KUKA KR C2 edition2005 Robot Controller Operation Manual

Deep analysis of KUKA KR C2 robot controller: perfect integration of modular design and safety technology

Introduction: Control Center of Industrial Robots

In the field of industrial automation, robot controllers play the role of the "brain", responsible for handling all motion planning, safety monitoring, and human-computer interaction tasks. KUKA KR C2 edition 2005, as the core control unit of the KUKA robot series, has been widely used in various industrial fields such as automotive manufacturing, metal processing, logistics and handling due to its modular design and highly integrated safety system.

This article is based on the official technical documentation of KUKA, providing a comprehensive technical reference for industrial robot system integrators, maintenance engineers, and technical enthusiasts by deeply analyzing the system architecture, core components, safety mechanisms, and maintenance diagnostic methods of the KR C2 robot controller.

Chapter 1: Overview and Architecture Design of KR C2 System

1.1 Composition of Industrial Robots

A complete KUKA industrial robot system consists of the following core components:

Mechanical arm: The mechanical body of a robot, which includes 6 or more motion axes

Robot controller: KR C2 control cabinet, responsible for motion control and system coordination

Teaching pendant (KCP): human-computer interaction interface used for programming and operation

Connecting cables: power cable and data cable

Software system: KUKA system software (KSS) and various process software packages

Optional peripherals: external axis (linear slide table, positioner), process equipment, etc

1.2 Modular architecture of KR C2 controller

The design concept of KR C2 robot controller fully embodies the modular idea, and the entire system can be divided into the following main parts:

Control PC Unit: Based on industrial PC architecture, running Windows operating system and real-time extension VxWorks, providing human-machine interface, program management, and network communication functions. Control the PC to be equipped with a dedicated motherboard, processor, at least 512MB of memory, and partitioned hard disk (C: system disk, D: data disk).

Power supply unit: including power module, servo drive module, fuse element, and cooling fan. The KPS600 main power supply provides DC bus voltage for the entire system, while the KPS-27 low-voltage power supply provides 24V control voltage.

Safety Logic ESC: A dual channel computer-aided safety system that monitors all safety related components in real time and immediately cuts off the drive power once a fault is detected.

KCP teaching pendant: Integrated with mode selection switch, enable switch, emergency stop button, and 6D mouse, it is the core interface for interaction between operators and robots.

Connection panel: It integrates power input, motor power output, data communication, and user I/O interfaces.

The advantages brought by this modular architecture are obvious: during fault diagnosis, the problem module can be quickly located, during maintenance, only the faulty component needs to be replaced without disassembling the entire system, and corresponding functional cards can be added according to the needs during system expansion.

Chapter 2: Deep Analysis of Control PC Core Components

2.1 Industrial grade PC platform

The control PC of KR C2 adopts an industrial grade motherboard, which integrates a processor, memory slot, network card, and BIOS system. It is particularly noteworthy that KUKA has conducted strict testing and optimization on the motherboard configuration, and users who modify the configuration themselves may cause system instability or even failure.

The motherboard integrates a variety of peripheral interfaces:

2 USB ports (for program backup and system maintenance)

2 serial interfaces (COM1 for mouse, COM2 backup)

1 parallel interface (for printers or encryption dongles)

1 Ethernet interface (for network integration)

6 PCI slots and 1 AGP PRO slot

2.2 MFC3 multifunctional card: the central nervous system of the system

MFC3 is one of the most critical expansion cards in KR C2, which can be divided into standard and technical versions according to application requirements:

MFC3 Standard Edition Core Features:

RTAcc real-time processing chip, supporting VxWin RT real-time operating system

DeviceNet main station interface, connecting field devices

DSE interface, supports up to 2 DSE-IBS-C33 modules

CI3 Security Logic Interface

Fan monitoring function

MFC3 Technical Edition Enhanced Features:

Includes all features of the standard version

CR option (RoboTeam) interface

SafeRobot Safety Interface

Need to be used in conjunction with CI3 Tech board

The two dual color LEDs on the MFC3 card provide real-time indication of the data communication status of the DeviceNet CAN bus, providing intuitive basis for fieldbus fault diagnosis.

