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  1. #14
    Join Date
    Mar 2004
    Location
    Las Vegas, Nevada
    Posts
    1,647
    Nice find.
    Think I'd still be looking for loose connections.
    I'd still be banging my head.
    The views and opinions posted here are my own. They do not reflect the corporate policies of my employer and will most likely get me fired at some point.

  2. #15
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,057
    Quote Originally Posted by neumonic View Post
    Thanks for the explanation! Definately something I need to get into more and read about, I appreciate your response.
    http://www.embeddedsys.com/subpages/..._art_RS485.pdf

    Here is an explanation of RS-485 networks that's real technical. Page 2-3 talk about the importance of termination. I read it and kinda get it, but lots of computer geek stuff going on in the article that I don't get.

    To keep it simple all we need to know in the Refer field is that the network should be terminated...not so much why it should

  3. #16
    Join Date
    Sep 2008
    Location
    Vancouver , BC
    Posts
    266
    Thanks for the links guys.

    Phaseloss I think I like your explanation better then that article haha I tried to follow it but lots of computer lingo in there , im gonna try and re-re-read it.

  4. #17
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Quote Originally Posted by neumonic View Post
    Thanks for the links guys.

    Phaseloss I think I like your explanation better then that article haha I tried to follow it but lots of computer lingo in there , im gonna try and re-re-read it.
    If you're anything like me, you'll read it 4 or 5 times and not get it.

    Then, at 0200 some morning you'll jolt up out of bed and be amazed because somehow it suddenly makes sense.

    I think its called an epiphany....
    "The problem is the average person isnít tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and itís not in the movies they watch, and itís not in the few books that they buy, they donít get it" - Jack Canfield

  5. #18
    Join Date
    Sep 2008
    Location
    Vancouver , BC
    Posts
    266
    Quote Originally Posted by markettech View Post
    If you're anything like me, you'll read it 4 or 5 times and not get it.

    Then, at 0200 some morning you'll jolt up out of bed and be amazed because somehow it suddenly makes sense.

    I think its called an epiphany....
    Haha I know what you mean....I do believe I had me one of them epiphanies last night , but on a totally unrelated subject

  6. #19
    Join Date
    Jul 2011
    Location
    Utah
    Posts
    30
    Quote Originally Posted by markettech View Post
    I'm pulling my hair out on this one - looking for advice/input.

    Here's the story (its a little long winded) -

    Got called out to a store today on an E2 alarm - 'ESR Board #4 Device Offline'. The board went offline at approximately 1035 and returned to normal several minutes later. It went offline again twice more - all 3 failures occurring within 20 minutes of one another - and all returning to normal.

    Of course, when I arrive later in the day - there are no active alarms, and the device hadn't missed a beat since the hiccup earlier in the day.

    In poking around the controller, I see this particular board has been a problem child for quite some time with multiple call outs for this issue dating back to January 2011 - and as indicated by the maintenance log, has been changed 3 times since April of this year by the previous servicing contractor.....the most recent being September 18th.

    For point of reference, the controller is mounted in a back room, with a couple Hill/Phoenix pump houses sitting on the roof (low and medium temp). The LT system has a few MultiFlex boards, including 3 ESR's while the MT system also has a few MultiFlex, including 2 ESR's.

    I checked the daisy chain wires/connections obviously - also found and repaired a loose spade connector on the secondary side of #4's transformer.

    I tightened EMS electrical connections on rack, as well as electrical terminal blocks which feed power to fuse blocks/transformers....several connections were less than snug.

    The 460V supply wiring to the rack had been wire tied to a bundle of shielded cable and I noticed a few areas where high voltage wiring was running parallel with network cabling in the wire chases. Both of these issues were taken care of.

    I pulled, poked, prodded, and otherwise molested the wiring on the entire EMS side of the rack - but the entire time I'm on site, the friggen thing doesn't miss a beat - voltage looks good the entire time and she's communicating like a newlywed couple for the duration....so I pack out, do invoicing - and I'm outta there.

    I no sooner walk in the door at home, and monitoring calls me saying board #4 went offline again! (How they got a hold of my work number is also puzzling, but I'm focusing on one problem at a time right now....)

    #4 lost communication twice about half hour after I left - each time coming back online within a matter of a few minutes. It went offline a third time about 5 minutes before I got back to the store........and reestablished communication 2 minutes before I got to the controller.

    It's now dark on the roof and raining like a sumb!tch....and I'm back for a second time on a friggen board that refuses to cooperate with me and fail while I'm present.

    Scraping the bottom of the barrel of tricks, I double check baud rate and board address on all MultiFlex boards in both racks.

    I was concerned that maybe the factory installed daisy chain terminal points at the network cable plug could present a problem if there was a hairline crack at the top of the male connector or a loose/broken wire........so I cut them out and landed the daisy chain wiring directly into the network cable plug.

    An hour on site and no comm loss - no nuthin. Once again I type up a narrative and get signed out. Manager leaves (as by now the store has been closed for a couple hours) and I decide to look through my E2 manual to see what I may have overlooked.....which burned up another half hour.

    By the time I call monitoring to check out, the time is a touch after 0100. As I give the store # to the monitor-er......he tells me #4 went off line again at 0052.

    WTF!!!

    I need to be back there by 0600 and I'm not fuggen leaving until this baby is put to bed.

    Like I said at the beginning, if you've got any thoughts on this ('this' being the communication failure.....not the technician's lack of ability ) I'd be glad to hear them.
    Nice descriptive writing skills!!! was able to follow the whole way

  7. #20
    Join Date
    Sep 2006
    Posts
    151
    Is it the bottom board on a weathepack? Water damage will produce similar results as I have found.....

  8. #21
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Quote Originally Posted by Blackmira View Post
    Is it the bottom board on a weathepack? Water damage will produce similar results as I have found.....
    Nope, it was the last board in the daisy chain - in the condenser electrical panel.....not terminated.
    "The problem is the average person isnít tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and itís not in the movies they watch, and itís not in the few books that they buy, they donít get it" - Jack Canfield

  9. #22
    Join Date
    Sep 2006
    Posts
    151
    jumpers up?

  10. #23
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Quote Originally Posted by Blackmira View Post
    jumpers up?
    The terminating resistance jumpers were actually set to the 'in' position instead of the 'out' position on the MultiFlex board - or, as mentioned previously.....not terminated.
    "The problem is the average person isnít tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and itís not in the movies they watch, and itís not in the few books that they buy, they donít get it" - Jack Canfield

  11. #24
    Join Date
    Dec 2011
    Location
    USA
    Posts
    66
    CPC boards do not need to be terminated when they are first installed; however, they should be. The low voltage communication will work until it gets some age on it. I have seen them work for a couple of years and then start failing.

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