When you press the Watch TV button on your Harmony 300 remote, by default your TV and your cable or satellite box (if you have one) turn on. Pressing the Watch TV button again while you're watching TV will turn those devices off.
If you have a device, such as a cable box or PVR, that you want to leave on all of the time, you can configure your Harmony 300 remote to never turn that device off.
After you have made the changes and updated your remote, when you press the Watch TV button on your Harmony 300 remote, it will power on the TV. You can then control the cable box or PVR by pressing the Cable/Sat button on your Harmony 300.
To change whether a device is left on
1. Go to myharmony.com and log in to your account.
2. From the Home page, click Change or Fix What a Button Does.
3. On the Change or Fix a Button - Device Selection page, select the device you want to make changes to and click OK.
4. On the Change or Fix What a Button Does page, hover the mouse pointer over the Watch TV button on the remote image, and then click Setup.
5. Clear the checkbox for the cable box or PVR.
6. Click OK.
7. Click Sync Remote to update your remote with these settings.