9.

4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

9.4.1.2 Technical data of the CAN bus

9.4 Communication and control
loops within CAMP The bit rate of CAN signals is 250 kbit/s on CAN
bus 1, 2, and 3. On SAE J1939, the bit rate is
9.4.1 Controller Area Network (CAN) 125 kbit/s.

Each CAN bus is connected with two 120 Ω termi-

CAN is a message-based communication protocol, nating resistors. The terminating resistors are con-
designed specifically for automotive applications. nected in parallel between CAN-High (white cable)
In 1983, CAN was developed by Robert Bosch and CAN-Low (blue cable).
GmbH to reduce the cable harness on vehicles.
1 2 3 4 5 6 7
9.4.1.1 CAN bus systems

The following figure shows an overview of the dif-

ferent CAN bus systems, CAN bus 1 and CAN
bus 2.

642634
Fig. 2 CAN bus system - 642634

1 Terminating resistor in the BCS; 120Ω

2 CAN – participant 1
3 CAN high
4 CAN low
5 CAN – participant 2
6 CAN – participant …
Fig. 1 CAMP main components - 642639
7 Terminating resistor at the drive control
system; 120Ω

1 Hand Levers and Pedals The following figure shows the pin assignment of a
2 Can Bus 2 CAN bus connector.
3 Board Control System (BCS)
4 Can Bus 1
5 Drive Controller Left Hand (DCLH)
6 SAE J1939 Left Hand
7 Left Engine ECM
8 Auxiliary System (AS)
9 Right Engine ECM
10 SAE J1939 Right Hand
11 Drive Controller Right Hand (DCRH)
12 ICN-V
13 Can Bus 3
14 Servo Controller (SC)

The drive controller and the respective engine

communicate via the SAE J1939 protocol over
another CAN bus. The bus systems on either en-
gine power train are identical, except that cables
and connectors on the left power train are marked
with red marks whereas blue marks are used on
the right power train.

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

 The resistance between each of the CAN bus

lines (CAN-High or CAN-Low) and ground (ma-
chine chassis) is very high [MΩ], i. e. open-
circuit operation.
Please note: For resistance check, ignition has
to be off!

1 2 3 4 5 6 7

Fig. 3 CAN bus connector - 642640

1 Shield (metal cable)

2 + 24 VDC (red cable)
3 0 VDC (black cable)
4 CAN-High (white cable)
5 CAN-Low (blue cable)

8 8
9.4.1.3 CAN bus troubleshooting 642638
Fig. 5 Resistance CAN bus line / ground - 642638
In a correctly working CAN bus system on the ex-
cavator, the following rules apply:
 The total resistant of each CAN bus system on 1 Terminating resistor in the BCS; 120Ω
the excavator is about 60 Ω. 2 CAN – participant 1
Please note: For resistance check, ignition has 3 CAN high
to be off! 4 CAN low
5 CAN – participant 2
1 2 3 4 5 6 CAN – participant …
6 7
7 Terminating resistor at the drive control
system; 120Ω
8 Ground

642636
Fig. 4 Total resistant of each CAN bus - 642636

1 Terminating resistor in the BCS; 120Ω

2 CAN – participant 1
3 CAN high
4 CAN low
5 CAN – participant 2
6 CAN – participant …
7 Terminating resistor at the drive control
system; 120Ω

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

Possible error cases for the CAN bus are: 6 CAN – participant …
 One resistor is defective or missing. 7 Terminating resistor at the drive control
In this case, the total resistant of each CAN bus system; 120Ω
system on the excavator is about 120 Ω.

1 2 3 4 5 6 7 Please Note: For resistance check, ignition has to

be off!

9.4.2 Electronic Hydraulic Servo

Control (EHSC)
CAN_High

CAN_Low
Hand levers and pedals are the control units for
the EHSC. The desired operations are detected by
the hand levers and foot pedals and sent to the
Servo Control System (SCS). The components of
the SCS, the Servo Controller (SC) and the ICN-V,
642635 pass the information to the electro-hydraulic pro-
Fig. 6 Resistor missing - 642635 portional valves in the control valve assembly via
PWM signals.
1 Terminating resistor in the BCS; 120Ω
2 CAN – participant 1
3 CAN high
4 CAN low
5 CAN – participant 2
6 CAN – participant …
7 Terminating resistor at the drive control
system; 120Ω

 Three resistors are used in the CAN bus sys-

tem.
In this case, the total resistant of each CAN bus
system on the excavator is about 40 Ω.
Fig. 8 Overview EHSC - 642940
1 2 3 4 5 6 7
1 Hand levers and foot pedals
2 CAN Bus
3 Servo controller / ICN-V
4 Harness tree
5 Switch cabinet X24
6 Proportional valve current 70 – 650 mA;
maximum value might be reduced for
specific functions such as clam close.
7 Proportional valve

642633 Depending on the positions of the hand lever and

Fig. 7 Three resistors - 642633
foot pedal, the main pump flow is adjusted. Load-
limit regulation monitors the resulting load of the
engine and avoids overload situations.
1 Terminating resistor in the BCS; 120Ω
2 CAN – participant 1 For detailed information see chapter “Hydraulic
3 CAN high System”.
4 CAN low
5 CAN – participant 2

