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projector switches inputs all by itself?
gregr
Posts: 54
I am baffled by an install we finished last spring where all 3 Sanyo projectors will mysteriously and randomly switch from computer1 (on HD15) to computer2 (on DVI). The only signal to the machines is RGBHV to computer1. As far as I can tell, this model (PLC-XT16) does not have any auto-source switching capability.
The projectors are all controlled via RS-232 on an NI-3000 with an MVP-8400. The only command strings to the projectors are for power, and queries for lamp hours every minute, and queries for status and temp. every 10 sec. Command strings for input switching never appears in the code.
As per the manufacturers advice, we have blocked the IR sensors front and back to rule out stray IR.
What a weird symptom-started occurring 6 months after install was finished and is totally random-sometimes one machine will switch 5-6 times/hr, and the next hour never does it once. Disconnecting machines from RS-232 control has produced no clear-cut results.
Has anyone ever dealt with anything like this?
Thanks
The projectors are all controlled via RS-232 on an NI-3000 with an MVP-8400. The only command strings to the projectors are for power, and queries for lamp hours every minute, and queries for status and temp. every 10 sec. Command strings for input switching never appears in the code.
As per the manufacturers advice, we have blocked the IR sensors front and back to rule out stray IR.
What a weird symptom-started occurring 6 months after install was finished and is totally random-sometimes one machine will switch 5-6 times/hr, and the next hour never does it once. Disconnecting machines from RS-232 control has produced no clear-cut results.
Has anyone ever dealt with anything like this?
Thanks
0
Comments
I haven't had issues with projectors, but some IT equipment had strange things happening along those lines. The power grounds to the equipment we from different panels, and it was enough difference and noisy lines to cause an issue. Might see if you have a difference in Potencial across the units or noisy power... good luck. These can be hard to find....ROO
It has always driven me crazy that in the pursuit of making devices idiot-proof by putting all this automatic crap in, they break all the tweaks and adjustments the experts have already applied - when they even allow for any expert involvement at all. I've even seen monitors (Princeton Graphics and Loewe come to mind) that will actually shut off if they don't detect a signal, so if your PC input changes resolution, the dang thing turns off. It wreaks proper hell with an installer who has a bad RGB connection, trying to troubleshoot when the stupid thing keeps shutting down on him. It's one of the most brain-dead conventions I've seen in the industry.
I should have said that there is an FSR/Folsom OMNI 2000 dual-scaler switcher in the system so the output to the projectors always (barring a defect) has sync. This should be sufficient to keep the projectors locked onto that input. In addition, I have disconnected the sync lines manually to determine if I could intentionally cause the symptom to occur. Of course, the display blanks, but never switches inputs when I do this. Also, you would think that if the signal is somehow at fault, whenever one projector would glitch, the other two would also, since they are all fed by the same RGBHV distribution amp.
Not exactly like this, but I've had a projector that wouldn't power off when told to, and required as many as 30 or 40 repeats of the command before it would power off. As a workaround, I put in code to poll for power status once a second and re-send the 'off' command if the power wasn't what it should be. You could do something similar for input selection. This wouldn't prevent it from randomly changing inputs, but at least it would go right back to where it's supposed to be.
I haven't dealt with the PLC-XT16, but I've had very good results with the PLC-XT11 and PLC-XT51. IMHO they have a nice, easy straightforward API. Not like, say, doing lamp hours on an NEC.
Anyway, hope this helps.
chill, this is what I am basically doing as a band-aid until I figure out the real problem. Just sending a command to go to input 1 every 10 seconds.
The PLC-XT11 is basically the same as the the 16.
are the NEC's really hard to deal with? I have been considering them for our default projector, but I don't need difficult command protocol.
gregr,
Funny you should ask... I just finished a NetLinx module the other day for an NEC NP2000. The protocol doc is available at the NEC website - sorry, I don't have the exact URL.
I would say this is one of the more programmer-hostile protocols I've encountered lately. Let me count (some of) the ways: 1) all hex, so errors are not obvious; 2) needs checksums; 3) same header in the response means different things depending on what you sent; 4) no fixed command delimiter; 5) commands and responses are variable lengths; 6) lamp hours and some other things come back with the bytes in the opposite order than what we're accustomed to, i.e. the low-order byte comes in first; 7) command and response strings contain a code for the model family, which complicates making a module portable for different models. None of this is insurmountable, but they make it more difficult (and time-consuming, and error-prone) than it needs to be.
For easy control, I really like the Sanyos these days. Christies are good too, since they sell OEM Sanyos as their boardroom-class product line. Mitsubishis seem to be nice and quiet, and they have a simple protocol, but the protocol doc is full of errors and omissions.
As for status polling, I routinely do that anyway, because I like my feedback to be real: if my touchpanel's ON button lights up, it's because the projector actually claims to be on, not just because someone pushed the button.
Hope this helps...
Hi all.
I was wondering if anyone has tried the lastest Duet modules for many of the NEC displays? It is my understanding that much effort has gone into making them easy to use and robust.
Any feedback would be appreciated.
yes, I have tried unplugging two of them and leaving the third connected-then none of them acted up!
Problem is so intermittent it is hard to make any sort of determination.
Thanks for the info re the NEC's.
I'll also second Dave's idea regarding video signal. If you've got a change in signal timing, or a weak signal getting to the PJ, it could be causing it to drop out and switch to a higher-priority input. I would double check cabling, and scaler or other switchers that are installed prior to the projector. Make sure no one has changed any settings and that no changes are happening during use via the AMX. You can also consider manually setting the video input parameters instead of leaving it on 'auto'. I would also try pulling one cable out like the H, or V and see if that will trigger it to change inputs. If it does, there's an indication that you may have issues with signal.
Lastly, make sure your RS-232 cable is not a full pinned cable. Make sure you're using only the pins you need. There have been other threads on this matter, here's one of mine: LINK.
Hope you find the problem quickly.
--John
We have the NPxxxx VPs operating just fine like this. Lamp hours, source feedback, the works! No checksums to perform either!
i know this isn't the Sanyo, but i just had a similar problem with an NEC LCD monitor with a built-in Digital TV tuner.
using IR codes, all we want to do is turn the thing on. Ideally, it should always remain on Component input (trying to change inputs over IR can only be done via a cursor controlled menu). this works, for a while.
by about the fifth time the monitor gets turned on, it will fall back to the built-in Digital TV tuner. this is regularly repeated. all TV station programming has been removed, so nothing appears but white noise.
there is no loss of component signal, a Denon amp provides the switching and is on well before the display is on.
i know it doesn't quite fit the bill for your problem, but it would seem there is some suspect firmware programming out there (shock - horror
at this stage, i've told the customer i can do nothing about it. i mean, i could try to control the menu input selection, but that would take about 3-5 seconds every time an input is choosen and may still be unreliable.
note: this LCD display doesn't have a serial port, so IR is the only option.
in short, some products are just too much of a problem to try to automate, particularly if someoneelse sold them the product.
guess it's not a lot of help, but it's just to let you know you aren't the only one having such a problem
Well, I think the book can be closed on this one. We installed Surge-X flat-paks and UPS's at each projector. No issues since.
Just goes to show that there is more to AC power than is often appreciated.
Thanks for all your responses.