Seca 703 CN User manual

for seca 703 / 704 CN
Service Manual
7031021999
7031321009
7031321999
7047021009
7047021099
7047021159
7047021244
7047021249
calibratable scale based on a DMS platform - load cell
703 : Columnscale kg, lbs, sts digital, battery connection, optional with measuring
rod.
704 : Columnscale calibrated kg, Battery connection
Valid as of: 01.12.2010
Variants:
Content:
Function diagram 25-01-02-584
Description DMS module 30-34-00-645 b
Description display module 30-34-00-618 a
Cabelplan 08-02-06-032 a
Cableplan 08-02-06-035 a
Description of faults 30-34-00-588 c
Calibration (lin.) 30-34-00-603
Replacement 30-34-00-720
PC configuration program 30-34-00-672 b
Spare parts Display 30-34-00-717 b
Spare parts baseframe 30-34-00-719 c
Description:
Service Manual Number
17-05-01-325-d
Spare parts baseframe Mod. 703 DMS high end 30-34-00-736 b
Manual number: 17-05-01-325-d

Service manual Description of the electronics
05.08.03 /Jensen / Rei 34-34-00-645 b
1
Brief description of the DMS module
Introduction
The DMS modules are used to determine weights using a load cell with strain gauges. The DMS low
end module also accommodates the display and the operating unit. To allow the modules to be
adapted to different scales, an EEPROM is integrated which is used to configure the module. A
connection to the SeSAM bus (Seca’s Serial Autoconfiguring Multicontroller bus) is provided via which
the scale can be calibrated and additional modules can be connected.
Load cell A/D Converter
Temperature
measurement
Voltage
measurement
µC
Voltage
control
Voltage
control
EEPROM
Quartz
SeSAM Bus
Power On
Reset
Mains connection
Battery/rechargeable
batteries
Display
I0000
.
Operation
Weight measurement
The DMS modules use load cells with strain gauges in a double bridge circuit as sensors.
The entire analog part runs on its own supply voltage. This voltage can be switched by the µC to 3V,
5V or 10V. This voltage is also supplied to the load cells. At full load, they deliver a bridge output
voltage of 2mV/V.
This voltage is measured by a dual slope a/d converter. The DMS ext module can evaluate up to four
load cells which are multiplexed accordingly. Only one load cell can be connected to the other types of
DMS modules.
The conversion time is selected so that a new measured value is available every 0.1 s.
The resolution of the a/d converter is 0.05 µV/V. If several load cells are connected, keep in mind that
the resolution relates to the mean output signal of all the load cells connected.
When these measured values are within the expected range, they are converted into a weight value
using a third order polynomial. In order to increase accuracy, eight measured values are used to
calculate the weight to be displayed.
The first value obtained after switch-on is used as the zero point. If the values obtained later on do not
deviate strongly from this value, the zero point is corrected in order to compensate for possible drifts.
(Please also refer to temperature measurement.)