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

9.4.2.1 Proportional valve block o Boom FS lower

o Rod Side BH
The servo controller communicates with the pro- o Rod Side FS
portional valve block via Pulse-Width Modulation 5: -2Y4 Float Valve Boom
(PWM) signals. o Float Valve Boom
o Float Valve BH
o Float Valve FS
6: -2Y5 Boom BH hoist
o Boom FS hoist
o Piston Side BH
o Piston Side FS
7: -2Y6 Stick BH in
o Stick FS in
o Piston Side BH
o Rod Side FS
8: -2Y16 Swing right BH
o Swing right FS
o Bal. Valve BH
o Bal. Valve FS
9: -2Y15 Swing left BH
o Swing left FS
Fig. 9 Proportional valve control - 642941 o Bal. Valve BH
o Bal. Valve FS
1 Controller 10: -2Y8 Stick BH out
2 Junction box o Stick FS out
3 Wire o Rod Side BH
4 Proportional valve o Piston Side FS
11: -2Y7 BH no Function
o Stick FS Float Valve
The functions and valves of the proportional valve o BH no Function
block are assigned as shown in the figure below. o Float Valve FS
12: -2Y14 Travel left for.
o Travel left for.
o Travel Valve
o Travel Valve
13: -2Y13 Travel left backward
o Travel left backward
o Travel Valve
o Travel Valve
14: -2Y12 Travel right for.
o Travel right for.
o Travel Valve
o Travel Valve
15: -2Y11 Travel right backward
o Travel right backward
Fig. 10 Proportional valve block - 642942 o Travel Valve
o Travel Valve
16: -2Y10 BH no Function
1: -2Y18 Switch-on Valve Servo on
o Clam FS close
2: -2Y1 Bucket BH fill
o BH no Function
o Bucket FS fill curl in
o Piston Side FS
o Piston Side BH
17: -2Y9 BH no Function
o Piston Side FS
o Clam FS open
3: -2Y2 Bucket BH empty
o BH no Function
o Bucket FS empty curl out
o Rod Side FS
o Rod Side BH
18: -2Y20 Switch-on Valve Track Tension
o Rod Side FS
4: -2Y3 Boom BH lower

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

9.4.3 Hand Levers and Pedals

For information on navigating the machine via

hand levers and control pedals see “Operating
Instructions”.

9.4.3.1 Installing and removing

Preparing the installation:

 Switch off the engines.
 Switch off the ignition.
 Switch off the battery main switch and secure it
with a padlock against unintended restart.

Removing the hand lever:

Fig. 12 Hand lever connector - 642944

 Disconnect the cable from the hand lever.

Installing the controller:

 Install it in reverse order of the de-installation.

Completing the installation:

 Restart the machine.

9.4.3.2 Settings

Fig. 11 Removing the hand lever - 642943

 Remove the four screws (see circles).

 Carefully move the hand lever up and out (2).

Fig. 13 Hand lever settings - 642945

Address Table Hand Lever / Foot Pedals

Control Unit Address

Left Hand Lever 0
Right Hand Lever 1
Foot Pedal Left 2
Foot Pedal Middle 3
Foot Pedal Right 4

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

9.4.4 Pump flow regulation

Each drive controller, DCLH and DCRH, regulates

the pump flow of the respective engine power train.
By regulating the pump flow, the drive controller
prevents overloading the engine.
The pump flow regulation is required as the exca-
vator’s maximum hydraulic power is larger than the
engine’s maximum power.

The regulation works as follows:

 The drive controller monitors the engine’s RPM.
 If the engine’s RPM is too low, the drive control-
ler initiates a reduction of the amount of oil in
the main pump hydraulic circuit.
 As a consequence of this reduction, the en- Fig. 14 Pump flow regulation - 642946
gine’s RPM will rise again.
 Then, the drive controller initiates an increase
of the amount of oil in the main pump hydraulic 1 Acceleration 0 - 100%; hand levers and
circuit. foot pedals
2 Signal via CAN bus
For detailed information on the pump flow regula- 3 Proportional valve block
tion mechanism, see chapter “Hydraulic system”. 4 Servo controller
5 Pump requirements from servo controller
via CAN bus
9.4.4.1 Overview pump control 6 Engine load
7 Engine temperature
By acceleration of hand levers and/or foot pedals 8 Hydraulic oil temperature
(1) a signal is generated that is sent to the servo 9 Intake manifold temperature
controller (4) via CAN-Bus. 10 Drive controller
Based on this signal, the servo controller sends the 11 Pump control current (150 – 850mA)
pump requirements (5) via CAN bus to the drive 12 Main pump (variable angle 0 – 15°)
controller (10). 13 Pump control pressure (5 - 43bar)
The drive controller sends the pump control current 14 Servo pressure
(11) to the proportional valve. Based on this cur-
rent, the proportional valve generates the required
pump control pressure (13) to change the angle of
the main pump (12). This causes the change of 9.4.4.2 Data transfer
their oil delivery rate.
The SAE J1939 BUS transfers data between the
For controlling the main pumps, the drive controller drive controller and the engine ECM such as:
takes into account:  engine oil pressure
 Pump requirements from servo controller  speed signal
 engine load  cooling water temperature
 engine temperature  speed adjusting signal
 hydraulic oil temperature
 intake manifold temperature 9.4.4.3 Reducing the Pump Control current /
pressure