2.3 DSE-IBS-C33: Servo driven bridge

The DSE-IBS-C33 module serves as an additional board for MFC3, responsible for controlling the servo module and processing error and status information read from the servo module. When the robot system needs to control more than 8 axes, an additional DSE-IBS-C33-AUX expansion board must be installed.

The green LED on the module visually displays the working status: the LED flashes during normal operation, and turns off or stays on when there is a communication failure. The DSE-RDW diagnostic tool allows for in-depth analysis of the communication quality between DSE and RDC.

2.4 KVGA graphics card: KCP's visual channel

The KVGA card is specifically designed to connect KCP teaching devices and supports parallel operation of external VGA displays. There are two KCP connection ports on the card, and the resolution and color count (16 colors or 256 colors) are automatically configured during system installation. This design allows for the simultaneous use of a teaching pendant and an external display during the debugging phase, greatly facilitating system maintenance.

Chapter 3: RDC/SafeRDC Analysis Techniques

3.1 Working principle of rotary digital converter (RDC)

RDC (Resolving Digital Converter) is installed in the RDC box of the robot base and is a key component for achieving precise position control. Its core functions include:

Provide excitation power for a rotating transformer with 8 axes

Provide isolated power supply for 8 motor temperature sensors (KTY84)

Convert analog signals to digital signals

Automatically perform offset and symmetry adjustment

Monitoring the open circuit fault of the rotary transformer circuit

Monitor motor temperature

Communicate with DSE-IBS3 through RS422 serial interface

The RDC board stores important data: runtime counter, absolute position, rotation position, and adjustment data (offset, symmetry). This means that after replacing the RDC, it is necessary to perform offset and symmetry adjustments again.

3.2 SafeRDC: Safety level location monitoring

SafeRDC is a security enhanced version of RDC, consisting of a SafeRDC board, an I/O Print board, and a security shell, suitable for application scenarios that require higher levels of security:

SafeRDC core functions:

Redundant evaluation of rotary signals

Monitor the position of the robot based on the set safety parameters

Monitoring the dual channel operation status of secure input and output

Actual location of safety assessment

Safely cut off the drive power supply

Communicate with the robot controller

Safe Input/Output Pulse Test

SafeRDC meets the safety requirements of ISO 13849-1 PL d level through hardware redundancy and self checking mechanism. Its onboard LED indicator system provides detailed status information to help maintenance personnel quickly diagnose faults.

3.3 Quick measurement function (option)

The rapid measurement function records robot position data through high-speed measurement input and digital sensors for measuring workpieces and subsequent calibration applications. This feature supports two modes of internal power supply (via RDC) and external power supply:

Single RDC configuration: 5 measurement inputs directly connected to X33 interface

Dual RDC configuration: requires special wiring to connect two RDC boxes in series

For the SafeRDC version, the X33 interface provides 7 pins, including 5 measurement inputs,+24V internal power supply and GND, and 0V internal reference voltage.

Chapter 4: ESC Safety Logic System

4.1 Dual channel security architecture

ESC (Electronic Safety Circuit) is the safety core of KR C2, which adopts dual channel computer-aided design and permanently monitors all safety related components. Once the safety circuit malfunctions or is interrupted, the system immediately cuts off the driving power supply, causing the robot to stop moving.

Key input signals monitored by ESC system:

Local emergency stop (emergency stop button on KCP)

External emergency stop (connected through customer interface)

Operator protection (safety door switch)

Enable switch (three-level switch on the back of KCP)

Drive off/on button

Operation mode selection (T1, T2, AUT, AUT EXT)

Verify Input (QE)

Output status monitored by ESC system:

Operation mode indication

Drive on status

Local emergency stop status

4.2 CI3 series interface board

The CI3 board connects various nodes of the ESC system to the customer interface, and there are four versions according to application requirements:

CI3 standard board: No independent nodes, connected to various nodes in the ESC circuit, indicating local emergency stop status through relays, and resetting the ESC circuit through the reset button.

