My Movies does support serial control for powering on and loading a given changer slot. The screenshots below are from the Collection Management application for My Movies 4.04 (Build 4) and pretty much speak for themselves. Couldn't be easier to setup and use. Also, I've remained on My Movies 4, because with My Movies 5 you are no longer able to export your local database (profile data and cover images), then importing it to their mobile app. And the big one, the synchronization model is mandatory and on steroids with My Movies 5 and blows. I have no interest in the Collection Management application being tied at the hip with their online servers, but I digress.

Tools->Disc Changers:


Tools->Disc Changers->Configure Disc Changers:




Title->General Profile Data->Discs->Assign Discs:


The one issue I have with the changer support is that when selecting a disc from My Movies for WMC7 (either directly or by way of the mobile app) and choosing "Play" the changer plugin will send the command to power on the changer, then request and wait for confirmation from the changer that it's powered on before sending the command to play the disc.

Unfortunately what can happen is that if My Movies doesn't get an answer back from the changer that it's powered on after a certain period of time an error message will be displayed and the sending of the command to play the disc is aborted. And here's the thing, to date I have yet to see My Movies not power on the given changer. Sometimes it just takes longer for the changer to power on and I assume then be able to receive and answer back that it's powered on per the command being sent to play the disc. My Movies will also from time to time state it can't open the com port. Happens rarely for me, but happens nonetheless. That error will happen the moment you attempt to play a disc and requires a restart of the HTPC in most cases.

Be that as it may, the main benefit of My Movies for me is the ability to browse my Blu-ray collection using My Movies for WMC7. Being able to initiate playback of a given disc within the interface is just the icing on the cake. That being said, even if I do use My Movies for WMC7 to initiate playback of a disc, I'm still then changing to the particular changer activity with my Pronto. As such, I'll pre-select the changer slot anyway with my Pronto prior to going to the changer activity. (See my prior post.) Makes no sense not to. If My Movies ends up failing to play the disc I've already got the changer slot pre-selected once getting to the changer activity and can just send the command myself with a press and hold of the "Ok" hard button. In fact, even if I don't need to I'll send the command anyway that way the value is stored in my Pronto as I'm tracking the last disc played for each of my changers now.