Service manual Description of the electronics
05.08.03 /Jensen / Rei 34-34-00-645 b
2
Display (only DMS low-end module and SLC highend)
Whenever eight new measured values are available, i.e. approx. every 0.8 s, the weight is displayed.
The display is an LCD which is controlled by duplex operation. A maximum of five digits as well as a
few special characters can be displayed.
Explanation of the special characters:
•The battery symbol is used to alert of the fact that the battery is going flat.
•Hold indicates that the weight display has frozen.
•Tare or Net indicate that a weight on the scale has been tared off.
•The left arrow indicates if additional explanations are given next to the display.
•The weight units on the right show the unit in which the measured weight is displayed.
Temperature measurement
In order to compensate for the load cell’s temperature drift, the temperature is measured regularly and
the measured value is adjusted accordingly.
To perform this measurement, a capacitor is charged every 2 seconds alternately via a reference
resistor and an NTC with a linearization resistor connected in parallel. The time until the capacitor has
reached a specific voltage is measured. The temperature is calculated from the ratio of the two times.
To reduce measured value fluctuations, a mean value of 16 temperature values is always formed. The
fluctuation then amounts to approx ±0.2°C.
The difference between the current temperature and the temperature measured when the last zero
point was obtained is used to determine a projected zero point. To do so, one assumes that the weight
change per °C is constant. The weight value is then corrected in accordance with the zero point
calculated and in accordance with the difference to the temperature measured when the scale was
calibrated. A linear and a square term are used for this purpose.
Power supply
Power supply is provided by AA size batteries (batteries or rechargeable batteries) and a plug-in power
supply unit. The batteries pass the voltage via reverse voltage protection diodes to a 3V in-phase
regulator. A coil which suppresses interference and a buffer capacitor come next. This 3 V supply
voltage is supplied to the digital part of the circuit.
Another in-phase regulator generates the voltage for the analog part. The µC can set this regulator to
3V, 5V or 10V.
In order to operate the module on rechargeable batteries a recharging circuit can be connected. This
circuit charges the rechargeable batteries at a constant current when a power supply unit is connected.
When the supply voltage is applied, a power-on reset is initiated at the µC via an RC element.
To monitor the condition of the batteries, their voltage is measured every 2s. For this purpose, a 2.2 V
reference voltage is integrated upwards and the time until the voltage has reached approx. 9% of the
supply voltage is measured. Afterwards, a downwards integration is made from 2.2V to the threshold.
From these two results, a measured value for the voltage is calculated. If the voltage drops below a
certain limit, the user is alerted by the battery symbol in the LCD. If the next threshold is undershot,
„bAtt“ is displayed and weighing is no longer possible.
Operation (only DMS low-end module and SLC highend, with the exception of
vibration-sensitive switch and platform switch)
Four buttons are provided; one is used to switch the module on and off, the others can be programmed
as required. These three buttons can be pressed just lightly or longer (longer than 1.5s), so that six
events are available. The actions tare, hold and unit switch-over can be assigned to them.
If you press another button when switching on the scale, the scale will switch to the calibration counter
and recalibration mode.
Instead of the normal start button a piezo diaphragm can be soldered to the PI connection. If the piezo
diaphragm registers a vibration, a transistor switches and generates an interrupt signal which causes
the µC to start.

Service manual Description of the electronics
05.08.03 /Jensen / Rei 34-34-00-645 b
3
If the start button is directly connected to this interrupt input, a button is obtained which is only active
when the scale is switched off. It can be fitted under the platform, for instance, so that the scale is
started by briefly stepping on it.
Programming
The DMS modules are equipped with an EEPROM which is controlled via the I²C bus protocol. On this
EEPROM all parameters are stored that can be used to influence the program sequence. For example
the way the weight is displayed or the allocation of buttons. It also stores the coefficients for
determining the weight and data for temperature compensation, e.g. the factors for the polynomial.
Furthermore, the scale can store values to be retrieved when the scale is switched on the next time,
e.g. the weight unit used last.
In order to avoid errors, the EEPROM contents are divided into blocks which are monitored by cyclic
redundancy checks. The hamming distance is 4 so that single errors can be corrected and double
errors are certainly detected. In addition, values which are recalculated when the scale is in operation
can be replaced by default values if an error is detected that cannot be remedied.
Serial bus
To allow the scale to be calibrated and additional modules, such as additional displays, to be
connected, the DMS modules are equipped with an interface to the SeSAM bus.
On this bus the stabilized and non-stabilized supply voltages are available. Via a data and a clock
pulse line all relevant data is transmitted to other modules. A special start line is provided via which the
scale can be switched on or other modules can signal that they want to send data.
Both data and start line are open collectors so that they can be switched to low by all modules.
For further details on the bus, please refer to the relevant documentation.
Fault handling
If faults occur, the SeSAM bus initiates a fault message with the relevant fault code. Furthermore, each
fault message includes the number of the module type on which the fault has occurred and a code
which indicates how long the message is to stay on display and which displays are to be suppressed.
The DMS low end module displays its own fault messages on its LCD. Module type (0 for the low-end
module) and fault number are displayed. The other DMS modules only transfer fault messages to the
bus (module type = 1).
The following fault messages are implemented:
10 20 bit counter overflow
11 Counts out off range
12 Switch-on zero setting out off range
13 Zero tracking out off range
14 Error in the kg value calculation
15 Recalibration error
bAtt Battery voltage too low
21 Error in battery voltage measurement
22 Error in temperature measurement
tEMP Temperature range exceeded ( < 0°C or > 50°C)
30 General bus error
32 Command buffer full
33 More than 8 slaves detected
40 EEPROM error
41 Incorrect EEPROM access
50 Rom checksum error
51 Menu error
CArd Invalid Chipcard
OFF Chipcard has scale not released
6x Error in measurement of lenght
Notice : Chipcard is saving now

