1 Zeroing the display………………………………………………………………….6
6.2 Taring……………………………………………………………………………..……6
6.3 Weighing a sample…….………………………………………………….………….6
6.4 Parts counting…………………………………………………………………………6
6.5 Check-weighing…………………………………………………………………….7
6.6 Accumulated total……………………………………………………………………8
6.7 Net/gross change …………………………………………………………………….8
SECTION 7 PARAMETERS…………………………………………………………9
SECTION 8 BATTERY OPERATION………………………………………………..…11
SECTION 9 RS-232 OUTPUT………………………………………………………….12
SECTION 10 CALIBRATION……………………………………………………..…….13
SECTION 11 TECHNICAL PARAMETES…………………………………………….14
SECTION 12 TROUBLE SELFCHECKING…………………………..…….……... 15
SECTION 13 TROUBLESHOOTING………………………………….………………16
13.1 No power………………………………………………….…………….…………. 16
13.2 No display…………………………………………………………..………..……. 17
13.3 Can’t charge the battery…………………………………………..………………18
13.4 Can’t weighing……………………………………………………………………. .19
13.5 Reading jump……………………………………………………………..………..20
13.6 Keyboard can’t work……………………………………………………………….20

CTB serial bench scale service manual
III
SECTION14 CHANGE PARTS PROCESS…………………………………………...21
14.1 Replace main board……………………………………………………….……....21
14.2 Replace load cell……………………………………………………..……………21
14.3 Replace MPU…………………………………………….………………………...22
14.4 Replace battery………………………………………………….…………………22
SECTION15APPENDIX…………………….………………………………………..…23
15.1 Schematic (main)…………………………………………………………….….…23
15.2 Schematic (display)………………………………………..………….……..……24
15.3 Parts drawing…………………………………………….…………..…….……...25
15.4 Parts list…………………………………………………….……………….……...26
15.5 Error codes…………………………………………………………………………27
15.6 Numeric and alphabetic characters displayed on LCD……………….……….27

CTB serial bench scale service manual
1
SECTION 1 INTRODUCTION
The CTB series of bench scale provides an accurate, fast and versatile series of
general purpose weighing scale with counting and check-weighing functions.
There are 3 series scales within the range, the platform size from 420mm x 520mm ,
the capacity range from 150lb to 600lb.
All the keypads are sealed, color coded membrane switches and the displays are
large easy to read liquid crystal type displays (LCD). The LCD’s are supplied with a
backlight.
All units include automatic zero tracking, audible alarm for pre-set weights, automatic
tare, and an accumulation facility that allows the individual weights to be stored and
recalled as an accumulated total.

CTB serial bench scale service manual
2
SECTION 2 SPECIFICATIONS
Model CTB-150 CTB-300 CTB-600
Platform size 420mm x 520mm 420mm x 520mm 420mm x520mm
Capacity 150lb 300lb 600lb
Resolution 1:3000
Interface RS-232 Output Optional (standby)
Stabilisation Time
1 Seconds typical
Operating
Temperature 5°C - 35°C / 41°F - 95°F
Power supply External AC adapter, 9V 800mA
Calibration Automatic External
Display 6 digits LCD digital display with 24mm high digits
Balance Housing Indicator ABS Plastic
Load cell drive
voltage Max 5V/150mA
Load cells Up to four 350 ohms cells

CTB serial bench scale service manual
3
SECTION 3 INSTALLATION
GENERAL INSTALLATION
The scales should be sited in a location that will not degrade the accuracy.
Avoid extremes of temperature. Do not place in direct sunlight or near air conditioning
vents.
Avoid unsuitable tables. The tables or floor must be rigid and not vibrate. Do not
place near vibrating machinery.
Avoid unstable power sources. Do not use near large users of electricity such as
welding equipment or large motors.
Avoid high humidity that might cause condensation. Avoid direct contact with water.
Do not spray or immerse the scales in water.
Avoid air movement such as from fans or opening doors. Do not place near open
windows.
Keep the scales clean.
Do not stack material on the scales when they are not in use.
INSTALLATION OF CTB SERIES
The pillar is attached to the base using a bracket that must first be attached to the
base frame using the 4 bolts supplied. The Pillar is secured to the bracket using 2
set screws. The cable from the base to the indicator module is run through the tube,
out through the plastic support at the top. Excess cable can be stored within the
tube.
The CTB Series comes with a stainless steel platform packed separately. Place the
platform in the base.
Level the scale by adjusting the four feet. The scale should be adjusted such that the
bubble in the spirit level is in the centre of the level and the scale is supported by all
four feet. If the scale rocks readjust the feet.
Attach the indicator module to the pillar by sliding it over the bracket with the flanges
engaged in the groves on the base.
Attach the AC power adapter to the connector on the back of the indicator.

