KERN RPB Service Manual
KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen-Frommern
E-Mail: info@kern-sohn.com
Tel: 0049-[0]7433- 9933-0
Fax: 0049-[0]7433-9933-149
Internet: www.kern-sohn.com
GB
Service Manual
Price Computing Scale
Page 2
KERN RPB
Version 1.0 08/2006
CONTENTS
1 INTRODUCTION................................................................................................. 3
2 TROUBLESHOOTING ........................................................................................ 4
3 CALIBRATION .................................................................................................... 5
3.1 JUMPER AND SEALS ................................................................................. 5
3.2 CALIBRATION PROCEDURE ..................................................................... 6
4 SERVICE PARAMETERS................................................................................... 7
4.1 F1 – CALIBRATION....................................................................................... 8
4.2 F2 – RESOLUTION....................................................................................... 8
4.3 F3 – CAPACITY............................................................................................ 9
4.4 F4 – WEIGHT DECIMAL POINT POSITION................................................. 9
4.5 F5 – UNIT PRICE/TOTAL PRICE DECIMAL POINT LOCATION................. 9
4.6 F6 – INITIAL ZERO RANGE....................................................................... 10
4.7 F7 – RE-ZERO RANGE............................................................................... 10
4.8 F8 – SUCCESSIVE TARE .......................................................................... 10
4.9 F9 – A/D COUNT........................................................................................ 11
4.10 F10 – ROUNDING OFF THE TOTAL PRICE .............................................. 11
5 WIRING DIAGRAM ........................................................................................... 12
6 MECHANICAL ASSEMBLY............................................................................... 13
6.1 EXPLODED DRAWING ............................................................................. 13
6.2 LIST OF MECHANICAL ASSEMBLY......................................................... 14
7 SCHEMATICS AND COMPONENTS LAYOUT ................................................ 15
7.1 FRONT DISPLAY SCHEMATIC ................................................................. 15
7.2 MAIN PCB ASSEMBLY.............................................................................. 16
7.3 MAIN SCHEMATIC LAYOUT..................................................................... 17
7.4 PILLAR DISPLAY SCHEMATIC................................................................. 18
7.5 REAR DISPLAY SCHEMATIC................................................................... 19
2 RPB-SH-e-0610
1 INTRODUCTION
The RPB series of digital price-computing scales provide an accurate, fast and
versatile method of computing price by weight.
For all revisions from 1.27 and above, the price per kilogram and per 100 gram
key can be disabled at the factory for the scales to be used in South Africa and Far
East. This is done by linking the jumper at K5 position on the PCB.
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 KERN & SOHN GMBH 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.
RPB-SH-e-0610 3
2 TROUBLESHOOTING
1. Unit does not
turn on
Check whether the scale is plugged into the power supply properly.
Check the operation of the charging circuit.
Check whether the battery is charged- LED should turn to green
from red.
Check the adapter output.
2. The scale
weighs but is
unstable
Air drafts or vibration or unstable table.
Pan rubbing against case or not installed correctly.
Sample is moving (animal weighing).
Scale not installed properly.
Improper connections on ADC circuit.
3. Scale shows
wrong weight
Scale not installed correctly.
Check the Calibration.
To check whether a part of product weighed is trapped between
the pan and the scale.
Incorrect adjustment of the mechanical stops.
4.
An error “E4”
displays on
the screen
Load cell damage.
Scale not installed properly.
Incorrect adjustment of the mechanical stops.
Factory calibration has been tampered with- check the ADC counts
and re-calibrate.
5.
An error “E9”
displays on
the screen
The scale is not stable to set the initial zero.
Air drafts or vibration or unstable table.
Electronics may be damaged.
4 RPB-SH-e-0610
3 CALIBRATION
3.1 JUMPER AND SEALS
1. Bottom of the balance
Access to conductor plate:
• Place your balance upside down
• Remove seal
• For verified balances, the jumper is on a pin
• For adjustment the jumper must be set on both pins
Position jumper for adjustment
2. Top of the balance
• Remove weighing plate
Position
of seal
Sealing by seal or by lead
seal
RPB-SH-e-0610 5
3.2 CALIBRATION PROCEDURE
For verified balances calibration by means of a jumper is locked. In order to carry out
calibration the two contacts of the conductor plate must be shorted with a jumper in
K6 position (see chapt. 3.1).
If the hole is not provided in your scale, the security seal has to be broken to remove
the top cover and gain access to the main PCB. Replace the cover and install the
screws before starting the calibration.
Observe stable environmental conditions. A warming up time of approx. 10 minutes
is required for stabilization. Ensure that there are no objects on the weighing plate.
After the jumper has been placed in position K6, apply power to the scale.
During the self-test press the key.
The display will ask for a code number, “Pn - - - -“ on the Weight Display.
To carry out the calibration, enter the number “0000” then press . The display will
show “CAL F1” will be enabled. Press the key.
The display will show “UnloAd” asking you to remove any weight from the scale.
Press the key.
The display will tell you to add weight to the scale by showing “LoAd” “15” “kilo”
Add the weight shown, wait for stability then press the key.
The display will show “
SPAn” “PASS” if the calibration is OK.
Or it will show “SPAN” “FAIL” if calibration could not be completed correctly.
The scale will return to the parameter menu (“CAL F1”).
Return to weighing mode by pressing the
key.
Back to calibration process by pressing the key.
6 RPB-SH-e-0610
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