Using the Philips LCD TV original remote to have my MX-700 "learn" all the ir codes, an odd thing happened. Every code was learned "GOOD", but only works for the first push of the button. Any subsequent pushes of the same button sends the code (the ir receiver lights up), but nothing happens. If I push a different button, then push the original button again, it works (but only for one push). I can't scroll through the tv inputs or the preset audio and video settings, etc.

The MX-700 operates the other components perfectly (two satellite receiver code sets imported from a different MX-700 device file). I also downloaded the codes to another MX-700, and the same "single push only" button problems ocurred.

Any suggestions?

Something like this?

[Link: remotecentral.com]

Your TV uses the Philips RC5 protocol and tracks the toggle (parity) bit. The MX-700 cannot (currently) learn these alternating codes but can deal with them if the device is in the HTM code database.

Not sure whether or not it will work if you import these codes from a CCF file.

Greg

So what you're saying is that "learning" the Philips codes can cause this "one-push only" button problem, but using internal database or ccf files might work?

I'll give it a try.

I don't know what "tracking the toggle bit" means. I really would like to understand why a single button push works fine, but the same button pushed again (1 second or 1 minute later) doesn't do a thing.

I'll try to explain this better and hope it makes sense.

The format of Philips' IR protocol is different from most others in that they tack on an extra bit at the end of each key and toggle that bit after each keypress. So, if you press the "3" key repeatedly, the Philips remote sends out "3"0, "3"1, "3"0, "3"1, "3"0...

The MX-700 is only capable of learning "3"0. Pressing "3" repeatedly sends out "3"0, "3"0, "3"0, "3"0...

The Philips TV is faithful to the RC5 protocol; once it receives a "3"0, it will not accept the "3" key again until it sees a "3"1 or some other key. This is what I mean by tracking the toggle bit. The sequence "3"0, "4"0, "3"0 also works fine.

Some manufacturers that use the Philips RC5 protocol in their devices ignore the toggle bit because they know that most universal remotes on the market cannot learn the alternating bits. These systems will happily accept "3"0, "3"0, "3"0... (or "3"1, "3"1, "3"1, "3"1... if that's the code your remote learned) Some devices give you the option to ignore the toggle bit.

Note that this is a non-issue for most other IR protocols because they don't use toggling bits and will send out the exact same sequence when you press a key multiple times.

Bottom line: Because the MX-700 cannot learn the RC5 codes properly, HTM tries to add these codes to their database so that we don't have to learn them. I don't think that mere mortals have the tools to do this on their own.

People in this forum have asked HTM to incorporate two-phase learning into MX-700 firmware so that the remote can recognize and learn the alternating bits in protocols such as RC5. We still have not seen an answer from HTM and suspect that this may be beyond the remote's hardware capabilities.

Please let us know if you are able to use a CCF file to get these codes into the MX-700.

Thanks...

Greg

Is this why my Philips LC6231 projector will only respond to my MX-700 every now and then! I have learned these codes several time and they work then the ontother day nothing?. HTM has no files for Philips projectors. :(

Greg- Thanks for the explanation. Are you a school teacher? I totally understand the problem now (you're good). When I have some time I'll try every Philips ir code set I can find, but I'm not getting my hopes up.

Just out of curiosity, cna the Philips Pronto line of remotes handle (learn) this type of ir code, being from the same manufacturer and all?

Just out of curiosity, can the Philips Pronto line of remotes handle (learn) this type of ir code, being from the same manufacturer and all?

The Pronto remote should recognize RC5 codes as such. It has protocols designed specifically for handling RC5/RC6/RCMM (but does not do other types of toggle bit codes).

A while back I had an issue with the MX-500 and my Philips TV. While the Philips TV would still respond to repeated presses of learned RC5 codes, it required a lenghty delay (1 second) between each press. What codes were included in the MX-500's database, however, properly generated toggle bits. The problem was, about a third of the functions were missing, and the rest were all scattered around in useless places (and incorrect places where I had to overwrite them).

When I upgraded my config to the MX-700, I was able to map out every function in the database that worked, no matter where it was located, and then dragged them to more logical positions. The rest were learned, but fortunantly all important functions were covered by the database.

Without anything usable in the database, I can see that you have a real issue there. Perhaps URC would consider upgrading the code database for your device.

Daniel, is there an email address and person's name at URC to which I could send such a request? I would think with this toggle bit issue, an expansion of the Philips database codes would make a lot of sense for URC.

URC knows about the toggle bit problem on the MX series excluding the MX-3000.

Try contacting Mike Gifford at [email protected] or call (800)-901-0800.

While you have their attention, you may also want to ask them if they have any plans to address this learning limitation and if they plan to release a utility that will provide do-it-yourselfers a means of creating the device files on their own either from CCF files or by inputting hex codes.

Good luck!

Greg