CTB serial bench scale service manual
4
SECTION 4 KEY DESCRIPTIONS
Zero or
Set the zero point for all subsequent weighing. The display shows zero.
A secondary function , of "Enter" key when setting parameters or other functions.
Tare or
Tares the scale. Stores the current weight in memory as a tare value, subtracts the
tare value from the weight and shows the results. This is the net weight. Entering a
value using the keypad will store that value as the tare value.
A secondary function +, of incrementing the active digit when setting a value for
parameters or other functions.
Smpl or
Enter counting mode from weighing mode. Shift unit weight, counts and total weight
when counting mode. Move the active digit right when setting values for other
functions.
The second function, when the scale self-check press the key, it will show ”CAL X”, it
is an arithmometer (COUNTER) for the times of calibration is successful.
N/G
Used to select the weight model of the scale. If the scale has tared, switch to the
mode of net weight or gross weight. Move the active digit left when setting values for
other functions.
The second function, when the scale self-check press the key, it will show “opt X”, it
is an arithmometer (COUNTER) for the times of parameter setting.
Func or F
Used to select the function of the scale. If the scale is weighing it will select parts
counting. Of it is not in weighing mode it will return the user to weighing.
Secondary function ( C ) , is to act as a clear key when setting values for parameters
or other functions.
Print or
To print the results to a PC or printer using the optional RS-232 interface. It also
adds the value to the accumulation memory if the accumulation function is not
automatic.
Secondary function (ESC) , is to return to normal operation when the scale is in a
parameter setting mode.
ON/ OFF or
Turn on or off the power.

CTB serial bench scale service manual
5
SECTION 5 DISPLAYS
The LCD display will show a value and a unit to the right of the digits.
In addition there are labels for TARE, GROSS weight, Zero and for Low battery
Center of Zero Indication
OK
HI
LO
GROSS
TARE
ZERO
/pcs
lb
Checkweighing Symbols
Stability Symbol
Low Battery Symbol
Parts Counting Units
Weighing Units

CTB serial bench scale service manual
6
SECTION 6 OPERATION
6.1 Zeroing The Display
You can press the ZERO/ENTER key at any time to set the zero point from which all
other weighing and counting is measured, within set % in 0-Range parameter from
power up zero. This will usually only be necessary when the platform is empty.
When the zero point is within “CENTRE OF ZERO” range display will show the
indicator for “zero”.
The scale has an automatic rezeroing function to account for minor drifting or
accumulation of material on the platform. However you may need to press the
ZERO/ENTER key to rezero the scale if small amounts of weight are shown when the
platform is empty.
6.2 Taring
Zero the scale by pressing the ZERO/ENTER key if necessary.
Place a container on the platform, a value for its weight will be displayed.
Press the TARE key to tare the scale. The weight that was displayed is stored as the
tare value and that value is subtracted from the display, leaving zero on the display.
The "TARE" indicator will be on. As product is added only the weight of the product
will be shown. The scale could be tared a second time if another type of product was
to be added to the first one. Again only the weight that is added after taring will be
displayed.
When the container is removed a negative value will be shown. If the scale was tared
just before removing the container this value is the gross weight of the container plus
all product that was removed. The zero indicator will also be on because the platform
is back to the same condition of “CENTER OF ZERO” range.
6.3 Weighing a sample
To determine the weight of a sample first tare the empty container then place the
sample in the container. the display will show the weight and the units of weight
currently in use.
6.4 Parts Counting
When the scale is showing weight, pressing the SMPL key will start the parts
counting function.

