Protocol conflict Digital Max(Liteon) DVD recorder vs JVC-DV

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ElizabethD
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Protocol conflict Digital Max(Liteon) DVD recorder vs JVC-DV

Post by ElizabethD »

This recorder, model DMD-R0501, conflicts with JVC DVD (s502...I don't recall my number). Both use JVC protocol. Both use device 239. Function codes differ and conflict with one another.
Pretending I know :eek: what I'm talking about here, I see that the signal properties are identical in structure though the timings differ a bit. While this is a temporary situation, I wonder if there's a way to tweak my DVD upgrade in PB making it different from the other machine, so that when I press 3 on the recorder, it won't toggle Power on my DVD for instance. Now, it's already been tweeked a bit by adding repeats. So how much tolerance is there?
Curiously, in the file section a bunch of Liteon DVD and DVR boxes are split about evenly between using JVC protocol for 239 and NEC1 :evil: . I find the whole thing weird, is it? Does that sort of confusion happen often, doesn't 239 belong to JVC and ME and not some other box?
Liz
Tweeking 8910, HTPro/9811, C7-7800, 6131o, 6131n, AtlasOCAP-1056B01, RCA-RCRP05B and enjoying the ride :)
johnsfine
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Post by johnsfine »

Possibly one of the devices can be recofigured to an alternate code set. That would be the best solution, but I don't know where you would find the instructions for how to do that.

Tweaking protocol parameters would take a lot of experimentation and doesn't ultimately have that great a chance for success.

To investigate tweaking the timing, you would do various tweaks by various amounts and see how far you need to go for each device to reach
A) The point where it no longer reliably works
and
B) The point where it reliably doesn't work.

If in any tweak direction, one device reach B before the other reach A then you have the basis for a solution.

The simplesr things to tweak are modulation frequency and overall timing. "Directions" are not just up and down, but whether you change them together or not. For example, some IR receivers would stop working if you just made the frequency 15% higher, but would work again if you both made the frequency 15% higher and made the basic timing (durations) 15% lower. Other IR receivers would have the same cutoff for frequency across their range of valid timing.
The Robman
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Post by The Robman »

Does the conflict also happen when you use the original remotes (ie, does the LiteOn remote interfere with the JVC DVD and vice versa) ?

Have you tried any of the LiteOn upgrades that use the NEC protocol? If so, did they work with the LiteOn, and if so, do they also work (or conflict) with the JVC?
Rob
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Please don't PM me with remote questions, post them in the forums so all the experts can help!
ElizabethD
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Post by ElizabethD »

johnsfine wrote:Possibly one of the devices can be recofigured to an alternate code set
I won't do that, but what does it mean? Change device number in DVD hardware? Just curious.
I will try playing in PB for my dvd upgrade, no harm, and thanks for the hints where to start and for the criteria.
The Robman wrote:Does the conflict also happen when you use the original remotes (ie, does the LiteOn remote interfere with the JVC DVD and vice versa) ?
Absolutely. It all started with LiteOn number 3 shutting off my JVC dvd. So using the Liteon remote I tried a bunch of other buttons, and my DVD reacted, precisely as expected from the hex codes in IR. So I learned some LiteOn signals. Then I dug out some batteries, and using the OEM JVC remote for the dvd (NOT a jp1 upgrade), triggered various activities on that Liteon recorder. Ditto from 8910. That's when I decided to read the existing upgrades here to see if I've gone mad or what, and the rest you know.
The Robman wrote:Have you tried any of the LiteOn upgrades that use the NEC protocol? If so, did they work with the LiteOn, and if so, do they also work (or conflict) with the JVC?
No, I thought about it but ran out of time last night. And I wanted to hear suggestions from here.

I'll report back. While I'm at it, is there anything else that I should look at besides the NEC1 trial?
Liz
Tweeking 8910, HTPro/9811, C7-7800, 6131o, 6131n, AtlasOCAP-1056B01, RCA-RCRP05B and enjoying the ride :)
johnsfine
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Post by johnsfine »

ElizabethD wrote:I won't do that, but what does it mean?
If you knew what it means, and the device has support for it, and you somehow find the device specific instructions, I'm pretty sure you would do that, because it is exactly the right solution to your problem.

