GMK III

EKS4
Rated Capacity
Indicator
Rated Capacity Indicator 1
General description 2/4
EKS 4 System Overview 5
Component locations 6
Central unit interface 7
Central unit inputs 8
Central unit outputs 9
Central unit circuit boards 10
Technical data 11
Main boom pressure sensors 12
Main boom angle sensors 13
Main boom external length sensors 14
Telescope cylinder length sensors 15
Analogue / digital converter boards 16
Analogue / Digital board address codes 16
Resistor boards 18
Swingaway lattice (PTJ) 19
Pressure sensors 19
AngIe sensors 20

EKS 4 System
 GMK III

EKS4
Rated Capacity Indicator

EKS 4

E ft no no no

ft ft no % ft

i 1 2 3
klbs
max

klbs

II I
t no

n=

00
ft

F1 1 2 3 4 5 CE

F2 6 7 8 9 0

Figure 1: Central Unit

EKS 4 System 1
 GMK III

General description
Central unit

The design and development of the EKS 4 Rated Capacity Indicator is carried out “in-
house” by the electronic engineering department TK4 at Deutsche GROVE.

The new EKS 4 is a stand-alone system installed to meet all operating requirements for
mobile cranes. Due to the unique design, a very high degree of system immunity exists
from external interference (radio transmission etc.). The system safety is further
enhanced by a CAN-Bus data exchange with the ECOS management system.

The system comprises a central unit, which is installed in the cab instrument panel and
connected to remote sensors via CAN-Bus. The central unit is a totally integrated unit,
containing all the system software with a semi-graphic display and digital information
presentation to the crane operator (fig.1).

The crane operator has all important operating status information continuously displayed
with further information levels available by membrane (touch-pad) switch selection.

All information displays are located on the central unit face pla te along with membrane
(touch-pad) switches to allow the operator to enter status acknowledgment or changes,
and access configuration or error code display information (fig1).

The alphanumeric membrane switches for operating status acknowledgment or entering

new configuration/service requirements are located horizontally on the bottom of the
central unit faceplate. Additional membrane switches are located on the faceplate with a
covering graphic to indicate the switch function (fig.1).

Note: The key-switch mounted on the faceplate has no operator function and is provided
for service purposes.

Sensors:
The external sensor system is of redundant design for all primary functions. This
provides two sensors for each measured value. The sensors are placed as close as
possible to the value being measured. The measured values are then transmitted to the
central unit by CAN-Bus where the information is then processed.

The electro-hydraulic pressure sensors (transducers) are installed directly in the boom lift
cylinder: two sensors for the piston side and one for the rod side pressure. One sensor is
acceptable for the rod side pressure, as it does not carry the safety implications of the
piston side pressure measurement. The measured values are converted internally and
transmitted via CAN-Bus to the central unit for processing.

The main boom angle measurement is provided by two pendulum driven potentiometers,
which are fitted inside an aluminum housing box mounted on the left side of the boom
base section. Two analogue to digital converter boards are mounted within the housing

EKS 4 System 2
 GMK III
box, one below each potentiometer. This allows direct conversion of the measured
analogue value to a digital signal, which is then transmitted via CAN-Bus to the central
unit for processing.

External boom length measurement is provided by two potentiometers, which are fitted
inside a recoil drum mounted on the left side of the boom base section. Two analogue to
digital converter boards are mounted within the drum adjacent to each potentiometer.
This allows direct conversion of the measured analogue value to a digital signal, which is
then transmitted via CAN-Bus to the central unit for processing.

The external boom length recoil drum is driven by a multicore length measuring cable
and has * 18 slip-ring circuits. These slip-ring circuits provide the necessary connections
to the main boom head for the hoist limit switch and the wind speed indicator functions.
Additionally, when the swing away jib (PTJ) is installed extra circuits are required for the r
rated capacity indicator sensors installed on the jib, the manual operating switches on
the jib and the proportional throttle valve used to control the (PTJ) derricking speed.