CI3 expansion board: With independent nodes, it can display operation mode, drive on and local emergency stop status, and is equipped with multiple relay outputs.

CI3 bus board: Connect the ESC circuit to PILZ's safety bus system through the SafetyBUS gateway board, suitable for complex safety network integration.

CI3 Tech board: has independent nodes, supports KUKA. RoboTeam, KUKA. SafeRobobot, SafetyBUS gateway, and external axis control, and must be used in conjunction with MFC3 Tech card.

4.3 Safety Features and Stop Response

The ESC system triggers different types of stop responses based on different triggering conditions:

Trigger conditions T1/T2 mode AUT/AUT EXT mode

Safety door open - STOP 1

Emergency stop press STOP 0 STOP 1

Enable the switch to release STOP 0-

Press the start button to release STOP 2-

Drive shutdown button STOP 0 STOP 0

STOP key STOP 2 STOP 2

Operation mode switch STOP 0 STOP 0

STOP 0: Immediately cut off the drive power and apply the mechanical brake

STOP 1: Maintain path braking, cut off drive power after 1 second

STOP 2: Normal deceleration stops, drive remains powered on

Chapter 5: KUKA Servo Drive System

5.1 KPS600 power supply unit

KPS600 is the main power module of KR C2, integrating multiple functions:

Rectification circuit: converts three-phase AC power into DC bus voltage

Charging circuit: Control the pre charging process of DC bus capacitor

Braking circuit: consumes regenerative energy to prevent bus overvoltage

Discharge circuit: Quickly discharge after shutdown to ensure safe maintenance

Main contactor K1: controls the on/off of the main power supply

KPS600 provides multiple 24V power supplies, which respectively supply power to the DC/DC converters of the motor brake, customer interface, control PC, and servo drive module. The 6 LED indicator lights on the panel display the working status and fault codes in real time:

LED1 (red) and LED2 (green) combined display processor status, bus voltage, communication errors, etc

LED3 and LED4 indicate emergency stop status

LED5 indicates the braking status of the robot

LED6 indicates the external shaft brake status

5.2 KSD servo drive module

The KSD module is divided into two size series based on current capacity: BG1 (KSD-08/16/32) and BG2 (KSD-48/64). Each KSD integrates:

Power output stage

current regulator

Interbus driver bus interface

Motor current monitoring and short-circuit protection

Temperature monitoring of radiator

Communication monitoring

The two LEDs (red/green) on the module provide rich status information: from power loss to overcurrent faults, from bus undervoltage to servo enable, maintenance personnel can quickly determine the type of fault by observing the LED status.

5.3 Dual loop cooling system

KR C2 adopts an innovative dual loop cooling design, significantly improving the thermal stability and lifespan of the system:

Internal cooling circuit: using a heat exchanger to cool and control the electronic component area, keeping sensitive components operating within a suitable temperature range.

External cooling circuit: Directly cool the brake resistor, servo module, and KPS radiator with ambient air, and these high heat generating components directly exchange heat with the outside world.

The key to this design is to prohibit the installation of filter cotton at the air inlet, otherwise it will cause an increase in internal temperature and shorten the service life of the equipment!

Chapter 6: Detailed Explanation of KCP Teaching Device

6.1 Human Computer Interaction Design

As the core device for operator robot interaction, KCP (KUKA Control Panel) is designed with full consideration for operational convenience and safety

Front panel layout:

Mode selection switch: With a removable key, the operating mode cannot be changed after locking

6D Space Mouse: Intuitively Control Robot Motion

Emergency stop button: Mushroom head red button

Drive on/off button

Numerical keypad and function soft keys

Start/Stop/Back button

8-inch VGA display screen (640 × 480 resolution)

Back panel design:

Three three-level enable switches (position 1: not pressed, position 2: middle position, position 3: panic position)

Start button (physical redundancy)

nameplate label

6.2 Safety Logic of Enabling Switches

The design of the enable switch embodies the perfect combination of ergonomics and safety engineering:

In T1 (manual slow) and T2 (manual fast) modes, the operator must keep the enable switch in the middle position (position 2) to drive the robot. If the switch is fully released (position 1) or pressed firmly to the bottom (position 3-panic), the system immediately executes STOP 0 to stop and cut off the drive power.

