Simulating devices

Run an application on real EtherCAT devices, on simulated ones, or on a mix of both, and link each drive for all three.

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An application can run on real EtherCAT devices, on simulated ones, or on a mix. You choose with the system mode in config.json and the Simulation switch of each domain.

Simulation
no hardware needed

"Mode": "Simulation"

Every device is simulated, whatever its domain’s switch says.

Production
the real machine

"Mode": "Production"

Every domain with Simulation off runs on the real bus.

Mixed
some real, some simulated

"Mode": "Production"

Domains with Simulation on are simulated; the others run on the real bus.

How a simulated device is linked

Every drive entry can carry two links. The production link connects it to the application and is always there. The simulation link connects the same entry to the simulator and only counts while the device is simulated. The data still passes through the device’s entries, so the rest of the application cannot tell a simulated drive from a real one.

This map shows one axis of the standard robot configuration. Paths starting with …/ are under root/AxesControl/actuatorControlLoops/actuatorControlLoopNN/, where NN is the axis number; the other paths start with root/. Array parameters such as DriveLogic/driveOpMode and Simulator/targetPosition take the channel of the axis: 0 for the first axis, 1 for the second, and so on.

Production link always connected Drive entry Simulation link only when simulated rxPDO: to the drive DriveLogic/driveControlWord 6040:00Controlword handled by the simulated drive DriveLogic/driveOpMode 6060:00Modes of operation handled by the simulated drive …/motorPositionTarget 607A:00Target position Simulator/targetPosition …/motorVelocityTarget 60FF:00Target velocity Simulator/targetVelocity …/motorTorqueTarget 6071:00Target torque Simulator/targetTorque …/motorTorqueOffsetTarget 60B2:00Torque offset Simulator/targetTorqueOffsetavailable, not linked by default txPDO: from the drive DriveLogic/driveStatusWord 6041:00Statusword handled by the simulated drive …/motorPositionActual 6064:00Position actual value Simulator/positionValue …/motorVelocityActual 606C:00Velocity actual value Simulator/velocityValue …/motorTorqueActual 6077:00Torque actual value Simulator/torqueValue …/sensorTorqueActual vendor-specificTorque sensor Production link: always connected Simulation link: only when the device is simulated

The control word, mode and status word have no simulation link. A simulated axis gets a simulated drive in the drive logic instead, through the device’s Link Simulation described in the Simulation tab.

Set up each mode

Start with Simulation to build the application without hardware, then Production for the real machine. Mixed combines the two, so it assumes you know both.


Run without hardware

  1. In config.json, set the system mode:

    "Mode": "Simulation"

    Every domain is now simulated. The domain’s Simulation switch in the Domain Configuration Panel makes no difference in this mode.

  2. In the link files, the groups with "SystemMode": "Simulation" or "All" apply. Use a Simulation group to override what has no hardware behind it, for example a physical emergency stop.

  3. Give each drive a Link Simulation: open the device’s Settings tab and link it to root/DriveLogic/driveSimulation, with the channel of the axis. This tells the drive logic to simulate the drive.

    ECAT tool, Settings tab of device Axis1: Link Simulation linked to root/DriveLogic/driveSimulation on channel 0

  4. Add the simulation links to the drive entries, as on the right of the link map: the targets go to root/Simulator/targetPosition, targetVelocity and targetTorque, and the actual values come from positionValue, velocityValue and torqueValue. Use the channel of the axis.

    Open the link’s properties with and switch Simulation on. The turns blue: the link only applies while the device is simulated.

    ECAT tool, entry 607A:00 Target position with two links: the production link to motorPositionTarget and the simulation link to root/Simulator/targetPosition on channel 0

Deploy the configuration and start the application: it runs on the simulator.


Run on the real machine

  1. In config.json, set the system mode:

    "Mode": "Production"

  2. In the link files, the groups with "SystemMode": "Production" or "All" apply.

  3. In the Domain Configuration Panel, switch Simulation off for every domain.

    ECAT tool, Domain settings for domain Robot with the Simulation switch off

  4. Link every drive entry to the application, as on the left of the link map. Use the axis number in actuatorControlLoopNN and the channel of the axis for array parameters.

    ECAT tool, entry 607A:00 Target position with its production link to root/AxesControl/actuatorControlLoops/actuatorControlLoop01/motorPositionTarget highlighted, and its simulation link below

    The torque sensor has a manufacturer-specific index. Look it up in your drive’s ESI file.

Simulation links can stay in place: in production mode they are ignored unless the device’s domain is simulated.

Deploy the configuration and start the application: it runs on the real drives.

Older version: Robot App v1 production mode.


Simulate some devices on the real machine

  1. In config.json, set the system mode to production:

    "Mode": "Production"

  2. In the Domain Configuration Panel, put the devices you want to simulate in their own domain and switch its Simulation on. Keep the real devices in a domain with Simulation off.

    ECAT tool with two domains: Robot with Axis1 on the real bus, and Robot Simulation in simulation mode with Axis2 to Axis6

  3. Set up the simulated domain’s devices as in the Simulation tab, steps 3 and 4, and the real domain’s devices as in the Production tab, step 4.

Because every entry can carry both links, one configuration covers all three modes. To move a device between real and simulated, move it to the other domain.