[time-nuts] Affordable PoE 6-digit time displays?

Rob Seaman seaman at noao.edu
Mon Jun 18 11:54:52 EDT 2018


We have had good luck with several (8) of these SNTP POE units:
	https://www.amazon.com/TimeMachines-Precision-Digital-Clock-Digits/dp/B002R7KHAM/
Sturdy black metal case. I don’t think we’ve fried any in a year plus. I knocked one or two onto a carpeted floor from a modest height and it survived. 
Units are programmable (TZ, etc) via a flexible web interface and can display date instead of, or alternating with, time. As a handy setup feature you can double click a button in back to get it to scroll its DHCP address. Appears to have some features like countdown timer and options like an added relay to trigger alarms, but we haven’t used those. If your switch doesn’t do POE you’ll need a TP-Link or equivalent POE injector adding ~$15. They might offer a powered option, but not obvious why to prefer such to the injector option.
They have 4 and 6 digit models, two different sizes, and red/white/green. We don’t have any of the green, and generally prefer the red to the white. Like many LED devices the illuminated segments fade a bit as they are broken in, but can be programmed to a few different brightness levels, so start faint and crank them up later. Readable from across a pretty large room. The 6x2.5” are rack-mountable with a $15 kit; this unit is about 2-1/3U so will leave a little space above and below in a 3U section of rack.
SNTP seems sufficient to the job, at least with our reference clocks, and two units in the same control room set to UTC and local time will tick the seconds in lockstep with each other and external references to a small fraction of a second (hundredths or better).
Rob Seaman, University of Arizona
(No connection to the company.)
—
> On Jun 14, 2018, at 9:15 PM, David Andersen <dave.andersen at gmail.com <https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts>> wrote:
> 
> I'd hoped that ebay or aliexpress would yield a bounty given how seemingly
> simple these are, but I'm drawing a blank (and finding a lot of $300+ new
> options).  Anyone have a favorite source for either flat wall-mount or
> rackmount displays that will pull from an NTP/SNTP/whatever server?
> 
> (if wall-mount, PoE is optimal).  Used good.  Cheap good.  Looks good next
> to my random collection of antiquated time measurement gear provides
> amusement value but isn't really critical. :-)
> 
> Thanks!
> 
>  -Dave




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