Use Alexa to Change Cable / STB Channels via Harmony Activity
This is a supplement to my Alexa Harmony Volume Control recipe and uses the same basis to change channels. To make this work, be sure to configure your "Watch TV" activity's devices to be ON while switching activities (do this under Devices -> Change Device Settings -> Power Settings. Mine are set to stay on and only turn off when pressing "Off". Note you also need to have a Harmony Activity created for use as your action. I'll use "ABC" as the reference example: Create a new "Watch TV" activity in Harmony with your desired devices, and save it as "ABC" (or whatever you choose). Then go back to the activity and choose "Customize this Activity" and, under the Activity startup commands, add a step, select your set-top box as the Device (in my case it's a Verizon FIOS), then, under Action, select "Channel Number" and enter the number for your channel, and click "Save". Next up it setting this up in your IFTTT recipe. For the Trigger, specify the words you want to use for the channel, noting that acronyms to should be spaced out, e.g., "ABC" should be input as "a b c", "BBC America" should be "b b c america". For your Action, select the Activity you created, and repeat this recipe for each channel you'd like to use with Alexa.