Telescope cylinder length measurement is provided by two potentiometers, which are

fitted inside a recoil drum mounted inside the boom directly under the piston rod anchor
point. Two analogue to digital converter boards are mounted within the drum adjacent to
each potentiometer. This allows direct conversion of the measured analogue value to a
digital signal, which is then transmitted via CAN-Bus to the central unit for processing.

The central unit processor calculates the boom length, based on the telescope cylinder
length and pinning cycles, with a comparison check of the external length measuring
data. Additionally, the CAN-Bus data exchange with ECOS is used to compare length
data.

The telescope cylinder length recoil drum is driven by a multicore length measuring
cable and has *26 slip-ring circuits. These slip-ring circuits provide the necessary
connections to the proximity switches and solenoid valves mounted on the
telescope cylinder barrel, as it extends or retracts.

Swingaway lattice (PTJ) * optional equipment

The swingaway lattice is a bi-fold lattice jib with a hydraulic cylinder controlled from the
o o
operator’s cab to give offset angles from - 5 to + 40
Sensors:
The electro-hydraulic pressure sensors (transducers) are installed directly in the lift
cylinder: one for the piston side and one for the rod side. The measured values are
converted internally and transmitted via CAN-Bus to the central unit for processing.

The jib angle reference to horizontal is measured by a pendulum driven potentiometer

fitted inside an aluminum housing box mounted on the left side of the jib base section.
An analogue to digital converter board is mounted below the potentiometer. This allows
direct conversion of the measured analogue value to a digital signal, which is then
transmitted via CAN-Bus to the central unit for processing.

EKS 4 System 3
 GMK III

The jib offset angle reference is measured by a rotary potentiometer fitted to the pivot
point of the jib. The potentiometer is driven by a mechanical lever connection between
the fixed member attached to the boom head and the moveable member attached to the
lift cylinder. The potentiometer output signal is routed to an analogue to digital converter
board mounted within the same housing box as the horizontal angle A/D board where it
is converted and transmitted to the central unit via CAN-Bus for processing.

* The slip ring contact circuits are made of specialist materials matched to their
application requirements. Silver is used for high current and Rhodium is used for low
current circuits.

NOTE: The term “Rated Capacity Indicator” will be replaced with the acronym RCI
throughout the rest of this document.

Digital multilevel inputs:

Digital multilevel inputs from telescope cylinder proximity switches for locking position of
the cylinder, locking status of the telescope cylinder pins and locking status of the boom
section pins are routed to EKS 4 via resistor board circuits. The resistor boards carry out
continuous circuit integrity checks and can identify circuit errors. Additional direct 24volt
digital inputs are to confirm actuation of the by-pass key and give release signals for the
main and auxiliary hoists.

Operational aspects
During operation of the crane the RCI constantly compares the current load with the
programmed permissible load value. The current load and permissible load are on
constant display at the central unit faceplate. Before reaching the maximum permissible
load limit, the RCI will emit an audible alarm when the warning limit is reached. If the load
is increased further, the RCI stops all crane movements that increase the actual load
value, once the maximum load limit is reached.

The RCI does not automatically register the entire crane operating factors that are
necessary for calculation of the permissible maximum load. The operator must enter the
following factors (operational / reeving mode) via the membrane switches on the central
unit faceplate.

Reeving

Outrigger spread

Installed counterweight

Length of lattice extension (PTJ)

If the factors entered by the operator do not represent the actual condition of the crane,
the maximum permissible load calculated by the RCI will be incorrect. An incorrect entry
may give the crane operator a false sense of security. The consequences can then be
overloading of the crane and I or an accident.

EKS 4 System 4
 GMK III

Switches located at the head of the boom and any installed jibs actuate the hoist limit
system. This disconnects all movements that could increase the load moment (hoist
raise, boom down and telescope out) when the hook lifts the weight connected to the
switch. The switching signal is transmitted through the length measuring cable to the
boom base section and from there to the crane electric system. The hoist limit system
operates totally independently of the RCI system

EKS 4 System 5
 GMK III
Component locations

Jib horizontal angle sensor Jib offset angle sensor

External boom length sensors

Main boom angle sensors

Pressure sensors

Telescope cylinder length unit

Central unit

Figure 3: Overview of EKS 4 component locations

EKS 4 System 6
 Eks 4 System Overview
CAN-Bus 1

CAN-Bus 2
CAN-Bus 4

External drum Main boom

Lift Cyl. piston Tele. cylinder
EKS 4
EKS 4 System

8.8. 8.8. 8.8. 8.8. 8.8.

