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TestDrive Power Moding Guide


A TestDrive chassis provides several power output lines called power rails that are used to power TestDrive IO board (internally) as well as external components using the power moding connectors on the back of the TestDrive chassis. Power moding designates the activation of these power rails, which may depend on several system conditions, such as the position of the Key Switch State input and feedback from other external components. This document describes the components of the power moding circuitry as well as the steps required to configure and control power rails.


The following figure provides an internal view of the power moding feature.

At the heart of the power moding circuitry is the Rail Controller that activates the 9 power rails switches according to the input state and the power moding configuration. The battery input passes through a first switch enabling the battery output (BATT). The other 8 power rails switches (ACC, RADIO, CRANK, IGN3, IGN1, IGN0, MP S1, MP S2) are connected to the Battery output. Thus, if the battery output is not activated, all power rails are opened.

The BATT rail is activated using the Battery Control software input (0 or 1) while the 8 other rails are activated using the Key Switch State input (0 - 7). A configuration matrix (Power moding mask) allows defining the rail to be activated for each Key Switch State value.

Additionally to the software inputs, all 9 rails can be configured to depend on hardware input pins labeled Rail Enable pins. These 4 pins act as hardware enable for power rails. This feature can be useful for security reasons or to reproduce real-life power scheme where power shall not be available until another power source is activated. Rail Enable pins are available from the Base Module Elco-56 connector located at the back of the chassis (Slot 1). Rail_Enable inputs can be individually configured to be active low or active high.

Most TestDrive IO boards use power rails as a power source for outputs or as references for input channels. Therefore, not having power moding activated can prevent IO channels from behaving normally.

Of the two power input lines, named BATT and ECU5V, only BATT is involved with the power moding. ECU 5V power input is linked directly to TestDrive IO boards. The GND lines are permanently connected to the main grounding within the TestDrive chassis.

Power Moding Controls

This section provides information on the power moding controls. Refer to the help file of the OpCtrl BaseModule block for more details on each parameter.

Power Moding Battery Control State

This switch powers the battery rail (BATT). When not activated, all 9 power rails are off. When activated, battery and other power rails are activated based on the Key Switch State input and the Rail Enable pins. This switch is accessible from OpCtrl BaseModule Power Moding Battery Control State block input.

Power Moding Key Switch State

This OpCtrl BaseModule Power Moding Key Switch State block input is used to switch power modes. Each power mode defines which of the 8 power rails (BATT excluded) are actives. Up to 8 power modes are supported, values from 0 to 7 are allowed for the Key Switch State input.

The power modes are defined in the Power Moding Mask parameter. See the Example section below for a real-life example with this parameter.

External Rail Enable Inputs

This feature allows configuring hardware to enable pins for selected rails. BaseModule's Rail_Enable digital inputs are used for this purpose. These 4 lines are accessible from the Base Module Elco-56 connector located at the rear of the TestDrive chassis. The inputs are labeled RAIL_EN_INP, RAIL_EN_INP1, RAIL_EN_INP2 and RAIL_EN_INP3.

When a rail is configured to depend on a RAIL_EN_INP pin, it is only activated if the current mode (Power Moding Key Switch State) requires the rail to be active and if the RAIL_EN_INP input is active. It is possible to have more than one hardware enable for a rail. In such case, all RAIL_ENABLE_INP pins must be active for the rail to be active.

It is possible to configure the active polarity (active high or active low) for each RAIL_ENABLE_INP line.

The Rail Enable pins are configured with the following OpCtrl BaseModule parameters. See the Example section below for a real-life example with these parameters.

Rail Enable MasksAllows defining the rails dependency to each RAIL_EN_INP lines.
Enable Active StateAllows setting the active state of each RAIL_EN_INP lines.

Note: For Base Module Boards older than Rev 2.5, there is only one Rail Enable Input whose signal name on the External Elco-56 connector is: RAIL_EN_INP. In this case, the OpCtrl BaseModule block still provides ports and parameters for four enable lines but only those associated with RAIL_EN_INP are actually used.

Usage Example

This section shows the procedure to configure power moding for a typical controller test.


The above figure provides a connection example of a generic controller (ECU). One power supply (bottom left) is connected to Battery (BATT) input section. The ECU receives its power the Battery and IGN0 rail output and provides power to the ECU-5V rail. Additionally, the ECU 5 volts output is connected to the Base Module RAIL_EN_INP enable pin. This will allow preventing some rails to be activated when ECU-5V is not present.


For this example, we assume the following requirements :

Required Power Sequence for the ECU

Step 1Power is applied to ECU Power pin
Step 2ECU generates its SENSOR power (5 volts)
Step 3ECU can now be activated using the IGNITION power pin

Power Modes

Only 2 power modes are required, the OFF mode where all rails are disabled and the RUN mode where IGN0 and MP S2 is activated.

Rail Enable

IGN0 shall only be activated when Sensor Power output (5 volts) is present.

MP S2 shall not depend on Sensor Power.


The following procedure shall allow meeting the above requirements:

  • Open the model in Simulink. The model can be the TestDrive model or any other model using the controller blocks of the OP6000 cards. Basic examples models are provided in RT-LAB folder Examples/IO/Opal-RT/TestDrive.
  • Locate the OpCtrlBaseModule block and open its configuration mask.
  • Set the required power modes in Power Moding Mask.

Table representation:

Key Switch State Power ModesPower Moded Rails 

In the parameter, enter the following matrix:

[0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 1, 0, 1; 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0; 0, 0, 0, 0, 0, 0, 0, 0]

  • Configure IGN0 to be dependent on RAIL_EN_INP in Rail Enable Mask.

Table representation:


In the parameter, enter the following matrix: [0 0 0 0 0 0 1 0 0]

  • Configure RAIL_EN_INP to be Active high in Enable Active State.

Table representation:


In the parameter, enter the following matrix: [1 0 0 0]

  • Close the OpCtrlBaseModule's configuration mask and save the model.
  • Using RT-LAB, compile and run the model
  • Open the user console
  • Set Power Moding Battery Control State input to ON (1). Battery output shall now be activated.
  • Make sure ECU Sensor power (5 volts) is present.
  • Set the Power Moding Key Switch State to RUN mode (1). The IGN0 and MP S2 rail shall now be activated.
  • Set the Power Moding Key Switch State to OFF mode (1). The IGN0 and MP S2 rail shall now be opened.

Rail Enable Tests

  • Disconnect the ECU Sensor output (5 volts) from the RAIL_EN_INP pin of the BaseModule Elco-56 connector.
  • Set the Power Moding Key Switch State to RUN mode (1). The MP S2 rail shall now be activated since it is not dependent on RAIL_EN_INP. The IGN0 rail will remain opened until RAIL_EN_INP is active again.

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