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12 Devices - 8 IR ports - help!!

craigcraig Junior MemberPosts: 14
Hello All,

We curently have the AMX NI-3100. We started with 8 set top boxes .. we now have 12.
The 8 IR/Serial ports are all in use to control the existing 8 set top boxes.

Will we need to purchase another AMX controller to control the additional 4 set top boxes or can we use some of the other existing ports (Relays, I/O, PORTs) on the controller for the additional IRs.

Thanks in Advance,


  • Andrew G WelkerAndrew G Welker Junior Member Posts: 124
    Does your NI-3100 have ICSNet? If it does, you can just purchase 2 NXS-NMS card cages and 2 NXC-IRS4 cards. If you don't have ICSNet, I would first try and find an old Axcent master on Ebay that you can put into slave mode and use the IR ports that way via AxLink. If that doesn't work, then probably the next most cost-effective solution would be to upgrade to a NI-4100 & 2 NXC-IRS4 cards that can go into the built in slots in the 4100. The last resort would be to get a NI-2100 and do M2M communications.
  • mpullinmpullin Obvious Troll Account, Marked for Deletion Posts: 949
  • John NagyJohn Nagy CineTouch Product Manager Posts: 1,640
    If your sources are not all identical, you can "stack" several in a single IR port, and run as many as three IR emitters from each port. We've done that for years, you will not "burn out" the port or have weak IR.

    We use a scheme with an offset, so one port may have the DVD using IR channels 1 and up (normal use), then the DVR has an offset of 100, so it's commands start at 101, and a display might be on the same channel with an offset of 200 so its commands start at 201.

    Obviously, the devices so stacked can't be the same, all emitters will blink PLAY, and all that see it would respond, not just the one you mean.

    The other benefit of a stack is reduction of required wires, valuable in retrofits where you don't get to choose. One IR pair from the rack can run a TV, a local BluRay, and maybe something else too.
  • John NagyJohn Nagy CineTouch Product Manager Posts: 1,640
    mpullin wrote: »

    Or for the same price, their new IP based unit that also doe 2-way IR on 4 in and 4 out.
  • John NagyJohn Nagy CineTouch Product Manager Posts: 1,640
    Parallel wiring. We've done as many as 4 and have not seen any reduction in effectiveness. But we try not to go past 2 just for neatness and conservative design.
  • champchamp Junior Member Posts: 261
    Stacking IR ports is an issue if both devices are the same brand and type which i think is the case if you are using all set top boxes.
    A way around that is running an IR port into some relays and switching it, of course the programmer will hate the designer.

    If you stack IR ports and wire them in parallel you may have issues with one not working due to having a higher overall resistance so it is best to wire in series.

    Stacking IR is also an issue if you want to send multiple commands to all devices simultaneousl.
    For instance I have done systems in clubs where lots of TVs need to turn on and go to preset channels in the morning and each TV may take up to 12 IR pulses (to turn on, go to a channel, select teletext, enter the 3 digit teletext channel, select sub channel, enter the 4 digit sub channel), not surprisingly the customer is not always happy with it taking a few minutes to turn the system on but it all comes down to what they are prepared to pay for.
  • viningvining X Member Posts: 4,368
    I would also suggest the AXB-IRS4 but there's also the iTach from Global Cache: http://www.globalcache.com/products/itach/ip2irspecs/ which should work too.

    Since the OP mentioned 12 STBs stacking isn't really an option and the extra coding required to try and use relays for routing makes the above 2 choices alot less exspensive. Do youself and AMX a favor and just use the AXB device.
  • John NagyJohn Nagy CineTouch Product Manager Posts: 1,640
    "Set top boxes" need not have to mean identical devices, my cable box, Boxee, Roku, and DirecTV are all "set top boxes."

    While a relay management could be done, yes the programmer will hate it, and timing will be critical. Too complicated.

    Your statement about not working in parallel and better in series is debated by 15 years experience by dozens of our dealers in hundreds of jobs. Series would cause a voltage drop across all emitters, possibly bringing the firing voltage too low to operate. Have you ever tried this yourself? In series, you also have multiple failure points, any connection lost kills them all, like old Christmas tree lights. Several IR emitter companies make multiple emitter kits for this purpose, and they are parallel.

    Regarding "simultaneous" use, there is imperceptible timing difference for ordinary use - milliseconds. Poor selection of items to stack can of course result in poor performance.
  • viningvining X Member Posts: 4,368
    John Nagy wrote: »
    "Set top boxes" need not have to mean identical devices, my cable box, Boxee, Roku, and DirecTV are all "set boxes.
    That may be technically correct or not but to me an STB is a digital tuner box, cable, sat or ota astc. I would never describe Boxee, Roku or any other IP streaming device as a STB but i am a bit backwards so maybe i'm just out of sync with reality.
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