Fault Simulation

The SCALEXIO FIU concept with an example selection of HighFlex I/O boards.

Fault simulation lets you insert faults, such as broken wires and short circuits, on the electrical level. For fault simulation, dSPACE provides an integrated solution on the SCALEXIO HighFlex I/O boards and the MultiCompact I/O unit. Additionally, customized rack systems can be equipped with special fault simulation solutions to provide higher currents or more fail rails.

Hardware Components

The SCALEXIO Failure Insertion Unit (FIU) consists of several components:

  • An onboard failure routing unit (FRU) on the I/O channels prepares fault simulation by switching the I/O channels to failrails. The FRU is available for each channel on the MultiCompact and HighFlex boards and uses relays to provide the features of the central failure simulation unit to each channel.
  • Depending on their properties, the channels are connected to the failure simulation system by the high-current (up to 80 A) or the low-capacitance (up to 1 A) failrail. The low-capacitance failrail for an optimized signal quality connects signal generation channels and bus channels to the central FIU. The high-current failrail connects signal measurement channels to the central FIU.
  • The central FIU is located on either the DS2642 FIU & Power Switch Board or the DS2680 I/O Unit. The central FIU uses semiconductor switches for switching the faults. It switches very fast, which makes it possible to simulate loose contacts or insert faults for a very precise duration.
  • The failrail segment switch is used to switch selected segments into the failrails for fault simulation. This way, the conducting capacity can be minimized to avoid signal corruption, even for large simulation systems that have a high number of inputs/outputs or that are distributed across several cabinets.

Fault Type Fault on Single Signals Fault on Several Signals
Open circuit 1 channel All channels1)
Short circuit to ground or UBAT 1 channel Up to 10 channels1) 2)
Short between channels 2 channels Up to 10 channels1) 2)
Fault with pulsed switching Yes No

1) Requires the option “Activation by FRU relay” and is only possible on I/O channels without current enhancement.
2) Depending on the ampacity of the failrail.

License Concept

The SCALEXIO HighFlex and MultiCompact boards include a fault simulation (FS) function. You need an additional FS license to activate the fault simulation. The FS license will be checked at the host PC. Each license can be used for one SCALEXIO system. The licenses are scaled for fault simulation with different numbers of I/O channels capable of fault simulations. The fault simulation is configured in ConfigurationDesk, so you need the appropriate SCALEXIO Failure Simulation license for the number of I/O functions that are mapped to channels with an FRU that you use in your real-time application. The FS license is needed only for running the simulation, not for configuring the I/O channels with ConfigurationDesk.

Tracing FIU States

The diagnostic functions of ECUs have to detect each fault within a specified time. To help test an ECU’s diagnostic functions, SCALEXIO provides FIU state tracing. This enables you to measure or plot FIU states and therefore to monitor the time from a change in FIU state to any other event, such as the detection of the fault.

Faults on Multiple Signals

SCALEXIO supports the simultaneous insertion of multiple faults during simulation to allow fault classes such as broken wire, short circuit to ground or UBAT, or short between channels. This function can be enabled in ConfigurationDesk for channels without current enhancement.

Additional Fault Insertion Units for Customized Systems

For the customized system, additional types of fault simulation are available in addition to SCALEXIO Fault Simulation. This enables you to tailor the system to your project-specific requirements. The fault simulation for customized sytems can be remotely controlled with the ControlDesk Failure Simulation Module or, optionally, with AutomationDesk.

Fault Simulation Variant 1

Variant 1 for fault simulation on SCALEXIO supports fault simulation on all ECU input and output pins. All digital and analog I/O boards from dSPACE can be used for fault simulation. The relay boards (DS291) for fault simulation can be used on their own for fault simulation on sensor signals (ECU inputs) or in conjunction with load boards (DS281) on actuator signals (ECU outputs). Fault relays are controlled via a serial RS232.

Fault Simulation Variant 2

The second fault simulation variant uses a central relay switching matrix (DS293) for fault simulation on ECU inputs and outputs. Five different system potentials (for example, Terminal 30, Terminal 31, Terminal 15) can be switched on three different rails via load modules (DS282). Further devices that can be connected, including various measurement devices (Meas0-4), an electronic source (Source), and Rsim modules for transition impedance. Fault simulation is controlled via a CAN interface.