This three-level design ensures that the robot can safely stop in any unexpected situation (such as the operator falling due to nervousness, losing consciousness, being forced to let go, etc.). KUKA explicitly warns: Do not use tape or other methods to fix the enable switch!

6.3 Operating Mode and Application Scenarios

KR C2 supports four operating modes, each corresponding to specific application scenarios and security requirements:

T1 (manual slow speed):

Maximum speed 250mm/s

Used for programming, teaching, and program testing

Enable switch is valid, safety door is invalid

T2 (manual quick):

Capable of programming speed (exceeding 250mm/s)

Only used for program verification, not programmable

The operator must be outside the safe area

AUT (Automatic):

No superior controller, independent operation

It is necessary to connect the safety circuit

Cannot be manually operated

AUT EXT (External Automatic):

Controlled by higher-level controllers such as PLC

It is necessary to connect the safety circuit

Used for production line integration

Chapter 7: Installation Planning and Electrical Connections

7.1 Installation conditions and space requirements

The installation of KR C2 must meet strict space requirements:

Minimum gap requirement:

Left/Right: 50mm (when installed side by side)

Rear: 50mm

Front: Door opening space (approximately 180 ° for independent cabinets and 155 ° for side-by-side cabinets)

Top: If there is a top cabinet, additional space is required

Environmental conditions:

Operating temperature:+5 ° C to+45 ° C (without cooling unit),+5 ° C to+55 ° C (with cooling unit)

Storage temperature: -25 ° C to+70 ° C (without battery), -25 ° C to+40 ° C (with battery)

Humidity level: 3k3 per DIN EN 60721-3-3

Altitude: No derating required below 1000m, derating reduced by 5% for every 1000m below 4000m

7.2 Power Connection Requirements

KR C2 has strict requirements for power quality:

Electrical parameters:

Rated voltage: AC 3 × 400V to 3 × 415V

Voltage tolerance: 400V -10% to 415V+10%

Grid frequency: 49 to 61Hz

System impedance: ≤ 300m Ω

Rated power: Standard 7.3kVA, Heavy duty robot 13.5kVA

Fuse specifications: minimum 3 × 25A slow melting, maximum 3 × 32A slow melting

Important precautions:

Must be connected to the TN system (neutral point grounded)

It is necessary to rotate the magnetic field clockwise to ensure that the fan rotates correctly

System impedance exceeding 300m Ω may cause the fuse to fail to melt in a timely manner during ground faults

7.3 X11 Interface Configuration

X11 is a 108 pin Harting connector used to connect external security devices, and its correct configuration directly affects the security of the entire system

Key signal:

Drive open channel A/B (pins 11/12): Floating point contact, indicating the status of the drive contactor

Automatic mode contact (pin 48/46): Closed in automatic mode

Test mode contacts (pins 48/47): Closed during test mode

Verify input channels A/B (pins 50/51): STOP 0 triggered in all modes

If verification input is not used, pin 50 must be short circuited to test output 38, and pin 51 must be short circuited to test output 39, otherwise the system cannot operate.

Chapter 8: Maintenance and Fault Diagnosis

8.1 Preventive Maintenance Plan

The maintenance work of KR C2 must be carried out according to strict cycles:

Every 6 months:

Test the emergency stop button function

Test mode selection switch function

Check the direction of the external fan

Every 12 months:

Clean the interior of the control cabinet

Check and tighten all wiring terminals

Replace PC fan (based on running time)

Every 2 years:

Replace the control PC battery

Check the status of the pressure compensation plug

Every 5 years:

Replace the internal battery of KPS600

Replace the safety bus I/O terminal (safety bus system)

Regularly charge according to storage temperature:

