Getting and Processing Log Data

Every time the Cassie Real-Time Subsystem is run, log data is saved to the local hard drive of the target machine. This log data is overwritten after every run, so in order to get data off of the robot follow the steps on this page before running the Cassie Real-Time Subsystem again.

Creating a Blank SLRT USB

A blank SLRT USB has the Simulink Real-Time kernel, but no application. When booted from the target PC, the kernel will enable the development computer to connect through the Simulink Real-Time Explorer interface.

1. Format a USB drive to make sure there is nothing on the drive already. This is most easily done through the Windows interface
2. Start the Simulink Real-Time Explorer by typing slrtexplr in the Matlab command prompt
3. Set up the CassieV3 target PC as specified in Setting Up Development PC
4. Under Boot Configuration select Removable Disk as the boot mode
5. Click the button to the right of the drop-down menu to create a boot disk, and select the blank USB drive from step 1

Copying Files from Target Computer

1. Follow the procedure in Setting Up Development PC.
2. Boot the target computer from the blank SLRT USB drive created in the previous step
3. Start the Simulink Real-Time Explorer on the development computer
4. Make sure all of the host/target settings are correct and match the settings used to create the blank SLRT USB
5. Click the connect icon in the Targets section of the SLRT Explorer. The red light next to CassieV3 should turn green
6. Double-click on the File System
7. Right-click on the desired files on the target PC and select Copy to Host...
8. Files can be copied to the target by dragging them into the file system window

Occasionally the SLRT Explorer may display an Invalid Port error when the file system is opened. If this happens, the connection can be reset by typing the following into the Matlab command prompt:

    tg = slrt;
    tg.close();

After resetting the connection, repeat steps 5-8 above. If the problem persists, check the target PC settings and reset the target PC.

Copying data from a target with a model running

This process can also be performed on a target PC running any model. Make sure that the robot is not turned off after an experiment, as a reset will overwrite all of the log files. While the electronics are all still running (turn off motor power), connect Cassie to the development computer using an ethernet cable, and follow steps 5-8 above. The only difference is that there should be an application under the Applications section in the SLRT Explorer. Make sure that the application is stopped (press the stop icon) before transferring files.

Processing Log Data

The Cassie Real Time Subsystem produces 4 different log files during operation: message.dat, energy.dat, outputs.dat, and inputs.dat.