8.8. 8.8. 8.8. 8.8. 8.8.
ECOS ft Pressure sensor A no Length Trans. A
************************** Length Trans. A Angle Trans. A
ECOS
E ft no no no
SYSTEM OK!
**************************

F1 F2 F3 F4 F5 Esc Enter External drum Main boom

! Lift Cyl. piston Tele. cylinder

ft
ft ft no % 8.8. 8.8. 8.8. 8.8. 8.8.

i 1 2 3 ft Pressure sensor B no Length Trans. B

klbs
Length Trans. B Angle Trans. B
max

Lift Cyl. rod

klbs

Swingaway (PTJ) Swingaway (PTJ)

II I Pressure sensor A Lift Cyl. piston
t no

n= no Pressure sensor A
00 Angle Trans. A
ft
12-7

Swingaway (PTJ) Swingaway (PTJ)

F1 1 2 3 4 5 CE
Lift Cyl. rod
F2 6 7 8 9 0 ENT Relays
12 outputs Digital inputs
Potential - free 22 multilevel inputs no Pressure sensor A
Angle Trans. B
 GMK III
Central unit interface

12 relays for potential-free outputs

Output fuses 5A Main fuse 5A

X9

X1 X2 X11
Plug identity key symbols

X3 X4 X5 X6 X7 X8

Interface Legend:
X1 =Relay outputs X6 = CAN-Bus 2 (Main boom)
X2 =Relay outputs X7 = CAN-Bus 3 (Not used)
X3 =Digital inputs X8 = CAN-Bus 4 (ECOS)
X4 =Digital inputs X9 = Power supply
X5 =CAN-Bus 1 (PTJ) X11 = Program connection

See Schematic 03046657 for t/m

See Schematic 03046658 for lbs/ft
See Electric group =35 & =37 for connection interface
See Tables 1 & 2 for description of inputs & outputs

Figure 4: Rear view of EKS 4 central unit

EKS 4 System 8
 GMK III
Central unit inputs

EKS 4 Central unit inputs

Contact Type Plug/pin Dual connection Signal Function description Connection
ID reference with ext bridge ID with signal voltage

Input 1 Dual X3.1 No Recognition of telescope HS_2000R

cylinder locking point A
E1
Input 11 Dual X3.3 No Recognition of telescope HS_2000R
cylinder locking point B

Input 5 Dual X3.13 No E5 Main hoist enabled Without RB

Input 7 Dual X3.15 No E7 Auxiliary hoist enabled Without RB

Input 12 Dual X4.1 No E12 Boom section pins locked HS_2000R

Input 13 Dual X4.4 No E13 Left telescope cylinder pin HS_2000R

locked

Input 14 Dual X4.7 No E14 Right telescope cylinder HS_2000R

pin locked

Input 17 Mono X4.14 - E17 By-pass RCI Without RB

Allowable type of high-side resistor boards

Type

HS_2000R “ High-side” switch, one connection contact is connected to the battery, the other contact
is connected with the signal line via the HS_2000R (2000 Ohm resistor board) to ground

Note: The supply and ground connection to the input switches are to be carried out low-Ohmic
to the supply or ground connection of the RCI. (with “ high-side” switches ground
connection resistor). The voltage drop in the lines of the input switches must not exceed
2.5 volts.

*Without RB = Without “ high-side” resistor board

* Note: Three of the above digital inputs do not have a resistor board in the circuit; in this
case the central unit will only detect three switched states within the program parameters:
1. Short to ground 0 - 3Volts =O
2. Open circuit 9 - 15 Volts = C
3. Switch closed 19 - 24 Volts = F

See page 18 for resistor board circuit details.