CTB serial bench scale service manual
7
Before beginning, tare the weight of any container that will be used, leaving the
empty container on the scale. Place the number of samples on the scale. The
number should match the options for parts counting, 10, 20, 50, 100 or 200 pieces.
Press the SMPL key to begin. The scale will show "SP 10" asking for a sample
size of 10 parts. Change the sample size by pressing the TARE/!key. the display
will cycle through the options: 10,20, 50, 100, 200 and back to 10.
Press the SMPL key when the number matches the number of parts used for the
sample. As more weight is added the display will show the number of parts (pcs).
Press the FUNC key to return to normal weighing.
6.5 Check-Weighing
6.5.1 About check-weighing
Check-weighing is a procedure to cause an alarm to sound when the weight on the
scale meets or exceeds values stored in memory. The memory holds values for a
high limit and a low limit.
Check range:
set hi-limit and low-limit as different value, also hi-limit value is larger than low-limit.
Check key point:
set hi-limit and low-limit as same value.
Check mode 2:
When check range, the display will show OK and the beeper will sound when the
weight is between the limits.
When check key point, the display will show Ok and the beeper will sound when the
weight is under the limits.
Check mode 3:
When check range, the display will show OK and the beeper will sound when the
weight is out of the limits.
When check key point, the display will show Ok and the beeper will sound when the
weight is over the limits.
6.5.2 Set limits
Press F key, it will display “F0 H-L”, press ZERO key to enter, use TARE key to
select “SET HI” or “SET LO”, press ZERO key to enter, use SMPL key to move
active digit, use TARE key to change value, use F key to clear value. After you enter
the value, press ZERO key to sure, press Print/M+ key to escape.

CTB serial bench scale service manual
8
6.5.3 Set check weighing mode
Press F key to enter setting mode, press TARE until display show “F4 OFF”, press
ZERO key to enter, press TARE key until display show “BEEP”, press ZERO key to
enter, press TARE key to select BP 2(check mode 2), BP3 (check mode 3), BP1(not
sound), press ZERO key to sure, press PRINT/M+ key to escape.
6.5.4 NOTE
The weight must be greater than 20 scale divisions for the check weighing to operate.
To disable the Check-Weighing function enter zero into both limits by pressing the
FUNC key when the current limits are shown then pressing ZERO/ENTER to store
the zero values.
6.6 Accumulated Total
The scale can be set to accumulate manually by pressing the PRINT key. See the
PARAMETERS Section for details of selecting the method using function "F5 P RT".
The accumulation function is only available when weighing. It is disabled during
parts counting.
The weight displayed will be stored in memory when the PRINT key is pressed and
the weight is stable.
The display will show "ACC 1" and then the total in memory for 2 seconds before
returning to normal. If the optional RS-232 interface is installed the weight will be
output to a printer or PC( this type machine has no print function).
Remove the weight, allowing the scale to return to zero and put a second weight on.
Press the PRINT key, the display will show "ACC 2" and then the new total.
Continue until all weights have been added.
To view the totals in memory press enter the PARAMETER SECTION and use
function "F1 TOL". See below.
6.7 Net/gross change
When you weigh, press N/G key , you can check net weight and gross weight.

CTB serial bench scale service manual
9
SECTION 7 PARAMETERS
The scale has 6 parameters that can be set by the user plus a method of entering the
calibration section.
To set parameters press the FUNC key.
The display will show the first function, "F0 H-L".
Pressing the TARE/+ will cycle through the other functions.
Pressing ZERO/ENTER will allow you to set the function. It may be necessary to
either use TARE/+ or set a value using the SMPL/"key to move the active digit and
then using the TARE/!key to increment a digit, followed by the ZERO/ENTER key
to enter the value. Use the PRINT/ESC key to leave a parameter unchanged.
For example when the display shows “F0 H-L” press the ZERO/ENTER key to
begin.
The display will show “Set Lo”, press the ZERO/ENTER key to set the low limit, or
press the TARE/+ to skip to the next parameter, “Set Hi” for setting the high limit.
After pressing the ZERO/ENTER key to set a limit, use the the SMPL"keys to
change the flashing digit, then use the TARE/!key to increment the flashing digit.
Continue to the next digit and set it as needed.
When all digits have been set press the ZERO/ENTER key to store the value. The
display will go back to the parameter just set, i.e. “Set Lo”. Advance to another
parameter if needed or press the PRINT/ESC key to return to weighing.

