Taking a very long shot here...
Anyone familiar with the older tri-color Daktronics LED message boards? These are in the neighborhood of 15-29 years old, and long out of factory support.
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Taking a very long shot here...
Anyone familiar with the older tri-color Daktronics LED message boards? These are in the neighborhood of 15-29 years old, and long out of factory support.
I don’t know nothing ’bout fixing no message boards but there’s a lot of stuff on the web about them.
We have an issue with several of the 125 old boards installed here at the Airport. If I can find someone who knows something about them... with one exception... the Airport Authority might be willing to pay $$$ for their time and effort.
[ The one exception? The former site manager for the company that lost their contract to manage these and similar displays to my company. Let's just say that he burned a bridge or three with at least some of the C Suite crowd... I don't know the details, though I can guess, and I don't want to know ]
What specifically are you seeing with them, Ron?
An issue we resolved yesterday. Ironically, I was just about to update this post, too...Quote:
Originally Posted by N8YX
Short story: Few months back, a near lightning hit caused some issues in one of the airport's wiring closets (there are people who don't believe in proper grounding, but that's another story). Closet holds the Device Server that controls a section of the Daktronics LED boards in Ticketing. We originally thought the DS itself was affected... it wasn't. Then we thought we had a network issue... we did, but it turned out to be minor and actually unrelated. Then we thought we had a problem with the LED boards themselves. We did.
Boards are daisy-chained together into segments of about a dozen or so boards via RS422 cabling, and each segment then goes (also via RS422) to the device server; so each of the 4 COM ports on the DS runs a segment of LEDs.
So... we figured out which segment had an issue. Started at the end of the daisy chain (LED 58) disconnected the cabling until we found the one causing issues (response time on a PING to the DS was 60 - 3000 ms instead of 1 - 2 ms). Powered down the culprit (LED 49). Looked at what modules on the board we could change. First up was the RS422 input/output board. Changed it to a 'new' one from stock, powered the board back up, no more issues. (Yay!)
Would still like to talk with an 'expert' on these things. We have 3 boards that don't respond to commands from the control server, would love to get them fixed. We know more now that we did, but we still don't know enough. And it didn't help that the previous administrator of these boards didn't leave us any documentation or notes... he took it pretty personally when his company lost the contract renewal to my company.
Having dealt with similar stuff (RS-485) in a previous life, I'll offer the following:
Transients on those long cables will kill the bus transceivers, and EMI protection was probably too costly to implement. Take the 3 affected boards and find the 422 connection points (physical bus to transceiver IC). Then identify the driver ICs, remove, replace and test.
FWIW, I replaced the 1488/1489 RS-232 pairs in a TON of packet modems over the years, and my old employer's repair depot did similar with anything connected to their product's backplanes. If you want I can help identify the ICs in question.