Service manual Description of the electronics
05.08.03 /Jensen / Rei 34-34-00-645 b
4
Time base
From the quartz’s 4.19MHz a time base is derived which controls all timed processes in the scale.
These are, for instance, various timeouts and the on-time.
After expiry of the on-time, the supply voltage for the analog part, for voltage measurement and for the
EEPROM is switched off. The LCD is switched off, all ports are set to zero-signal level and the quartz
is stopped.
Recalibration
In order to compensate for linear measuring errors of the scale, which can, for instance, occur as a
result of the different forces of gravity at different geographical points, the module has a recalibration
function. To initiate the function, another button must be pressed when the scale is started. The
calibration counter is now displayed which is incremented whenever the scale is recalibrated. It
enables the user to check whether the scale was manipulated. If, within five seconds, the button is
pressed longer than 1.5 s, the scale switches to recalibration mode. The scale now measures the zero
point and waits to be loaded with at least ¼ of the maximum load. By briefly pressing the button the
weight displayed can be decremented or incremented in steps of 10g until the weight of the load placed
on the scale is reached. The direction can be changed by pressing the button longer. To stop
recalibration the button must be pressed longer than 5s. The scale can be switched off any time using
the on/off button or by not activating it for a while, thus aborting recalibration.
Optional functions (only DMS low-end module and SLC highend)
The functions “Tare“, “Hold“, “Autohold“ and “Replace weight in repeat measurements” can be
implemented via a program on the EEPROM. The functions are explained below:
Tare:
The tare function can be assigned to a button by the EEPROM program. If the button is pressed, the
weight is tared off as soon as the display has settled, if it is within the permissible range. Pressing the
button again alternatively switches the tare function off or causes the weight to be tared off again.
Hold and Autohold:
If the hold function is assigned to a button by means of the EEPROM, the weight reading is held on
display when the button is pressed as soon as the value has stabilized. Alternatively, the hold function
can be automated so that the weight will always be frozen when it has exceeded a certain threshold
and is stable.
The hold function is switched off after expiry of a predetermined time or by pressing the button again.
In addition the scale can be configured so that the hold function will be deactivated when the scale is
relieved, when the scale is relieved and then loaded again and / or when the load on the scale changes
significantly.
Replace weight in repeat measurements:
The scale can be configured so that the weight last displayed is displayed again in a measurement
when the scale detects that it has been loaded with almost the same weight.
Calibration
To ensure that the module functions properly, data must be written to the EEPROM before the module
is calibrated. Values that are only determined during the calibration process can be set to 0. The
correct figures will then be set after calibration.
If the weight is to be calculated using a third order polynomial, the scale must be calibrated using at
least four test loads. In order to increase accuracy, it is recommended to use even more weights.
If you wish to configure individual temperature compensation, the scale must be measured with a load
and without a load at temperatures on different ends of the range. In order to determine the square
term for slope compensation, the scale must also be measured at an average temperature.
To determine the required calibration values, please refer to the relevant documentation for EEPROM
programming.