CTB serial bench scale service manual
10
FUNCTION MENU SETTINGS
FUNCTION
SUB-FUNCTION DESCRIPTION DEFAULT
VALUE
SEt Lo Set a value for the Low limit. 000.000 F0 H-L
SEt HI Set a value for the High Limit. 000.000
to CLr Clears the accumulation memory
without printing the results.
to P-C Prints the Accumulation memory
total and then clears the memory.
F1 toL
to Prt Prints the Accumulation Total, does
not clear the memory.
bL Set the backlight to be on,
automatic or off,
EL on
EL Au
EL off
EL Au
beep Set the beep mode.(check weighing
mode 2, check weighing mode3, no
beep)
F2 off
sleep Set the time of automatic sleep:
1,5,10,30 or OFF
10
Prog Pin Enter the programming and
calibration menus by entering the
correct password. See the section
11.

CTB serial bench scale service manual
11
SECTION 8 BATTERY OPERATION
The weighing indicator can be operated from the battery if desired. The battery life is
approximately 100 hours.
When the battery needs charging a symbol on the weight display will turn on. The
battery should be charged when the symbol is on. The scale will still operate for
about 10 hours after which it will automatically switch off to protect the battery.
To charge the battery simply plug into the mains power. The scale does not need to
be turned on.
The battery should be charged for 12 hours for full capacity.
Just under the quantity display is an LED to indicate the status of battery charging.
When the scale is plugged into the mains power the internal battery will be charged.
If the LED is green the battery has a full charge. If it is Red the battery is nearly
discharged and yellow indicates the battery is being charged.
As the battery is used it may fail to hold a full charge. If the battery life becomes
unacceptable then contact your distributor.

CTB serial bench scale service manual
12
SECTION 9 RS-232 OUTPUT (opt ional)
The CTB Series of scales can be ordered with an optional RS-232 output.
Specifications:
RS-232 output of weighing data
ASCII code
8 data bits
No Parity
Connector: 25 pin d-subminiature socket
Pin 2: Output
Pin 3: Input, not used at this time
Pin 5: Signal Ground
Data Format for normal weighing operations, parts counting or recalling of totals from
memory will all be different. Examples follow:
Normal Output
When parts counting the weight, unit weight and count will be printed.
When recalling the Total weight stored in the accumulation memory the output format
is:
GS 12.340kg GS for Gross weight, NT for net weight and a unit of weight
No.. 1 This number increments every time a new value is
stored in memory
Total 12.340kg The total value stored in memory
<lf> Includes 2 line feeds
<lf>
*************** A line of stars is shown
<lf> Includes 1 line feed
TOTAL
No. 5
Wgt 21.455kg .
***************
GS 12.340kg GS for Gross weight, NT for net weight and a unit of weight
U.W. 123.4g/pcs The average piece weight computed by the scale
PCS 100pcs The number of parts counted
<lf> Includes 2 line feeds
<lf>

CTB serial bench scale service manual
13
SECTION 10 CALIBRATION
Turn the power off. During the counting from 9 to 0 press the FUNC/C key.
The display will show "CAL " for a few seconds. While it is showing "CAL " press
the UINT , PRINT and TARE keys in sequence to enter the Calibration section.
The display will show "unLoAd".
Remove any weight from the platform. Press the ZERO/ENTER key.
The display will show "LoAd". Place the calibration weight on the scale. Press the
ZERO/ENTER key.
If the calibration weight is right, the display will show “PASS”, If the calibration weight
is unapt, the display will show “FAIL H” or “FAIL L”. the calibration is not
acceptable.
If the calibration is acceptable the display will return to normal. If an error message is
shown try calibration again as a disturbance may have prevented a successful
calibration.
If the problem persists then contact your dealer.
SECTION 11 TECHNICAL PARAMETERS
Press F key when normal weighing mode, display shows “F0 H-L”, press TARE key
until display shows “P ROG”, press ZERO key, display shows “PIN”, You can press
unit PRINT TARE key to enter setting mode, press Tare key to select parameter,
press Zero key to sure, press Print key to escape. Before you set parameters, please
short the K1.
FUNCTION
SUB-FUNCTION DESCRIPTION

