[MC-3808] Power components (buttons, pressure plates, detector rails, etc) sometimes output too short pulse Created: 24/Nov/12  Updated: 03/May/15  Resolved: 11/Oct/14

Status: Resolved
Project: Minecraft: Java Edition
Component/s: None
Affects Version/s: Minecraft 1.4.5, Snapshot 13w05b, Minecraft 1.5.1, Minecraft 1.5.2, Snapshot 13w24a, Snapshot 13w24b, Snapshot 13w25a, Snapshot 13w25b, Minecraft 1.7.4, Minecraft 14w05b
Fix Version/s: Minecraft 1.8

Type: Bug
Reporter: Kimitsu Desu Assignee: Unassigned
Resolution: Fixed Votes: 4
Labels: detector, minecart, rail
Environment:

Win7x64, Java1.7.0_04


Attachments: PNG File 2012-11-25_22.15.17.png     PNG File 2012-12-02_13.02.51.png     PNG File 2013-02-05_23.46.01.png     PNG File 2013-03-25_08.46.39.png     Text File crash-2012-11-25_22.16.02-client.txt    
Issue Links:
Duplicate
duplicates MC-56541 Redstone torches (and other redstone ... Resolved
is duplicated by MC-16044 Erroneous Button Output (1tick/5ticks) Resolved
is duplicated by MC-18450 Sticky pistons, even on a long pulse,... Resolved
is duplicated by MC-47237 Sometimes buttons will short-press in... Resolved
is duplicated by MC-4173 Buttons occasionally output too short... Resolved
CHK:
Confirmation Status: Confirmed

 Description   

Detector rails normally activate for ~20 ticks (depends on how fast the minecart goes) Sometimes though they randomly activate for something that looks like half of that normal time even if the minecart moves with the same speed.
To set up an experiment, create ~ 3x5 loop with some powered rails and a detector rail. Launch an empty minecart. Output the signal from the detector into a line of ~15 repeaters on 1 tick delay. Observe gaps in the output change in size sometimes.
P.S. This might relate to a bug which made a button to sometimes produce a shorter pulse, which I can't reproduce in 1.4.5 so far.



 Comments   
Comment by XeroOl [ 30/Mar/15 ]

duplicates MC-56541

edit:
and yes its fixed now

Comment by Kumasasa [ 11/Oct/14 ]

No answer for a long time, assuming fixed.

Comment by Mog (Ryan Holtz) [ 26/Jun/14 ]

Does this issue still happen in 14w26b? I recently committed a fix that removes random block ticking from redstone devices.

Comment by Galaxy_2Alex [ 21/Jan/14 ]

Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Comment by Kimitsu Desu [ 27/Dec/13 ]

Yes, it is.

Comment by irunor [ 27/Dec/13 ]

Is this the same thing that causes buttons to have random pulse lengths? (e.g. go to open an iron door and have to close before you even have the chance to move)

Comment by Kimitsu Desu [ 25/Mar/13 ]

Still an issue in 1.5.1

Comment by Anon Ymus [ 23/Mar/13 ]

Is this still a concern in the current Minecraft version (1.5.1)? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Comment by Markku [ 05/Feb/13 ]

I have no idea how the redstone stuff is being improved in the snapshots, but at least the timing differences used to be caused due to the random world updates randomly hitting the victim redstone device. They happen somewhat rarely per block, and if they need to also happen during a small time window, it is even more rare. Just my one cent that might even be worthless now.

(Maybe Mojang has excluded redstone stuff from those random world updates now.. maybe not.. or maybe they forgot just some specific devices from the exclusion.)

Comment by Kimitsu Desu [ 05/Feb/13 ]

Indeed, still present in 13w05b. You have to wait for it for like 10 minutes, but it's there. Same with buttons, I beleive...

Comment by Tails [ 05/Feb/13 ]

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Comment by Kimitsu Desu [ 03/Dec/12 ]

3x4 loop might be always on because of either directional stuff, or the way you start minecart, which is by pushing in your case...
It's still weird that the bug doesn't seem to show up though. I get it consistently in my setup. Should I post the world savefile?
Actually, it is downloadable at http://kimitsudesu.net/files/minecraft/sv.zip
The coordinates are shown on the screenshot.

Comment by Kumasasa [ 02/Dec/12 ]

Cannot reproduce.
Rebuilt your setup, but there's a discrepancy in your description:
You wrote in the text, the issue would occur with a 3 x 5 loop, but your screenshot shows a 3 x 4 loop.
With a 3x4 loop the output signal of the detector rail is permanently on

Stared for several minutes on the screen, but never saw a shorter pulse on the 3 x 5 loop.

Comment by Kimitsu Desu [ 25/Nov/12 ]

Attached a screenshot and a forced crash report.

Comment by Kumasasa [ 25/Nov/12 ]

Can you please press F3 + C for 10 seconds to force a crash and attach the resulting crash report here ?

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