Service manual Description of the electronics
05.08.03 /Jensen / Rei 34-34-00-645 b
5
Technical data
Supply voltage: Load cell voltage + 0.5 V to 15 V
Supply current: approximate load cell current
Zero-signal current: typ. 2µA
Operating temperature: approx. 0°C to 50°C
Storage temperature: -10°C to 60°C

30-34-00-618a 25.07.06
QS / Eggers
1
Brief description of the display module
Introduction
The display modules belong to the family of seca electronic modules and are used to display a weight
measured with a suitable module and transferred via the SeSAM bus (Seca’s Serial Autoconfiguring
Multicontroller bus). Furthermore, the display modules accommodate the operating elements and can
process the weight (hold, tare, etc.).
The following block diagram shows the most important function blocks of the display modules:
Display
The weight displayed on the LCD is updated approximately every 0.8s. A maximum of five digits as
well as a few special characters can be displayed, which can appear as shown below:
Explanation of the special characters:
•The battery symbol is used to alert of the fact that the battery is going flat.
•The plug symbol indicates that the scale is operated on a mains transformer.
•The warning triangle signals that the weight displayed on the scale is not verifiable.
•Hold indicates that the weight display has frozen.
•Tare or Net show that a weight on the scale has been tared out.
•The left and right arrows point to additional explanations next to the display.
•The weight units on the right show in which unit the measured weight is displayed.

30-34-00-618a 25.07.06
QS / Eggers
2
Power supply
Power supply is provided via the SeSAM bus.
Operation
With the exception of a start button that might be available, the connected buttons can be configured
as required for the particular model. These buttons can be pressed just lightly or longer (longer than
1.5s).
If you press another button when switching on the scale, the scale will switch to the verification counter
and recalibration mode.
SeSAM bus
The SeSAM bus connects the display modules to the other modules. On this bus the stabilized and
non-stablized supply voltages are available. Via a data and a clock pulse line all relevant data is
exchanged. A special start line is provided via which the scale can be switched on or the module can
signal that it wants to send data.
Identification code
If several display modules are connected, an unmistakable ID code must be assigned to them using
soldering jumpers to ensure that the different modules are correctly addressed via the bus.
Backlighting (optional)
Some display modules are equipped with a power supply for LCD backlighting. It can either be lit when
the scale is switched on or only when the scale is loaded.
Signal transmitter (optional)
Some display modules are equipped with a signal transmitter. A piezo diaphragm is used which is
controlled with a 4 kHz square-wave signal.
Clock module RTC (optional)
Display modules may be equipped with a clock function. If the circuit board is fitted with the relevant
RTC components, when switching on the scale the time is indicated in the display for about 2 seconds.
The power supply of the module results from the supply voltage of the scale. Voltage interruptions are
compensated for a short time
Fault handling
If faults occur, the SeSAM bus initiates a fault message with the relevant fault code. Furthermore, each
fault message includes the number of the module type on which the fault has occurred and a code
which indicates how long the message is to stay on display and which displays are to be suppressed.
The display module displays its own fault messges on its LCD. Module type (for the display module =
3) and fault number are output. In addition, the fault messages that other modules have transferred to
the SeSAM bus are displayed.
The following fault messages are implemented:
14
Fault in the kg value calculation
15 Recalibration fault
30 General bus fault
32 Command buffer full
33 More than 8 slaves detected
50 Other fault
51 Menu fault
Time base
From the quartz’s 4.19MHz a time base is derived which controls all timed processes in the scale.
These are, for instance, various timeouts.

