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Configuring BBH SCU with AKD2G SRA parameters

This article shows how to make a simple safety application with KAS and SafePLC2. The Functional Safety parameters for AKD2G SMMs can be configured through either AKD2G WorkBench or through the BBH SafePLC2. Both methods are described here.



  • PxMM 
  • AKD2G Single / Dual Axis - FS2 / FS3 models
    • Wiring: Digital Outputs SOUT1-4 connected to Digital Inputs SIN1-4
  • BBH SafePLC2 SCU-1-EC


  • KAS IDE and Runtime  V3.05.8430 (production release) or newer
  • BBH SafePLC2  V1.7.1.8126 or later
  • AKD2G Safety certified Firmware
  • SMM Firmware version  V0.71
  • SCU-1-EC firmware version 0.62 or later

Ethercat Network Connection

  • Master: PxMM
  • Slaves: AKD2G and BBH Safety Controller 


AKD2G Dual Axis Drive with SRA Parameters Configured in Workbench

This is a very simple application just to demonstrate the steps involved in making the KAS and SafePLC2 application work together.

  1. Open a new template project in KAS (Any template project should be OK)
  2. Set the IP Address of the controller and connect to the controller
  3. Scan EtherCAT network.
    • The controller should have discovered AKD2G and the SCU-1-EC
  4. Modify the AKD2G safety modules.
    1. Delete the default AKD2G SRA Parameters Modules Module_1 and Module_2.
    2. Add 'SRA Parameters Configured via Workbench' modules to AKD2G. Right-click on the AKD2G node and press Add Module in the context menu.
    3. Select the "Axis 1, SRA Parameters Configured Via Workbench" module in the EtherCAT Module Selector windowimage
    4. Add module "Axis 2, SRA Parameters Configured Via Workbench" for the 2nd Axisimage
  5. Map the PLCOpen axis to the drives in the EtherCAT view.
  6. Now add a SafePLC2 project to the KAS application.
    1. Right-click at the controller Node
    2. Select the “Add SafePLC2 Project” menu option
    3. SafePLC2 node will be added to  the project explorer as shown below.
  7. Double click on the SafePLC2 node to launch the BBH SafePLC2 Application.
    1. In the following pop up click "Yes" to launch Safe PLC2.
    2. The SafePLC2 flash screen will launch and SafePLC2 will be starting.
    3. On launch the SafePLC2 will display the following information pop up message. Click OK.
  8. SafePLC2 will automatically add the safety devices in the KAS IDE project explorer to the SafePLC2 application.
    • The Safe ID and the EtherCAT address for the devices are automatically populated.
  9. Make the required application changes.
    • In this example, we set Logic1 to enable the STO for Axis 1 and Axis 2.
  10. Via the tool bar: Save, Compile and Send the configuration to the SCU-1-EC.
    1. Click on the Device Interface to connect to the SCU-1-EC.
    2. Click 'Connect' button to connect to the SCU-1-EC. First you may need to click on the "Connection Settings" button to select the proper port on the PC.
    3. Click the "Send Configuration" button to send the compiled Configuration to the SCU-1-EC.
    4. After successfully sending the configuration to the SCU-1-EC, the SCU-1-EC 7 segment display will show "8" indicating the SCU-1-EC is in the "Run Intern" state.
    5. Now return to the KAS IDE
  11. In the KAS IDE, click on the ‘Compile’ toolbar button to compile the KAS Application.  Click “Yes” to import changes from the SafePLC2 project when prompted.
    • This will automatically create in the project the PDO connections required for the FSoE communication channel .
  12. Click on the Download button to download the KAS Application
  13. Click "Run" to run the application.
  14. When the EtherCAT Network reaches the OP mode, the FSoE communication will be activated and the SCU-1-EC will transition to "Run" state and the 7 segment display will show "4". The PxMM will show a "o."
  15. AKD2G workbench Status window (click on button in the Worbench bottomtray)will show the AKD2G Safety Status as below.

AKD2G Dual Axis Drive with SRA Parameters Configured in the  SafePLC2


  • Any previous Safety Configuration in the AKD2G should be invalidated and the SMM (safety motion module) must be expecting the configuration from the Safety Master SCU-1-EC.
  • Please verify the Safety Parameters Viewer in Workbench and ensure the System State is  "3-Configuration required". See below.

The steps to configure the SRA parameters in the SafePLC2 are the same as SRA Parameters configured in Workbench except for the following.

  1. Skip step 4. By default, KAS configures the AKD2G modules that expect the parameters configured through the Safety master. So there is no need to modify the AKD2G Modules.
  2. Configure all the Safety Parameters in the SafePLC2 for each AKD2G module in Step 9 along with the application steps.
  3. In the KAS IDE add a  "FSoEParamsInit" function block. This function block initiates the SRA Parameter transfer from the SCU-1-EC to AKD2G. It must be executed after the EtherCAT network is up and operational (OP mode).
    • Refer to the attached KAS application "AKD2G_FS2_SRA_Parameters.kas" program 'TransferFSoEConfigurationFromSCU'
      The code waits for the Motion Engine to start and then initiates the SRA parameter transfer to the AKD2G.

Known Issues

  • AKD2G FS3 drives SRA Parameters through the BBH SafePLC2 needs the following workaround.
    • The parameter on the object 0x3151:1 (If you have a 2 Axis, then  3251:1 for second axis) should be changed to 360 instead of the default value 3600/- This is a mismatch between AKD2G SMM and the ESI file default value.
  • When negative numbers are used for signed Parameters in SafePLC2, the limits are not working correctly. BBH is currently looking into this.