I managed to come up with a solution for my MX-500 and my Samsung. The Samsung has a discrete button for the "TV" spot on the long list of inputs. So my Macro starts by switching to the "TV" tuner and then by choosing TV/Input repeatedly until the correct input is chosen. I have added pauses for this funtion too.

To turn on the TV and choose the cable box the pauses had to be more than 7 seconds long between power and choosing the "TV" tuner location. I had to do multiple pauses with useless commands after each 2.8 to 3.0 second pause as the longest pause allowed with the MX-500 is 3 seconds.

However after some more work reading posts here I realized that what I wanted could be accomplished with the discrete codes mentioned here:

[Link: remotecentral.com]