See Electrical group schematic =37/3 & /6 for connection details.

EKS 4 System 9
 GMK III
Central unit outputs

EKS 4 Central unit micro relay outputs

Relay Contacts Plug/pin reference Function description Reaction
Contact definition De-energised status Relay status
N/O Common N/C

K1 N/O X1.3 X1.2 - RCI failure K1-K12 de-energised

K1 contacts open
K2* N/O X1.6 X1.4 - Cut-off display* K2 de-energised
K2 contacts open
K3 N/O X1.9 X1.7 - Cut-off main hoist raise K3 de-energised.
K3 contacts open
K4 N/O X1.12 X1.10 - Cut-off derrick out K4 de-energised
K4 contacts open
K5 N/O X1.15 X1.13 - Cut-off telescope out K5 de-energised
K5 contacts open
K6 N/O X2.3 X2.1 - Cut-off auxiliary hoist raise K6 de-energised
K6 contacts open
K7 N/O X2.6 X2.4 - Cut-off derrick in K7 de-energised
K7 contacts open
K8 N/O X2.9 X2.7 - Cut-off telescope in K8 de-energised
K8 contacts open
K9 N/O X2.12 X2.10 - Cut-off auxiliary hoist lower K9 de-energised
K9 contacts open
K10 N/O X2.15 X2.13 - Cut-off jib (PTJ) derrick out K10 de-energised
K10 contacts open
K11* Changeover X1.11 X1.8 X1.14 Pre-warning display * K11 de-energised
K11 contacts closed
K12 Changeover X2.11 X2.8 X2.14 Cut-off jib (PTJ) derrick in K12 de-energised
K12 contacts open

* K2 & K11 will only be wired for external outputs where this option is required to meet
mandatory country regulations. Therefore, you will not see these relays on the standard
group = 37 electrical schematic diagrams.

See Electrical group schematic =37/3 for connection details

EKS 4 System 10
 GMK III
Платы центрального блока

Конструкция центрального блока представляет собой алюминиевый корпус с

направляющими для облегчения сборки печатной платы. Каждая слотовая плата
имеет многоконтактный разъем в нижней части платы для соединения с
интерфейсным разъемом платы, который находится в нижней части устройства.
Плата дисплея прикреплена к лицевой панели.

3 3a

Legend:
1. Плата разъема подключения
2. Плата ввода/вывода
3. Плата ЦП
3a. *На плате ЦП имеются внутренние индикаторы ошибок (белые/красные индикаторы).
4. Адаптерная плата
5. Дисплейная плата

* Они имеют смежные кнопки тестирования для имитации/очистки внутренних

ошибок. Если они загораются во время обслуживания, это будет означать
серьезную ошибку ЦП.

EKS 4 System 11
 GMK III
Технические данные

Центральный блок:
Напряжение питания 18 — 32 вольт Потребляемый ток = 1 А
4 x 4-проводные системы CAN-Bus
22 многоуровневых цифровых входа
12 релейных выходных контактов без потенциала

Voltage: 18 — 32v
Current: 3A
Предохранители:
Один главный предохранитель 5 А
Двенадцать предохранителей 5 А, по одному на каждый релейный выход
Каждая цепь CAN-Bus имеет биметаллический
Диапазон температур: — от 25 до +70 °C
Примечание: отказ предохранителя на релейных выходах может быть обнаружен
как ошибка только тогда, когда конкретная цепь находится под нагрузкой.

Функции программного обеспечения:

Выбор диаграмм грузоподъемности:

Индикатор номинальной грузоподъемности выбирает соответствующую диаграмму
грузоподъемности в соответствии с выбранным режимом работы и текущей
конфигурацией стрелы. Возможны дополнительные критерии выбора диаграммы
грузоподъемности, например: цифровые входы для подтверждения того, что
штифты стрелы заблокированы или углы стрелы/гусек выходят за пределы
указанного диапазона.
Расчет радиуса:
Радиус можно рассчитать, принимая во внимание коэффициент отклонения, длину
и угол стрелы, а также гидравлическое давление, измеренное в подъемных
цилиндрах.
Оператор должен ввести подтверждение существующего состояния конфигурации
или ввести любые изменения в состояние конфигурации крана.