Many remote controlled consumer devices are built with support for a second code set. There is some proceedure (not a hardware mod) to tell the device to use the other code set. The professional installers who frequent RemoteCentral often can get the manufacturers to tell them the proceedure and some of those proceedures have been shared there. But the manufacturers tend not to describe it in the online or printed documentation nor to answer that question if asked by ordinary users.

For comparison, one method used by several devices to switch code sets is:

1) Unplug the device (power off is not enough)

2) Wait at least 30 seconds

3) Plug it back in

4) Immediately press and hold the remote power toggle key of a remote already programmed to the second code set.

Devices with complicated menu systems often have a step somewhere in their menu tree that lets you change code sets.

JVC documentation I have lists the device number for VCR's as 67 by default with other choices being 83, 111, and 127. That fits the data I have from RC that JVC VCRs are device number 67 and can be changed if you know how to device 83.

That same JVC document says DVD's are device 111 by default with other choices being 127, 67 and 83. But that of course is wrong, because JVC DVDs are device 239.

But the person who wrote that document was clearly taking input from a document with the numbers in binary. Maybe he just missed the top bit. 111 and 239 differ only in their top bit. So if that's the explanation, the second choice would be device 255 (differs in only the top bit from 127).

All the OBC numbers stay the same when you change the device number. So one path is to take a JP1 upgrade for the JVC DVD and change the device to 255 and see if you can find a way to make the DVD player switch to it.
ElizabethD
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Post by ElizabethD »

The Robman wrote:Have you tried any of the LiteOn upgrades that use the NEC protocol? If so, did they work with the LiteOn, and if so, do they also work (or conflict) with the JVC?
NEC1 has no effect on the DigitalMax nor on my JVC DVD.
And for that group of LiteOn devices which use JVC protocol, there's virtually no difference between Digital Max and LiteOn function codes, 3-5 unique to each, that's it. I posted it under D.
johnsfine wrote:To investigate tweaking the timing...
I haven't done that yet. Currently there's at most 4% difference between the two with about 14% in the lead-out low part.
johnsfine wrote:If you knew what it means, and the device has support for it, and you somehow find the device specific instructions, I'm pretty sure you would do that, because it is exactly the right solution to your problem.
I see now what you're saying :idea: and it makes perfect sense. Thank you very much for digging this out for me.
I found nothing in the user manual in the menus and nothing about code sets on the jvc site.
The only thing I got is the JVC official reset instructions for XV-S502 dvd
www.jvc.com/support/documents/DVD_Procedures.PDF
DVD reset procedure for XVS500-XVS502-XVS600-XVS602
Make sure the reset procedure is performed in interlaced mode i.e. the PROGRESSIVE
indicator must be turned off.
1. Make sure there is no Disc in the tray.
2. Shut off the unit and unplug it from the AC outlet.
3. While pressing both PLAY and STOP buttons on the front panel reconnect the power cord
4. On the front panel “TEST **********" will be displayed
5. Press PAUSE button on the front panel.
6. Wait until green indicator will light up (PROGRESSIVE light--after approx. 10 seconds)on the front panel.
7. Turn the power off and unit is ready to use.
Does the procedure you're suggesting fit in the general logic of how they reset?
Risk of breaking the DVD?
Liz
Tweeking 8910, HTPro/9811, C7-7800, 6131o, 6131n, AtlasOCAP-1056B01, RCA-RCRP05B and enjoying the ride :)
johnsfine
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Post by johnsfine »

Since there is no mention of the remote in that sequence, I don't think there is much hope that the sequence includes a way change code set.

I think it is less than 50% likely that the DVD even has a way to change code set, and even less likely that you have a way to discover it. I was just hoping to be wrong about that estimate and describing the possibility.
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