30-34-00-618a 25.07.06
QS / Eggers
3
Recalibration
In order to compensate for linear measuring errors of the scale, which can, for instance, occur as a
result of the different forces of gravity at different geographical points, the module has a recalibration
function. To initiate the function, another button must be pressed when the scale is started. The
verification counter is then displayed which is incremented whenever the scale is recalibrated. It
enables the user to check whether the scale was manipulated. If, within five seconds, the button is
pressed longer than 1.5 s, the scale switches to recalibration mode. The scale now measures the
zeropoint and waits to be loaded with at least ¼ of the maximum load. By briefly pressing the button
the weight displayed can be decremented or incremented in steps of 10g until the weight of the load
placed on the scale is reached. The direction can be changed by pressing the button longer. To stop
recalibration the button must be pressed longer than 5s. The scale can be switched off any time using
the on/off button or by not actuating it for a while, thus aborting recalibration.
Optional functions
The functions “Tare“, “Hold“, “Autohold“ and “Replace weight in repeat measurements” and various
menu functions can be implemented via a program on the EEPROM (on the weight measuring
module). The functions are explained below:
Tare:
The tare function can be assigned to a button by the EEPROM program. If the button is pressed, the
weight is tared out as soon as the display has settled, if it is within the permissible range. Pressing the
button again alternatively switches the tare function off or causes the weight to be tared out again.
Hold and Autohold:
If the hold function is assigned to a button by means of the EEPROM, the weight reading is held on
display when the button is pressed as soon as the value has stabilized. Alternatively, the hold function
can be automated so that the weight will always be frozen when it has exceeded a certain threshold
and is stable.
The hold function is switched off after expiry of a predetermined time or by pressing the button again.
In addition the scale can be configured so that the hold function will be deactivated when the scale is
relieved, when the scale is relieved and then loaded again and / or when the load on the scale changes
significantly.
Replace weight in repeat measurements:
The scale can be configured so that the weight last displayed is displayed again in a measurement
when the scale detects that it has been loaded with almost the same weight.
Menu functions:
Not all the functions listed below can be activated on the same scale.
When the menu button is pressed long enough, the scale switches to the setting mode. Here, damping
and weight display settings can be made.
When the button is pressed briefly, the scale switches to function mode. The following functions are
possible:
•BMI: From weight and height the body mass index is calculated using the following formula
BMI weight kg length m= [ ]/ [ ]
2BMI = weight [kg]/ height [m]2.
•IDE: The deviation from the ideal weight calculated using the formula
09 100, ( [ ]
)
× -lengthcm 0.9 (height[cm]-100) is displayed.
•UL: When a limit weight is overshot or undershot an acoustic signal is generated.
•DIFF: The difference to a second weight is output. The second weight can have been measured
using the autohold function, entered manually or stored when the difference function was last
called.

30-34-00-618a 25.07.06
QS / Eggers
4
Technical data
Supply voltage: 2.7V -3V and 2.7V -15V (via SeSAM bus)
Supply current: typ. 0.5mA + power supply for backlighting (typ. 100mA)
Quiescent current: typ. 2µA
Operating temperature: approx. 0°C to 50°C
Storage temperature: -10°C to 60°C
Dimensions: 74mm x 50mm x 23mm small display
100mm x 84mm x 21mm large display
67mm x 38mm x 23mm backlit display

optional
optional
optional





Service manual Description of faults
20.02.01/Winterberg 1 (2) 30-34-00-588 index c
Please refer to the operating instructions to ensure that the scales were operated in the proper
Please refer to the operating instructions to ensure that the scales were operated in the properPlease refer to the operating instructions to ensure that the scales were operated in the proper
Please refer to the operating instructions to ensure that the scales were operated in the proper
manner. In case of a malfunction, the following table will help you to locate the fault.
manner. In case of a malfunction, the following table will help you to locate the fault.manner. In case of a malfunction, the following table will help you to locate the fault.
manner. In case of a malfunction, the following table will help you to locate the fault.
Description of the
fault
Possible
cause
Remedy
Scales cannot be
started •Battery is not
installed or
discharged
•Check the batteries
•Voltage supply
is defective •Check the voltage at the appropriate connections of the electronics; eliminate the interruption
•Bus
connection
cable is
defective
•Check the plug-in connections; check the cables for interruption
and replace them if necessary.
•Keypad is
defective or
not connected
•Check the cable connections; check the cables and the keypad
for interruption and replace them if necessary
•Bus fault •Disconnect power supply unit and battery from the scale, wait for
60 seconds, then reconnect.
Scales show no
weight or an
incorrect weight
(repeatedly)
•Packaging /
transport
safeguard has
not been fully
removed
•Check the scales
•Scales are
maladjusted •Recalibrate the scales
•Sensor is
damaged •Replace the sensor and recalibrate the scales
•Load lever
system is
damaged or
transfer of
force to the
sensor is
interrupted
•Check the base frame (if present, the tie rod) for damage or
incorrect assembly
Scale shows only
the segment test or
the readings are
varying to much.
•Shortcircuit
between
sensor cable
and housing
•Search for damaged isolation of the cabel and repair it. ( If
appropriated use multimeter.)
Incomplete digits •Display is
defective •Replace the electronics
Malfunction during
the weighing
procedure
•Display:
Er:x:no
•The electronics have detected an error.
!X: module number
!No: error number
•Er:x:10 •Sensor is
defective or
not properly
connected
•Check and, if necessary, replace the sensor (if the sensor is
replaced, a recalibration is required)

