Combo Units

Joe

Here's something a bit interesting that I ran into last week. It involves DVD/VCR combo units. Our corporate customers love these, but from a programming standpoint, they can complicate things slightly if treated as 2 separate units. This particular unit has the Composite Video Out for the VCR, and the DVD can use Composite, S-Video, or Component output. The audio is combined on L-R RCA jacks. We ran the VCR to Input 11 on the matrix switcher, Composite Video (which was converted to S-Video) and Audio. We then ran the S-Video to Input 12 on the matrix switcher, video only.
Now here's where things got tricky. When selecting VCR on the left screen, I pulsed the combo unit with the VCR command, switched video to left screen and audio to main output. When selecting the DVD to the left screen, all is the same except that the audio from input 11 needs to be routed to the main outputs. Not a problem. But when the VCR is selected on the left screen and then DVD is selected on the right screen, the DVD will appear on both screens! After searching the code for a while, we figured out that once the unit gets the DVD command pulsed to it, it will send the DVD signal out ALL 3 video outputs, since the S-Video and Component are optional video outs for those units that will accept these signals. The unit does not have fully dedicated outputs for each 'half' of the unit, just 'supplemental' video outputs.
Just an interesting observation...

[Deleted User]

I've also seen this scenario on several combo units. Customers typically don't understand the need for separate units (they may believe that two units take up more space or that you are just trying to charge them more). But if you want separate outputs, you will need separate devices.

Thomas Hayes

Hi Joe
I ran into the same issuse earlier this summer. My boss decided we MUST go with a combo unit to save space. He then added a crosspoint switcher and a TP with a video window that he wanted to use to preview the DVD/VHS while watching the other. Guess what, it didn't work. I personally do not like the combo units because they have a tendency to be a lot of BS to program and track which side is active. I know of a few companies and programmers that refuse to use them.

DHawthorne

Combo units are a compromise technology, and most clients purchasing control systems aren't going to be happy with a compromise. That's how I broach the subject when it comes up, then try to expalin what they are giving up for the saved space. Most agree that they don't want to go that route, and the ones that don't have at least been warned.

When I have programmed them, I've been lucky enough to at least find discreets for the mode the units I've used, but I find that manually inserting a disc or tape will override them, in which case I tell the customer they need to switch sources on their remote if they switch media.

bbriles

My main problem with combo units is the fact that I have yet to find one that has discrete power functions for the IR. Has anyone found a unit that does?

alexanbo

I've used the JVC HR-XVC27U and it seems to work with the discrete power codes for JVC VCR's. You do have to send the VCR select command first if the unit is in DVD mode to have it respond to the command.

For example if the unit is in DVD mode and turned off, you have to send a VCR mode command to the unit then the power on command to the unit to get it to turn on.

The one thing I dislike about the unit though is that if there's a DVD in it and you turn the unit on, it will turn on and then automatically switch to the dvd input. That means in order to turn on the unit and ensure that the unit goes to VCR/Cable TV mode you have to wait until the unit starts up and the unit has possibly automatically switched before sending out the VCR mode command.