EKS 4 System 12
 GMK III
Уставки:
Используя радиус, соответствующие уставки (допустимая нагрузка для данного
режима работы) могут быть установлены из спецификаций момента нагрузки.
Существует снижение допустимой нагрузки в зависимости от выбранного режима
запасовки.

EKS 4 System 13
 GMK III
Датчики давления главной стрелы
Датчики давления подъемного цилиндра (преобразователи) используются для
измерения нагрузки на основную стрелу. Датчики давления (преобразователи)
установлены на стороне поршня и на стороне штока подъемного цилиндра: два на
стороне поршня и один на стороне штока. Один датчик на стороне штока
приемлем, так как функция компенсации не является критичной для безопасности
(рис. 6). Датчики давления преобразуют измеренное значение и передают
информацию через CAN-Bus в центральный блок для обработки. Каждому датчику
давления присваивается уникальный идентификатор, чтобы центральный блок мог
распознавать источник сигнала. Индивидуальная идентификация датчика
достигается путем подключения к земле через соединительный мост, который
является уникальным для конкретного датчика (рис. 6).

5
4

CAN-Bus out
CAN-Bus In

3
1

Legend:
1. Датчик давления поршня 1 (А)-А101 нижняя камера
2. Датчик давления поршня 2 (В)-А102 нижняя камера
3. Датчик давления штока (А)-А103 верхняя камера
4. Распределительная коробка датчика давления шины CAN (-A105, рядом с
блоком автоматической смазки)
5. Идентификационный код датчика давления 1 (пример).
См. схему 03011100 для полной системы
См. схему 3008374 для деталей распределительной коробки
См. схему электрической группы =37/4 для деталей соединения

EKS 4 System 14
 GMK III
Датчики угла наклона главной стрелы
Для контроля угла наклона главной стрелы от —1,5o до +84o в алюминиевом корпусе с
левой стороны секции основания главной стрелы установлены два потенциометра с
маятниковым приводом. Угол изначально измеряется как аналоговое значение, а затем
немедленно преобразуется в цифровую информацию для передачи по шине CAN в
центральный блок для обработки. Для выполнения этой задачи две платы аналого-
цифрового преобразователя устанавливаются в том же корпусе непосредственно под
соответствующими потенциометрами. Каждому датчику угла присваивается
уникальный идентификатор, позволяющий центральному блоку распознавать источник
сигнала. Индивидуальная идентификация датчика достигается путем установки
индивидуального кода адреса на каждую плату аналого-цифрового преобразователя
датчика. Кроме того, сигнал устанавливается на угол путем разрезания небольшого
моста (соединительного провода) на платах аналого-цифрового преобразователя.

A
B

Угол наклона главной стрелы

потенциометры = 1,28кОм
Адресный код АЦП: Датчик А
=0
Датчик В = 8
Address code *Экраны кабелей должны
покрывать всю площадь
сальника.
См. схему 03011100 для полной системы
См. схему 03011073 для установки угловой коробки –
A110 См. таблицу 3 для списка кодов адресов

Рисунок 7: Вид датчика угла наклона основной стрелы –A110

EKS 4 System 15
 GMK III
Датчики внешней длины основной стрелы
Измерение внешней длины стрелы осуществляется двумя потенциометрами,
которые установлены внутри барабана отдачи, установленного на левой стороне
секции основания стрелы. Две платы аналого-цифрового преобразователя
установлены внутри барабана рядом с каждым потенциометром. Это позволяет
напрямую преобразовывать измеренное аналоговое значение в цифровой сигнал,
который затем передается по шине CAN в центральный блок для обработки.
Каждому датчику длины присваивается уникальный идентификатор, позволяющий
центральному блоку распознавать источник сигнала. Индивидуальная
идентификация датчика достигается путем установки индивидуального кода адреса
для каждой платы аналого-цифрового преобразователя датчика. Кроме того, сигнал
устанавливается на длину мостом (соединительным проводом) на платах аналого-
цифрового преобразователя. Можно найти 120 Ом, установленный между
клеммами 3 и 4 на плате аналого-цифрового преобразователя B, чтобы
предотвратить эхо сигнала, так как это последняя плата в цепи CAN-Bus 2.