≤ 20 ° C: Charge once every 9 months

20 ° C to 30 ° C: Charge every 6 months

30 ° C to 40 ° C: Charge every 3 months

8.2 LED Fault Diagnosis Guide

The LED indicator lights of each module in KR C2 provide first-hand information for rapid fault diagnosis:

KPS600 LED combination indicator:

LED1 flashes 5 times/1.5Hz: abnormal brake resistor current

LED1 flashes 4 times/1.5Hz: brake resistor fault

LED1 flashes 3 times/1.5Hz: DC bus overvoltage

LED1 flashes twice/1.5Hz: internal/radiator overheating

LED1 flashes once/1.5Hz: 24V power failure

KSD LED status:

Green constantly on: servo enabled, working normally

Green flashing: DC bus undervoltage (<250V)

Red flashing: Fault state (bus overvoltage)

Red green flashing: Communication error

CI3 board LED monitoring:

By monitoring the status of LED16-LED28, it is possible to monitor the 24V power supply, 5V ESC node, communication status of each node, and fuse status.

8.3 DSE-RDW diagnostic tool

DSE-RDW is a professional diagnostic tool provided by KUKA, which can deeply analyze the communication status between DSE and RDC:

Core diagnostic function:

Display DSE working status and DPRAM test results

RDC table displays measurement and configuration data for all axes

Communication error counter monitors transmission quality

Automatic adjustment of offset and symmetry

When the communication error counter continues to increase, it indicates interference in the connection between DSE and RDC, which may be due to poor cable shielding, poor contact, or EMC issues.

8.4 ESC Diagnostic System

The ESC diagnostic tool provides status monitoring and fault analysis functions for safety circuits:

Node status display:

Real time display of the status of each ESC node (CI3, KCP, KPS, MFC)

Dual channel signal consistency monitoring

Input/output signal level display

Fault record:

The error log is saved in C:  KRC  Robotter  Log  EscDiagnosis.rog

Record timestamps for all security related events

Support detailed configuration in expert mode

When a 'crossed connection error' occurs, it indicates that the A/B channels of the input signal are reversed or short circuited with the test pulse output, which is the most common wiring error in safety circuits.

Chapter 9: Safety Philosophy and Operating Standards

9.1 Risk assessment and protective measures

The security concept of KR C2 is based on a comprehensive risk assessment:

Definition of Hazardous Areas:

Workplace: Normal range of motion for robots

Dangerous area: workspace+stopping distance

Safe Zone: Outside the Dangerous Zone

Classification of protective measures:

Intrinsic safety design: mechanical limit, software limit

Protective devices: safety fence, grating, safety door

Warning devices: warning lights, buzzers, signs

Organizational measures: operating procedures, training, authorization

9.2 Verification testing of security functions

After each re debugging, all security features must be verified:

Test project:

Local emergency stop function (press emergency stop → STOP 0/1)

External emergency stop function (disconnect external contacts → STOP 1)

Enable switch function (release middle position → STOP 0)

Safety door function (open door → STOP 1)

Verify input function (disconnect QE → STOP 0)

T1 speed verification:

Programming a maximum speed linear trajectory

Calculate trajectory length

Run at 100% magnification in T1 mode and time with a stopwatch

Calculate actual speed not exceeding 250mm/s

9.3 Network Security and Antivirus

With the development of Industry 4.0, the network security of robot controllers is becoming increasingly important

KUKA recommends security measures:

When integrating the controller into the company network, a firewall must be installed

Regularly update the virus database and perform virus scans

Change the default passwords for "Expert" and "Administrator"

Only authorized personnel are aware of the password

Security update information can be found at www.kuka.com

9.4 Safety measures for single point control

When using the Submit interpreter, PLC, OPC server, or remote maintenance tool, it is necessary to pay attention to the principle of "single point control":

Potential risks:

Submit interpreter can modify robot motion in T1/T2 mode

OPC servers can modify programs or outputs without being detected

External keyboard and mouse can modify parameters without the operator's knowledge

Protective measures:

Do not use Submit interpreter or PLC to modify safety related signals

OPC server is only used for diagnosis and visualization, not for parameter modification

When using KCP, unplug the external keyboard and mouse