PCI RJ-45 ports seem to be read only

Discussion in 'C-Bus Wired Hardware' started by Justin, Sep 4, 2009.

  1. Justin

    Justin

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    Sorry, this question should be directed to tech support but they are closed and we are really trying to get this working today.

    We got one of CISCO's mediator products that speaks just about everything to make a quick C-Bus to BACNet to ModBus bridge. It connects via RS-232 to a PCI. When the installer plugs it into the DB-9 port on the front, everything works fine but when we try and use the 2 RJ-45 ports on the top we are able to read data coming across the wire but not issue commands. Are the two, RJ-45 ports at the top of the unit read only?

    I would just have him use the DB-9 perm. but I originally got the unit to talk to the powerlink panel and want will have to order another unit if those RJ-45 RS-232 ports are in fact read only.

    Justin
     
    Justin, Sep 4, 2009
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  2. Justin

    Lucky555

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    The first thing I can think of is to check the pin out (wiring) on your RJ45. C-Bus PCI's like most RS232 devices only use signal common, TX, RX lines, sounds like you are crossed on one of those.

    I will tell you a little story - In January 2007 I got onto a big Flying Kangaroo (Qantas 747) and did the big scary flight over the Pacific to Los Angeles, then into a little clunky American Airlines Saab 340 up to Santa Barbara. In my bag was a PCI, CTouch Mk1, Saturn and Neo key input units. I handed them over to a very clever man named Ed Richards - CEO of Richards Zeta, home of the RZ Mediator. Prior to this I had organised for an old chum "Uncle Sam" to send across a couple of 110 volt output units to the RZ gang.

    The clever chaps at RZ built the gear up into an impressive demo unit and used this to build and test the Mediator - CBus driver. Now uncle Ed as I call him, has sold to CISCO as they get serious about getting into buildings with their Connected Real Estate push. It is interesting to hear that, that effort back in 2007 has paid off and C-Bus is further established as one of the very best lighting and control technologies in the world.

    PS. Santa Barbara is a beautiful place.

    PSS. Don't forget, play around with your pinnouts and you should be fine...;)
     
    Lucky555, Sep 5, 2009
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  3. Justin

    Justin

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    Wow, thank you for the quick history lesson on the mediator. I did not know it was not originally built by CISCO. It really will be a wonderful addition when we get it to work.

    You may be correct about the pinout problems. The diagram is a bit confusing. The way I understand it it looks like you loop pins 7 and 8 into each other and you loop pins 1 2 and 3 together as well. I did not do this because it did not make sense but perhaps I need to.
     
    Justin, Sep 5, 2009
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  4. Justin

    Lucky555

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    When I was responding to your post I actually had serial connections for the PACA in my clouded mind.

    Stick to the diagram for the pinout, what you described might be looping / bridging out the flow control lines...

    If you are still stuck can dig out a wiring diagram...

    Let us know how you get on...
     
    Lucky555, Sep 5, 2009
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  5. Justin

    Darpa

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    Here's the pinouts for the RJ45 RS232 ports on the PCI.
    If I'm reading the diagram below correctly, then pins 123, and 78, are wired together internally, to fool other devices plugged into the PCI.

    Please note, both the RJ45's, as well as the DB9 on the front, are all wired in parallel, which means you will need a second PCI for your application as well.
     

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    Last edited by a moderator: Sep 5, 2009
    Darpa, Sep 5, 2009
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  6. Justin

    Justin

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    So you can only use 1 of the RJ-45s or the DB-9 but not both RJ-45s with nothing plugged into the DB-9?
     
    Justin, Sep 5, 2009
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  7. Justin

    Darpa

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    I could be wrong, but as far as I can tell, yes, you can only use one of the 3 ports at any one time. I believe that you can have devices plugged into all 3 at the same time, but only one of them can be turned on and communicating with the PCI at a time.

    Have a look at the diagram I posted above, it shows all 3 ports on the PCI as being hard-wired together in parallel.

    For more information, I'd recommend looking at the Installation manual for the 5500PC, located here:
    http://www2.clipsal.com/cis/__data/page/428/5500PC Installation Instruction2.pdf
     
    Darpa, Sep 5, 2009
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  8. Justin

    froop

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    RS-232 is a strange beast. Not so much because of the specification, but because of the way so many manufactures build their devices - ie, so they don't necessarily meet the RS-232 spec, but just good enough so that they work with it.

    RS-232 is most definitely a point-to-point protocol. You can only have one device on each end of the wire. (Ok, there are some exceptions. See foot note). In theory, if you have devices plugged in and turned off, they should not interfere with the other devices. But there's no guarantee.

    --
    Footnote:
    It's often handy, and perfectly acceptable if wired correctly, to have a single trasmitter but multiple receiving devices. But having multiple devices transmitting data, you'll need to pretty lucky to get it working properly, nevermind reliably.
     
    froop, Sep 5, 2009
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  9. Justin

    ashleigh Moderator

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    The RJ and DB9 connectors are MOST DEFINITELY wired in parallel. You may use any one of them for a given signal.

    You can for example use TX on the DB9 and RX on one of the RJ's, and other such exciting combos. But parallel wiring is parallel wiring.
     
    ashleigh, Sep 6, 2009
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