A Табличка данных барабана:

2
• Длина 50m
• Контактные кольца 18
• Предварительное натяжение 6
оборотов
• Резервные обороты 2
Потенциометры:
2 x 10 оборотов @ 2,0
3 кОм Поверните
против часовой
стрелки до нуля
B

Legend:
1. Заглушка доступа для регулировки потенциометра См. схему 03011100
2. Привод для обоих потенциометров длины A x B для полной системы
3. Сборка контактного кольца x 18 См. схему 03011072
A. Плата A/D A. Код адреса = 5 для деталей откатного
B. Плата A/D B. Код адреса = D барабана

EKS 4 System 16
 GMK III
Telescope cylinder length sensors
Telescope cylinder length measurement is provided by two potentiometers, which are
fitted inside a recoil drum mounted inside the boom directly under the telescope cylinder
rod anchor point. Two analogue to digital converter boards are mounted within the drum
adjacent to each potentiometer. This allows direct conversion of the measured analogue
value to a digital signal, which is then transmitted via CAN-Bus to the central unit for
processing.

Each length sensor is given a unique identity to enable the central unit to recognize the
source of the signal. Individual sensor identity is achieved by setting an individual
address code to each sensor A/D converter board. Additionally, the signal is set to length
by the bridge (link wire) on the A/D converter boards.

A/D boards under metal covers Bridge

1
A

Drum Data Plate:

• Length 13 metres 2
• Slip rings 26
• Pre-tension 5 turns
• Reserve turns 2 minimum

Potentiometers: 3
Ω
2 x 10 turn @ 2.0 KΩ B
Turn anti-clockwise to zero

Legend:
1. Access plug for potentiometer adjustment. See schematic 03011100
2. Drive for both length potentiometers A & B for complete system
3. Slip ring assembly
A. A/D board A. Address code = 0 See schematic 03011071
B. A/D board B. Address code = 8 for recoil drum details

EKS 4 System 17
 GMK III
Analogue/digital converter boards
Sensors that are potentiometers measuring length or angle values require the measured
value (analogue) to be immediately converted to digital signals for transmission to the
central unit via CAN-Bus. This process is carried out by analogue to digital converter
boards (A/D boards), which are installed either within the aluminum housing box
containing the angle potentiometers or within the recoil drum housings.

All the A/D boards are identical in manufacture and are supplied with a fixed bridge (link
wire) which sets the board to length functions. The board is then configured to suit the
particular application by leaving the bridge for length applications or removing (cutting)
the bridge for angle applications. Setting a unique address (Hex code) for each individual
application then further configures the boards to their specific application.

Configuring the A/D boards in this manner allows the central unit to identify the source of
the measured value and process the information accordingly..

1.28 KΩ

2 1

3 3
To board A

To plug B

Legend:
1. Address switch.
2. Bridge location with bridge (link wire in detail) cut for angle application.
3. Thermal trip fuse @ 300 mA.

See schematic 03011100 for complete system

See schematics 030110701, 030110702 & 03011703 for relevant application
details on units -A111, -A114 & -A110 respectively.

EKS 4 System 18
 GMK III
Analogue / Digital board address codes

Function Unit Identity Board Identity Address code

Main boom A 0
-A110
angle B 8
Main boom A 5
-A114
External length B D
Telescope A 0
-A111
cylinder length B 8
Swingaway A 1
-A210
lattice (PTJ) B A

EKS 4 System 19
 GMK III

Resistor boards
Part of the design criteria for the EKS 4 system is that interconnected components are
continuously monitored for errors. Digital multilevel inputs from proximity switches are all
connected to EKS 4 via resistor boards.

