Business Phone Systems

Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Nov 2018
Posts: 3
Bigmacx Offline OP
Member
OP Offline
Member
Joined: Nov 2018
Posts: 3
Our school has a Dukane MCS350 mounted on the wall. The computer portion has apparently failed and I'm wondering how hard it would be to connect a Raspberry PI to the analog portion and just output sound that way. I'm good with the PI interfacing and programming but need to know more about the 2-wire card in there.

[Linked Image from i.imgur.com]

I think we can just disconnect everything but the PS, Amp, 2-wire card, and speakers, then use the PI as the controller and sound input. The 2-wire card doesn't really seem that complicated with only a couple of connectors. Does anyone know where I can get more board-level diagram of at least the pinout descriptions for these connectors? It seems the dense 40pin'ish connectors select which speaker to output to and then a master audio input is fed into the board. I don't have manuals

Way I figure, it wouldn't be too hard to make the PI control the 2-Wire board if I knew more about those connectors. Any direct help would be great or even a push in the right direction would be appreciated. We're trying to use the existing premise wiring and such without buying a new system.

Atcom VoIP Demo
VoIP Demo
Joined: Jan 2010
Posts: 189
Member
Offline
Member
Joined: Jan 2010
Posts: 189
The speakers are all on a common bus when in the "off" position. The program relay keeps the amp disconnected from the speaker circuits when idle. You could bypass the program relay on each card and feed the 25V audio in that way. You won't be able to dial individual rooms or recoeve calls but you'd at least have audio out to each circuit.

To get individual rooms is way more complicated and require interfacing with the big ribbon cable on the front of the card. 4 of the pins are for board selector, the others are for circuit selector. But that's about the extent of my knowledge on it.

Are you trying to complete replace the MCS digital card with the Pi, that it to say, handle all of the system functions, the classroom callins, run the bell schedules with zones, master clock, get the ACCs working again etc..., or are you just trying to get audio to come out of it on an all call basis??

We have parts for this system that we could get to you to save you the trouble of reinventing the wheel. Click on the logo in my signature for more info.

Good luck!

Joined: Nov 2018
Posts: 3
Bigmacx Offline OP
Member
OP Offline
Member
Joined: Nov 2018
Posts: 3
Highest priority is to get the bell schedule working, so that just needs an ability to send out sounds. Secondary is for overhead announcement from a person at a single physical location, but that's easy once #1 is working. Frankly, this system was only ever used for those 2 functions and from what we've been quoted by the vendor, replacements for these card is prohibitively expensive. I don't even know which one is bad. There are ones for sale on eBay depending on what's needed. We're not ready to spend a lot and there's a crossover pricepoint of fixing this vs waiting to buy a drop-in current model that keeps the speakers/wires.

We do have the PI's and misc digital type resources on hand here to make small kinds of interfaces. I bet the circuit selector for individual rooms is just some TTL encoding on those 40pins. 16 channels would need either 16 discrete input selectors or some form of 4-bit binary. Since in the original design I believe multiple speakers could be activated, I bet the 40pin has 16 discrete lines somewhere with one tied to each of the 16 channels. The board seems easy enough to trace to the buffering IC's and reverse engineer the encoding just from that. Thought maybe someone here had a technical drawing or diagram of this card that might be helpful

Joined: Nov 2018
Posts: 3
Bigmacx Offline OP
Member
OP Offline
Member
Joined: Nov 2018
Posts: 3
Will someone tell me what these switches do? I there a table of options you could post? I don't have any documentation with our system. Thanks

[Linked Image from i.imgur.com]

Joined: Dec 2007
Posts: 6,750
Likes: 10
Retired Admin
*****
Offline
Retired Admin
*****
Joined: Dec 2007
Posts: 6,750
Likes: 10
Tim10 will have your answer.

I will send him a PM for you.


Dean
Photographs:
https://www.instagram.com/deanwilsoncanby/
https://fstoppers.com/profile/deanwilsoncanby
https://www.facebook.com/Dean-Wilson-Photography-112841337020414

Please don't confuse your "Internet Search" with my licenses, certifications and over 30 years experience.

"Thank you for calling Technical Support. If you feel you have reached this number in error, please hang up and press redial."
Joined: Jan 2010
Posts: 189
Member
Offline
Member
Joined: Jan 2010
Posts: 189
ACC switch = binary representation to the system of how many ACC consoles are connected to the system (1-4)
SW CARDS switch = binary representation to the system of how many switch cards are connected to the system (1-16)
OPTIONS = doesn't do much, I think one changes the RS-232 port from DCE to DTE, and the other was for a pocket pager interface that was never developed.
RESET = resets system, power cycles ACC consoles
STATUS = changes operation of LED indicators LD1-8 on board. In one position, it will show the communication between the ACC's and the digital card. In the other, it will display a binary representation of system errors.


Moderated by  metelcom 

Link Copied to Clipboard
Forum Statistics
Forums84
Topics93,832
Posts636,785
Members49,649
Most Online5,661
May 23rd, 2018
Popular Topics(Views)
Today's Birthdays
bravesfan, cjvio, Cory S., Jack Scott, l.landeche, TexasD
Newest Members
devben, bubblegum, Carl Arnold, Marjan Shaw, KoolBreeze
49,648 Registered Users
Top Posters(30 Days)
ramo 13
pvj 11
Toner 9
dans 5
Who's Online Now
1 members (nortelvoip), 175 guests, and 17 robots.
Key: Admin, Global Mod, Mod
Contact Us | Sponsored by Atcom: Business Phone Systems | Terms of Service

Sundance Communications is not affiliated with any of the above manufacturers.
©Copyright Sundance Communications 1998-2023
Powered by UBB.threads™ PHP Forum Software 7.7.5