Service manual Description of faults
20.02.01/Winterberg 1 (2) 30-34-00-588 index c
Description of the
fault
Possible
cause
Remedy
•Er:x:11 •Sensor is
defective or
supply lines
are damaged
•Check connection cables, check sensor and replace as required
(if parts a replaced, a recalibration is necessary)
•If several load cell are used, check the allocation (colour codes)
•Er:x:12 •Initial load is
too high •Check the initial load
•Check the load lever (stuck or bent; check the sensor, replace it if
necessary and carry out a recalibration
•Er:X:14 •Error during
calculation of
the kg value
•Incorrect coefficient in the read-only memory of the module;
recalibrate the scales
•Er:x:15 •Error during
recalibration •Reference weight is outside the permissible range or operator error
•Er:x:21 •Error while
measuring the
battery voltage
•Battery voltage is far too low (< 2.5 V) or electronics are defective
-> Replace the electronics
•Er:x:22 •Error while
measuring the
temperature
•Replace the electronics
•Er:x:32 •Error:
command
buffer overflow
•Check the cabling of the bus, eliminate any EMC malfunction,
briefly (60 sec.) de-energize the electronics
•Er:x:40 •No EEProm
data •Recalibrate the scale or write the correct EEProm data by service program
•Er:x:41 •Incorrect
EEProm
access by the
slave
•Check the slave; disconnect or replace the slave
•Er:x:50 •Other errors •Error occurs directly after switching on -> wrong checksum in the
ROM
-> Replace the electronics
•Er:x:51 •Menu error •Incorrect use of a menu function (wrong data e.g.), try it again

Vogel & Halke
Created on: 30.06.1998
Holger Panier / SE
File: 00603_e1.doc
Printed on: 07.07.1999 seca
Page -1-
00603_e1.doc
Description of the calibration mode for scales with modularDescription of the calibration mode for scales with modular
electronicselectronics
General:General:
Seca scales with modular electronics are fitted with a software-controlled calibration device
that is operated using the existing controls. This device can be used to recalibrate the
scales or to set the scales to different GAL values. During development of the calibration
device, special attention was paid to the following requirements:
• It must be possible to recalibrate the scales without any additional external
equipment/tools.
• It must be possible to calibrate the calibration device.
• It must be possible to recalibrate the scales without calibrated test weights.
• The calibration device shall be protected against inadvertent use.
Calibration counterCalibration counter
The scales fitted with the new, modular electronics are equipped with a calibration counter
allowing a software recalibration to be carried out according to the requirements for
calibrated scales. To carry out such a recalibration, the calibration counter setting can be
called up on the display of the scales and compared to the data given on the calibration
label mark (applies only for calibrated products). If the values are identical, the scales are
calibrated; whereas differing values match the situation of a broken calibration seal. Each
completed recalibration procedure is registered by the calibration counter, i.e. the number is
automatically incremented by 1.
Recalibrating the scalesRecalibrating the scales
Before the scales can be recalibrated, they must be switched to the calibration mode:
To do so, switch on the scales using the appropriate control. While doing so, simultaneously
press another control key (for example, the kg/lbs key). This causes the contents of the
calibration counter (i.e. the number of calibration procedures carried out so far) to be
displayed for five seconds (flashing).
During the 5 seconds the contents is displayed, press the kg/lbs key again and keep it
depressed (for more than 1.5 seconds) to switch the scales to the calibration mode.
If the kg/lbs key is not pressed within these 5 seconds, the scales are automatically
switched back to normal weighing operation.
When switched to the calibration mode, the scales first are in a decrementing state. This
state is indicated by a flashing "dec" that alternates with the currently measured weight.
Now place a test weight onto the scales. This test weight should have a weight of at least
25% of the maximum permissible load for the weight (we recommend a weight of approx.
66-75%). The weight shown on the display must match the test weight; otherwise, the
scales are maladjusted and the recalibration procedure must carried out in full length. To do
so, change the weight shown on the display using the kg/lbs key until it matches the test
weight.
If the value shown on the display differs from the test weight (if not, recalibration is not
required), estimate whether the required nominal weight is easier to reach by decrementing
or by incrementing. To toggle from the decrementing mode to the incrementing mode or
vice versa, press the kg/lbs key for more than 1.5 seconds (display indicates dec or inc).