EKS 4 continuously emits a reference voltage through the switched circuits, which is
pulled down to a threshold level by the resistor boards. This threshold level is accepted
by EKS 4 as an open switch (0 volts) due to the software program parameters (fig. 11).

When a digital switch is closed, the switched voltage (24volts) is routed to EKS 4 via the
same resistor board circuit. Due to the additional switched voltage (24 volts) the resistor
board is unable to hold the threshold level. Subsequently, the voltage level rises and is
accepted by EKS 4 as a closed switch due to the software program parameters (fig. 11).

To enable efficient circuit monitoring, the resistor boards are located as close as possible
to the input source (proximity switches).

EKS 4 can detect the following switched input status via resistor boards:

1. Short to ground *0 3 Volts =0

2. Low *3 9 Volts =L
3. Open circuit *9 15 Volts =C
4. High *15 19 Volts =H**
5. Switch closed *19 24 Volts =F**
* These are only typical benchmark values, as they have an upper & lower threshold.
** Both H & F inputs have the same program status = switch closed.

RX1 junction box on tele cyl

24 Volts
8 7 6 5 4 3 2 1

1
24 Volts
2.0 KΩ

1a

8a 7a 6a 5a 4a 3a 2a 1a
EKS 4 X3/X4
Inputs

Figure 11: Actual & schematic view of resistor board principles

EKS 4 System 20
 GMK III
Swingaway lattice (PTJ)
The swingaway lattice is a bi-fold jib (PTJ) that can be mounted on the main boom head.
A hydraulic cylinder controls the jib-offset angle relative to the main boom. Control
signals for the jib cylinder are via the external boom length measuring cable.
o
The hydraulic cylinder can offset the jib to + 40 relative to the main boom, with the top
chord of the 13-metre section being used as the angle reference.

Pressure sensors
Pressure sensors, (transducers) which are installed in the piston and rod side of the jib
cylinder, measure load on the jib. The sensors convert the measured pressure value
internally and transmit the information via CAN-Bus through the external length
measuring cable to the central unit for processing.

CAN-Bus
-A201 piston

2 3
-A203 Rod

Legend:
1. Jib angle sensor & A/D board housing box –A210
2. Piston-side pressure sensor (A) –A201
3. Rod-side pressure sensor (B) –A 203

See schematic 03011100

See schematic 03011094
See electrical group =37/9 for connection details

Figure 12: Actual & schematic view of jib cylinder pressure sensor installation

EKS 4 System 21
 GMK III
Angle sensors
Two angle sensors (potentiometers) are installed on the jib: one to monitor the jib angle
with reference to the horizontal and the other to monitor the offset angle relative to the
main boom. One pendulum driven potentiometer for horizontal measurement is installed
in an aluminum housing box on the left side of the 13-metre section. The other
potentiometer is installed externally on the pivot point of the jib base and the 13-metre
section to measure the offset angle. A mechanical linkage drives this potentiometer.

Angles are initially measured as analogue values and then immediately converted to
digital information for transmission via CAN-Bus to the central unit for processing. To
carry out this task, two analogue/digital converter boards are installed in the housing box
containing the pendulum driven potentiometer on the left side of the 13-metre section
(-A210).

Each angle sensor is given a unique identity to enable the central unit to recognize the
source of the signal. Individual sensor identity is achieved by setting an individual
address code to each sensor A/D converter board. Additionally, the signal is set to angle
by cutting a small bridge (link wire) on the A/D converter boards.

5
1 6

Legend: 4

1. Angle sensor-housing box —A 210

2. Angle sensor (A) = 6.02 KΩ
3. Angle sensor (A) address code 1
4. Angle sensor (B) = 2.0 KΩ (—A 211)
5. Address sensor (A) address code A
6. 120 Ohm resistor, only in board B, to stop signal echo

See schematic 03011100

See schematic 03011094
See Electrical group =37/9

Figure 13: Actual view of jib angle sensor installation

EKS 4 System 22