High-Current Fault Simulation

The high-current fault simulation unit on SCALEXIO supports fault simulation on ECU inputs and outputs. One FIU controller card (DS5355) supports up to 19 signal channels on two high-current FIU relay trays (DS5390). Due to its modularity, the FIU controller card can be expanded to increase the number of channels. These relay trays allow for faults with currents up to 50 A and voltages of up to 300 V. The FIU is controlled from ControlDesk via a serial RS232 or CAN.

Customized Interfaces to Diagnostic and Calibration Hardware

Many companies already have their own diagnostic and calibration hardware to perform tasks such as reading out internal ECU variables from the fault memory. If you want to use your own diagnostic and calibration hardware, a special interface for SCALEXIO is needed, which, in some cases, might require engineering. You can connect any kind of measuring device, digital scope, and diagnostic device you like with special protocols such as GPIB or RS232.

Real System Components

In some cases, the real system components (such as injection valves, hydraulic components, and sensors) have to be integrated into SCALEXIO. This is necessary, for example, if components for the same ECU are provided by different suppliers and have to be checked together with the ECU within the simulated environment. Moreover, not every vehicle component can be simulated accurately enough with a justifiable amount of time and money. Some ECUs require real loads at their outputs to function.

Other Hardware Components

  • Optional inclusion of third-party hardware, e.g., load panels, signal routing units, GPIB instruments
  • Power switch modules

CAN Gateway

CAN gateway for simulating errors in large ECU networks.

In large-scale CAN networks, testing bus communication plays a key role. Engineers need to test the behavior of ECUs and distributed functions if an expected CAN message fails to arrive or contains unexpected signals. To simulate faults, a CAN gateway module is inserted into the CAN network (see illustration). Each ECU can be connected individually to one of the two CAN controllers in the dSPACE Simulator. Signal manipulation via software allows you to change any CAN messages from any ECU to achieve a predefined effect on the other ECUs in the CAN network. The CAN software (dSPACE Bus Manager) offers a wide range of typical error situations right up to the message or individual signal level.


Feature SCALEXIO FIU SCALEXIO Customized Rack Systems Variant 1 SCALEXIO Customized Rack Systems Variant 2 SCALEXIO Customized Rack Systems High-Current
General Integrated with SCALEXIO MultiCompact I/O units and HighFlex boards
  • Available with SCALEXIO customized rack systems
  • Engineering needed
  • Available with SCALEXIO customized rack systems
  • Engineering needed
  • Available with SCALEXIO customized rack systems
  • Engineering needed
I/O boards with integrated FIU
  • DS2601
  • DS2621
  • DS2671
  • DS2672
  • DS2680
  • DS2690
DS291 DS282 DS5355/DS5390
Number of cards per simulator Via the I/O boards Configurable Configurable Configurable
Number of channels per card Depends on I/O board 10 10 Up to 9
Switch type
  • Relay
  • Central module with semiconductor switch
Relay Relay Relay
Central modules
  • DS2642
  • DS2680
- 1 x DS293 -
Max. continuous current Up to 80 A (depends on I/O board) 8 A 8 A 50 A

Possible fault types SCALEXIO FIU SCALEXIO Customized Rack Systems Variant 1 SCALEXIO Customized Rack Systems Variant 2 SCALEXIO Customized Rack Systems High-Current
Broken wire Included Included Included Included
Short circuit to ground Up to 10 channels Included Included Included
Short circuit to battery voltage Up to 10 channels Included Included Included
Short circuit to another ECU pin via common failrail Up to 10 channels Included Included Included
Broken wire with additional hardware (Rsim, Meas or Source) in series Not available Not available Included Not available
Short circuit to another ECU pin via additional hardware (Rsim, Meas or Source) Not available Not available Included Not available
Short circuit to 5 reference points (potential 0 ... 4) directly or via additional hardware (Rsim, Meas or Source) Not available Not available Included Not available

Product Information

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