Vogel & Halke
Created on: 30.06.1998
Holger Panier / SE
File: 00603_e1.doc
Printed on: 07.07.1999 seca
Page -2-
00603_e1.doc
Pressing the kg/lbs key for less than 1.5 seconds causes the weight shown on the display
to be increased or decreased by 10 g (depending on the mode currently selected). As the
resolution of the display is lower, the displayed value will not necessarily be increased or
decreased each time the kg/lbs key is pressed. Repeat the above procedure until the
displayed weight and the test weight match. Set the scales to the middle between two
division values by additionally incrementing or decrementing the value by n=d/(2*10). The
calibration process can now be completed by pressing the kg/lbs key for at least five
seconds. The scales compute and store a new linearity coefficient and will then be switched
off automatically. The scales are now calibrated. Remove the test weight.
Note:
To prevent improper calibration by improper use, a timeout control has been implemented
in the calibration mode, i.e. the time that passes until the next key is pressed must never
exceed five seconds.
However, this timeout control is only active for the phase when switching to the calibration
mode.
If, during this phase, 5 seconds have passed and no key has been pressed, the scales are
automatically restored to the weighing mode so that the procedure must be repeated.
To reduce calibration errors to a minimum, recalibration is only possible using a test weight
of more than 25% and less than 100% of the max. load; otherwise, “Er:0:15” will appear
on the display.
If the scales need to be set to a different GAL value, the displayed value must be matched
to the test weight value adapted to the GAL value correction.
Example of a recalibration procedure:
The selected test weight is 100 kg.
The current weight shown on the display is 99.7 kg (max. difference of 300 g).
In this example, you must switch the scales to the incrementing mode to carry out the
recalibration procedure. After the kg/lbs key has been pressed (for more than 1.5 seconds),
a flashing "inc" is shown.
Now increase the value by the first 10 g (by briefly pressing the kg/lbs key). After this has
been done thirty times, the value 100.0 (rounded!) appears on the display although the
internal measured value still is 99.95 kg (not rounded!).
To correct this rounding error, increase the value by another 10 g to get exactly 100.00 as
the calculated value.
Terminate the recalibration procedure as described above.