CTB serial bench scale service manual
14
AZN 0 This option is used to select the auto zero
tracking.
Options : 0.25d, 0.5d,
0-AUTO This option is used to select the Initial zero
setting range (mechanism) when turn the
indicator.
Options : 0%, 2%, 5%, 10%, 20%
P1 REF
0- RANGE This option is used to select the (SAZSM)
manual zero range when press the ZERO key.
Options: 2%, 4%, 10%, 20%,
C AP
This display will show xxxxxx for setting the
capacity.
CAL Calibrate, see detail in section 10.
P 2 CAL
CNT This display will show xxxxxx for indicating the
internal counts.
P-AUTO Automatic print setting, when the weight is
stable, the data will be printed automatic
P-PRT Manual print setting, when the weight is stable,
press the PRINT key, the data will be printed.
P3 P RT
P cont Connect PC, the data will be send to PC
AUDIT TRAIL COUNTER :
CALIBRATION:
When the scale self-check press the SMPL/ key, it will show ”CAL X”, it is an Audit
trail counter for each Successful CALIBRATION.
PARAMETER (OPERATIONAL) COUNTER :
When the scale self-check press the N/G key, it will show “opt X”, it is Audit trail
counter for any change in parameter setting.
SECTIOIN 12 TROUBLE SELF CHECKING
Problem Possible cause Common solutions
Display is
blank, No
turn on test
Mains power is turned off
Power supply not plugged in
Power supply faulty
Internal battery not charged
Display turned off
Check power is going to the
scale and switch is on.
Verify the voltage going to the
scale matches the power supply
labels on the power module or
scale.

CTB serial bench scale service manual
15
Display
blank
after turn on
test,
Error
message
Display is
locked
Pan not installed
Unstable weight
Load cell damaged
Mechanics damaged
Check the pans are installed
correctly.
Try turning the scale on again.
OL or FULL
appears on
display
Maximum capacity exceeded
Load Cell or mechanics
damaged
Power supply faulty
Check the pans are installed
correctly.
Try turning the scale on again.
UL or NULL
displayed
Weight on scale below
permissible limit
Pan has been removed
Pan support not seated properly
Power supply faulty
Load Cell or mechanics
damaged
Check the pans are installed
correctly.
Try pressing Zero key.
Try turning the scale on again.
Display is
unstable
Drafts or air currents
Obstruction under pan
Sample is moving (animal
weighing)
Vibrations through table
Temperature changed
dramatically
Power supply faulty
Verify the scale is in a
acceptable location and on a
good table.
Verify the power supply is
correct for the scale.
Weight
value
incorrect
Calibration error, Recalibrate
Linearity error, set Linearity
Unit calibrated with inaccurate
weight
Balance not level
Obstruction between sample and
cover
Wrong unit of weight displayed
Calibrate again, paying special
attention to the mass used, the
stability of the scale, and the
weighing units required.
If linearity can be set by the user
it will be described in the user
manual.
Check pan is installed correctly.
Verify installation is acceptable.
Cannot use
Full
Capacity
Over load Stops hitting pan
support or hitting bottom of load
cell
Shipping screw not removed if
applicable
Electronic problem on A/D
Parameters set incorrectly
Load Cell or mechanics
Damaged
Look for obstruction under pan,
shipping screws, and verify pan
installation.
Check the weighing units used.
Not Linear
Overload stops hitting too soon
Load cell or mechanics damaged
A/D damaged
Look for obstruction under pan,
shipping screws, and verify pan
installation.
If linearity can be set by the user
it will be described in the user
manual.
Off Center Adjust mechanics
Overload Stops not correct
Look for obstruction under pan,
shipping screws, and verify pan

CTB serial bench scale service manual
16
Loading
error
Overload Stops not correct
Load Cell damaged
shipping screws, and verify pan
installation.
Battery will
not
charge
Mains voltage not present or too
low
Charging circuit failure
Battery Failure
Verify the batteries are
rechargeable types.
Check power supply voltage is
correct.
SECTIOIN 13 TROUBLESHOOTING
13 2no display
START
T10
pin
3
output
5V
CHK T10 and around circuit
Battery
voltage>5
.5
V
Charging the battery
immediately
or replace the battery
CHK
U1
pin
9
High level when power
on
And return to
low level
CHK power
switch
and connector
Replace power switch or
CHK ST and around
circuit
CHK U1 and around circuit
CHK ST
(11.0592MHz)
CHK U1 and around circuit
START
CHK LCD
break?
Replace
LCD

CTB serial bench scale service manual
17
13 3 Can’t charge the battery
START
Battery bad?
(battery
Replace battery
Fuse open?
Replace the fuse and solve
the problem (like
transformer bad)
Cut the circuit,
then CHK
transformer
output >
10V
Replace
transformer
Open
U5
pin11/12,
CHK BR1
output
>12V
CHK BR and around
circuit
Restore the circuit,
CHK U5 pin2
output>7V
CHK M/B U5 and around
circuit
CHK M/B D1, R7 and around circuit
N
Y