The Pump Control current / pressure is reduced if

one of the following conditions is true:
 intake manifold temperature exceeds 83 °C
 engine coolant temperature exceeds 100 °C
 hydraulic oil temperature exceeds 80 °C

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

Fig. 16 Proportional valve control - 642948

Fig. 15 Reducing PMS current / pressure - 642947

1 Sensor – Hydraulic oil temperature

1 Acceleration 0 - 100%; hand levers and
2 Drive controller
foot pedals
3 Variable displacement oil cooling fan
2 Servo controller
pump
3 Intake manifold temperature exceeds
4 Fan oil cooling system
83 °C
5 Hydraulic oil temperature
4 Engine coolant temperature exceeds
6 High speed level fan (60°C)
100 °C
7 Low speed level fan (50°C)
5 Hydraulic oil temperature exceeds
8 Controller output current 50 – 650 mA
80 °C
6 Drive controller
7 Valve
8 Pump requirements from servo controller 9.4.4.5 Overview engine cooling
via CAN bus
9 Signal via CAN bus drive controller The engine (1) sends the following information to
the drive controller (4) via SAE J1939 bus:
 engine coolant temperature
9.4.4.4 Overview hydraulic oil cooling  intake manifold temperature

The temperature of the hydraulic oil is monitored Based on the data received from the engine, the
by a temperature sensor (1). Based on the data drive controller triggers the engine cooling pump
received from the temperature sensors, the drive (5) to run the fan of the engine water cooler system
controller (2) triggers the oil cooling fan pump (3) (6).
to run the fan of the oil cooling fan system (4). Due to fail safe reasons, a low controller output
Due to fail safe reasons, a low controller output current (10) is equivalent to a high speed level of
current (8) is equivalent to a high speed level of the fan (8).
the fan (6).

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

9.4.5 Lubrication system

The Auxiliary system controls the greasing system

and the boarding and maintenance lights.

For detailed information on the lubrication system

see chapter “Central lubrication system”.

9.4.5.1 Lubrication system upper carriage

The machine is equipped with a two-line lubrication

system (line A and B). The lines are lubricated
alternately.
Fig. 17 Overview Engine cooling - 642949
The following figure shows the basic components
that control the greasing system of the upper car-
1 Engine riage.
2 Engine coolant temperature via SAE
J1939
3 Intake manifold temperature via SAE
J1939
4 Drive controller
5 Variable displacement of engine cooling
pump
6 Fan engine cooler
7 Temperature
8 High speed level fan
o Blue: Engine coolant 99°C
o Magenta: Intake manifold 62°C

9 Low speed level fan

o Engine coolant 89°C
o Intake manifold 56°C
10 Controller output current
Fig. 18 Lubrication sensors - 642950

-5Y3 Unloader valve upper carriage

-5B6 Lube pressure monitoring upper carriage
-5Y1 On/Off Grease pump upper carriage
-5Y2 Switch over valve A-B upper carriage
-5B4 Contamination monitoring greasing
pump

The two sensors -5B2 and -5B3 (line A and B)

detect whether grease reaches the grease distribu-
tor at the stick as this grease distributor is in a
protected area and further away from the grease
control panel than any other grease distributor.

A lubrication cycle consists of lubrication in line A

and line B. The lubrication cycle has been com-
pleted properly if all of the following conditions are
true:
 Sensors -5B2 and -5B3 have detected that the
grease has reached the grease distributor.

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

 Sensor -5B6 has detected that the predefined If the grease pump starts to work, the pressure has
lubrication pressure has been reached. to reach the lower switch point pressure at the
pressure sensor -5B7 within a predefined time.
If the lower switch point pressure has been
reached, the superior switch point pressure has to
be reached within a predefined time. If the pres-
sure increases too slowly, a leakage might be the
reason.
If the superior switch point pressure is reached, the
lubrication is completed. The lubrication system is
switched off and the pressure has to fall to the
lower switch point pressure within a predefined
time.

Fig. 19 Proximity switch lubrication - 642951

A fault message is triggered as soon as the lubri-

cation process for one of the two lines exceeds the
maximum lubrication time.

The following figure explains the lubrication cycle.

Fig. 21 Lubrication cycle under carriage - 642953

9.4.6 Lights

The auxiliary controller controls all of the following:

 Lighting Operators Cab
 Lighting Ladder
 Maintenance Light

The time delay for the lighting of the ladder is op-

erator-configurable.
Fig. 20 Lubrication cycle upper carriage - 642952

9.4.5.2 Lubrication system of the under car-

riage

The lubrication system of the under carriage con-

sists of a single-line system. Grease is pressed
into the rollers.

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9.4 COMMUNICATION AND CONTROL LOOPS WITHIN CAMP

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