Vogel & Halke
Created on: 30.06.1998
Holger Panier / SE
File: 00603_e1.doc
Printed on: 07.07.1999 seca
Page -3-
00603_e1.doc
Summary of a typical recalibration sequence:Summary of a typical recalibration sequence:
Action carried out by the user Result
The scales are switched off. No values or characters on the display.
Press the kg/lbs key and keep it depressed
while simultaneously pressing the start key. The contents of the calibration counter is shown on the display for 5 seconds
(flashing).
Release both keys. The contents of the calibration counter is
shown on the display for 5 seconds
(flashing).
Press the kg/lbs key for more than
1.5 seconds within the next 5 seconds. The system switches to the calibration mode: first "dec" appears on the display (flashing)
and then the current weight (0.0 - also
flashing).
5 seconds have passed and no key has
been pressed. The scales are switched back to normal weighing operation.
Place the test weight onto the scales. The measured weight of the test weight
appears on the display (flashing).
Decide whether to decrement or to
increment:
Incrementing:
Press the kg/lbs key for more than 1.5
seconds.
Decrementing:
No action required as the scales are already
in the dec mode.
The incrementing mode is activated; "inc"
appears on the display.
No output on the display.
Decrementing or incrementing:
Again briefly press the kg/lbs key (for less
than 1.5 seconds).
The measured weight is decreased or
increased by 10 g. Please remember that
pressing the key does not always change the
value on the display due to the low display
resolution. Only the rounded value is given.
Repeat this step until the measured weight
matches the test weight (format: xx.0 kg). The display indicates the test weight (format: xx.0 kg).
To correct this rounding error, decrement or
increment the value five times by another
10 g.
The display output does not change the first
four times.
After the fifth time the value has been
decremented or incremented, the measured
weight appears; it now matches the test
weight.
The display indicates the exact test weight
(format: xx.00 kg).
Press the kg/lbs key for at least 5 seconds
until the system is switched off. The display does not show any characters or values any more.

Service Manual Replacement instructions
02.05.05 / Rei 1/4 30-34-00-720
seca 703 / 704 CN
Removing the power supply
Before starting any work unplug the mains plug and remove the batteries!
ESD protection measures must be taken whenever work is performed on electronic components.
1. Opening the scale
When replacing
-platform load cell "P", DMS –Basic "D", mains connection "N", follow the instructions in sections
1.1 to 2.3 (page 3)
-display board "AP", battery connection "BA", membrane keyboard "FT" follow the instructions in
section 2.4 (page 4)
1.1 Turn the scale over and set the platform surface "B" on a table (table height min. 900 mm) or a
similar worktop (page 3, diagram 1). Slacken the 4 M4 hex. nuts "A".
1.2 Turn the scale over again and lift off the platform hood "B".
2.Replacing
2.1 DMS Electronic module "D" (page 3)
It is not necessary to remove the load cell to replace the DMS Electronic module.
Detach plug-in connections "S1" and "S2" from the DMS Electronic module and then release the
2 M5 oval head screws "L". Carefully take off the cover, slacken the 2 screws "P" and take out the
board.
Unsolder the cable connections "K1" and "K2" from the electronic module.
The electronic module can now be replaced.
2.2 Platform load cell "P" (page 3)
To replace the platform load cell unsolder the cable K1 to the DMS Electronic module as
described in section 2.1. Then slacken the 4 M6 cheese head screws "Z1". Slacken the 4 M4 hex
nuts "A". Carefully turn the scale over. Unscrew the 4 M6 cheese head screws "Z2" from the
platform support and remove the platform support. The load cell can now be replaced.
2.3 Replacing the cable harness for the mains plug "N" (page 3)
The cable harness can only be replaced when the column is removed.
Before replacing the cable harness for the mains plug, cable "K2" must be unsoldered from the
DMS Basic module and the 2 screws "SV" fixing the column connection element must be
released. Unscrew the 2 M2 cheese head screws "Z3" and replace the cable harness.

Service Manual Replacement instructions
02.05.05 / Rei 2/4 30-34-00-720
2.4 Replacing display board "AP", membrane keyboard "FT" and battery connection "BA"
(page 4)
Unscrew the 4 M6 countersunk screws "C1" from the side covers.
Unsolder the cable connections from the parts to be replaced.
Display board "AP": Slacken the four fixing screws "P2" and detach the plug "S3" of the cable
connection from the bottom part.
Membrane keyboard "FT": Carefully detach the membrane keyboard "FT" (glued on) and pull the
panel housing "BG" off to the left.
3.Closing the scale
3.1 Reassemble the scale in reverse order, following the instructions given in sections 2.4 to 1.1.
Warning !
When the DMS Electronic module and the platform load cell are replaced, the scale must be re-
adjusted. Follow instructions no. 30-34-00-603.
When replacing electronic components, observe cabling diagram 08-02-06-032.
3.2 Apply for official calibration of the scale.