I'm interested in a TRC-780 and a MRX-10 for a custom install, but need the ability to use a completely custom two-way protocol with it as it is supposed to integrate with a customer's existing HA system. Is this possible with the MRX-10 and TRC-780 combo?

Some requirements:
1. Customer wants complete two-way capability. This means macros would trigger ascii text for each button press. This ascii text would then be sent over ethernet using a predetermined port. Basically if the ascii text from a button press can show up in a telnet client (e.g. over a tcp socket port), it will work fine.

2. The ability to send status messages over IP from the HA system to the remote's display. This would be for status of what's playing, alarm status following an alarm status change, weather etc...

Thanks in advance!

No. The TRC780 only allows for basic two-way as it is a Zigbee remote. URC calls the TRC1280 remote "Premium Two-Way" as it uses wifi and can send more data to a larger screen. The only two-way data I've seen on a TRC780 is the metadata returned from an ipod docked in the PSX2. I don't know if the SNP1 sends any data back to the TRC780 as I don't have one of those to experiment.

The last time I played with my MRX-10 and TRC780 the ability to write your own two-way drivers was not enabled and you were limited to the drivers that URC had already written.

But the short answer to your question is you can't use a TRC780, you have to step up to the TRC1280 for what you want.

if/when urc enables you to write your own 2 way modules, the TRC780 should be capable of showing 2 way text feedback.  that is how it works with the SNP1 and the PSX2 and DMS amps.

Thanks for the fast response guys!

So if the TRC-780 is zigbee (2.4Ghz), how is the signal range compared to the old CCP remotes such as the MX-900 (418Mhz)? Do most installations require a zigbee repeater/router for a multiroom setup? Typically as frequency increases, range due to obstructions decreases.

I guess the only drawback to the TRC-1280 is that it's not going to have the battery life the TRC-780 has since it uses WIFI? For some reason I can't find the TRC-1280 on Universal's site yet, but the picture here indicates no YBRG buttons?!?:
[Link: cepro.com]

The TRC-780's metadata would work fine for what I need if there were some hack or workaround...

What Duct Tape says is correct. I called URC, what I'm trying to do with the TRC-780 will be possible with an upcoming SDK (according to tech support). URC stated that they do plan to release this, but they did not have an exact date :(