Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » DTS + CP45 strange problem with format switching

   
Author Topic: DTS + CP45 strange problem with format switching
Luciano Brigite
Master Film Handler

Posts: 277
From: Sao Paulo, SP, Brazil
Registered: Jan 2002


 - posted 12-01-2009 04:33 PM      Profile for Luciano Brigite   Email Luciano Brigite   Send New Private Message       Edit/Delete Post 
Hello ..

This is somehting new to me and started out of nowhere with a CP45 and a DTS6D.
The CP45 started to switch to NS2/digital input during the shows, this input is used to feed signals from the DTS6D but the strange thing is that the DTS unit isn't being used and is switched off ( thye film being presented at the time doesn't have DTS)wit show stopped ( interval) the NS2 led is blinking randomly, sometimes going fully on for a second or two then off again. Removing the automation/control cable linking the DTS to the CP puts an end to this random switching.
Question is.. what can be causing this problem? can it be a sign of an upcoming problem with the CP's logic control?
Again, the DTS unit is turned off, but if it's format control cable is left connected to the CP,the CP NS2 format led starts blinking and if left as is, it ends switching to that format at random. I'm lost on this because I never seen something like this..

Thanks!

 |  IP: Logged

John Hawkinson
Film God

Posts: 2273
From: Cambridge, MA, USA
Registered: Feb 2002


 - posted 12-01-2009 05:13 PM      Profile for John Hawkinson   Email John Hawkinson   Send New Private Message       Edit/Delete Post 
Well, bad cable, bad CP45, or bad DTS6D. Does it change if you:
  • Unplug the cable at the CP45 end versus the 6D end
  • Wiggle the cable
  • Swap the cable
Never heard of this... Maybe bad grounding?
--jhawk

 |  IP: Logged

Demetris Thoupis
Phenomenal Film Handler

Posts: 1240
From: Aradippou, Larnaca, Cyprus
Registered: Apr 2001


 - posted 12-01-2009 05:40 PM      Profile for Demetris Thoupis   Email Demetris Thoupis   Send New Private Message       Edit/Delete Post 
5V are being send from the CP to the DTS to power up the internal switching relays for format change. It seems that when you have the DTS unit off, the formal relay for DTS pulse has remained latched and thus fooling the processor that DTS is actually active. When you power off the DTS unit make sure the discs are in stop mode and not in playback. Try switching the DTS unit on and have it on to check if the problem still is there even though you are not playing a DTS equiped feature. Try then switching it off and see if the problem occurs. If it does then it probably is the DTS6D unit. In any case in Europe there is a trade in promo for a 6D to exchange with an XD20 unit so perhaps its time to upgrade. Have in mind that the 6D is not currently supported as it outlived long enough its life span. Hope the above helps to narrow your problem down.
Demetris

 |  IP: Logged

Luciano Brigite
Master Film Handler

Posts: 277
From: Sao Paulo, SP, Brazil
Registered: Jan 2002


 - posted 12-01-2009 06:27 PM      Profile for Luciano Brigite   Email Luciano Brigite   Send New Private Message       Edit/Delete Post 
Hello,

With the format control cable disconnected from the CP, it works ok, no led blinking and no random format change. re-connecting the format cable to the CP it starts instantly to do the problem mentioned. For now it's running with the control cable disconnected and the DTS unit wasn't being used at the time this problem started.
Switching on the DTS won't change the situation. removing the power cord from it also won't change anything. it only stops when the control cable is disconnected.

 |  IP: Logged

Demetris Thoupis
Phenomenal Film Handler

Posts: 1240
From: Aradippou, Larnaca, Cyprus
Registered: Apr 2001


 - posted 12-02-2009 12:27 AM      Profile for Demetris Thoupis   Email Demetris Thoupis   Send New Private Message       Edit/Delete Post 
The relay inside the DTS must be latched. Check from the Processor end of the cable to see if Pin 25 and 13 or 25 and 10 are shorted together. If they are disconnect the cable from the DTS end and check again. If they are not when you disconnect from the DTS end the problem definately is a latched relay inside the DTS. Relays have the tendency when getting hot to stick together to the Normally Open connection.
Demetris

 |  IP: Logged

Pete Naples
Phenomenal Film Handler

Posts: 1565
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 12-02-2009 02:30 AM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
The CP45 is a bit strange, well different to it's predecessors, in terms or automation switching and status ID lines.

Try sticking a wee signal diode in the NS2 and GND lines (observing polarity obviously). This should block the voltage coming from the CP.

I had a similar situation connecting a DMA8+ to a CP45, now the DA20 book desrcibes using some sort of automation interface card from Dolby which is not and never has been available in the UK. So I wired pin to pin and the damned thing sat there flip-flopping between NS1 and NS2. A couple of small signal diodes, I don't recall exactly what offhand, probably the same 1N4148 diodes used in Cat243/443 C55/65 logic cards, as I usually tend to have a pile of those in the car someplace.

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.