Train describers (DAISY) and 3 unit

Could someone expand DAISY for a bear of little brain, please? I'm guessing the D is possibly Digital meaning it could be Digital And Illuminated Signs Yah!

Aha! TVM. Is that an acronym that has evolved or was it used from introduction?

Here in Amsterdam, my Metro route (50) is supposed to be 3-car during the peak and daytime but quite often is short-formed. On platform signs, after the train has left the preceding stop, the estimated arrival time of the train is replaced by a pictogram of a two- or three-car train as appropriate, allowing people to move to the appropriate place on the platforms. I've often thought that this would be useful on the DLR.

Hmm, that's cheating! I think Reg's answer fits best, the Docklands part is a back-formation IYSWIM.

Oslo's system for its Metro (called SIS - translates to Real Time Information System) manages to do different numbers of cars - trains are coupled to permanent three car sets but can be run up to four three car sets I believe. Not that there are sufficiently long platforms anywhere though!

farm4.static.flickr.com/3458/3264881596_cb5ea51216.jpg?v=0

This image is of a six car train - shown as two cars on the SIS screen. The next one due (over 15 minutes shows as a clock time based on time table, traffic level and normal running time all put together in one number I believe!) is a three car train.

(I fail to see how this is relevant though!)

I do believe the DLR also had something called WANDA however i'm not sure if this was another information system.

WANDA was the system that provided similar arrival and departure data by station, but to WAP-enabled mobile phones.

Thanks, always did wonder why a pictures of trains appeared on the departure boards in Amsterdam. Obviously not spent long enough standing at Waterlooplein and Station RAI to work it out for myself!

I've uploaded a rather rudimentary 'simulation' of how such messages currently look, and how I think they ought to look:


DLR Display Options by Zone7, on Flickr

The way I understand it, the DAISY displays work by scanning from bottom-to-top, both 'big lines' together - i.e. as the lowermost pixel line of the top 'big line' is being written to the LEDs, so is the lowermost pixel line of the bottom 'big line'. I don't know about anyone else, but I can see the scanning quite clearly and I see them scanning this way, both lines in sync with each other. I have always supposed that the reasoning for the scanning working this way is so that scrolling text slopes to the left instead of sloping to the right, as it would if scanning top-to-bottom and also, dividing the scanning area into two segments is so that the required freshrate could be maintained using the technology of the day. Presumably if the whole display field was being scanned in one go, too much flicker would result in timing the scans in line with the desired scrolling speed for scrolling messages. To get the scroll speed right, remember, the scanning/refresh rate has to match, so that the message can be moved along one pixel for every refresh. Otherwise, you end up with a very jerky, jagged effect on scrolling messages, which can be seen on the first-generation JLE DMIs and indeed some of the B09 stock's internal displays which appear to be wrongly configured (and do two screen refreshes per pixel scroll).

Scrolling the second line of small font shouldn't, I would have thought, be a problem, because all that needs to happen is that the second line is nudged along by one pixel every refresh. The refresh rate would be the same, and the scan pattern would be the same - except that during the refresh of the lower 'big line' (the lower half), the refresh is drawing half of it ("NO LIFT SERVICE") in the same position as the last field, and drawing the other half of it (the scrolling part) one pixel to the left. The resultant scrolling effect would still be as smooth as if it were a big line.

That said, I understand about the readability issue, but then given the frequency of display of these messages, I'd say that partly counteracts that issue, which is the original point I'm making - they appear far too often.

Alternatively, you could have the scrolling message taking up the top line in big font, then show Next Trains 1 and 2 in small font beneath - again, not ideal in terms of readability, but better than not showing the Next Trains *at all* (as now).

Or perhaps, DLR could resist the temptation to cram so many damn scrolling messages in in the first place! Lifts out of service, granted. Closures next week, granted. Closures in two weeks' time, closures on 5 or 6 LUL lines, and the fact that CCTV is monitored by the BTP, a bit overboard I think. The latter category of information is given out over the PA system verbally almost every 90 seconds now, so I think visual confirmation is unnecessary. OK, so there's the DDA to consider, but does that create a legal requirement to turn Next Train Indicators into constant subtitling systems for every single announcement uttered?

Just for the sake of correctness, the platform displays are PIDs, Daisies are the monitor based displays usually on concourses.