Talk:Daisy chain

Comment

"Daisy chaining was a characteristic of RS-485, of Apple Computer's LocalTalk, and of various industrial control networks; also often used to describe Thinwire Ethernet (10base2)."

Technically, a Cheapernet (10base2) is a broadcast medium where any participant reads the same signal (modulo signal traversal time on the cable). A Daisy Chain is exactly not a broadcast idea but the idea of a signal switched from one node to another through some means of logic. It is generally not electrically wired as one electrical signal for the whole chain but only for the connection of two adjacent nodes.

A positive example of Daisy chaining in computer networks is Token Ring, where each node (if not bypassed by a switch) can intercept the signal (but generally should only do when injecting a new packet with the token free flag cleared).

Picture

The picture appears to be of ivy with daisies stuck in it, not a daisy chain constructed as described in the intro. -- Beland 20:24, 12 February 2006 (UTC)

Split

I'm not so sure this article is in need of a split. I personally don't foresee these various sections getting much bigger than they currently stand. Computer engineering maybe, but the rest, not likely at all. SchuminWeb (Talk) 22:43, 12 February 2006 (UTC)

sexuality and verifiability

It would be good to have some references for the sexuality section, as people keep extending the definition. --njh 04:42, 28 February 2006 (UTC)

I agree... we do need references for this, or else the section should probably get zapped. SchuminWeb (Talk) 18:49, 1 March 2006 (UTC)

You are not requiring references for the other sections; are you sure there is no ulterior motive here?Nickrz 19:27, 28 March 2006 (UTC)

I expressed my ulterior motive: I'm getting sick of reverting the constant thrash in this section. The other sections seem uncontroversial and thus don't really need references. I personally have no issues with other people's sexual behaviour - we're all weird in some way. I might just unwatch this page and let others fight it out :) --njh 01:12, 29 March 2006 (UTC)

I agree with you - that section was getting a little weird. So in an effort to lay the controversy to rest, I Googled the term, being careful to exclude Wikipedia mirrors. I came up with this URL, which confirms the definition. SchuminWeb (Talk) 18:34, 29 March 2006 (UTC)

   That link has apparently been reclaimed by the site's connectivity provider, and stocked with ads. But the legend's existence at an early date is verifiable (even if the phenomenon is not), near the upper righthand corner of this WMFndn image. This version is a bit larger on my screen, and it may be that even the resolution of the original B&W image has been improved when it was colorized. BTW, i see the man himself made it to a documented age of 80; i presume he is now pushing 84, but no longer granting interviews.
--Jerzy•t

Daisy-chaining in Electrical Engineering

In the "Electrical Engineering" section, daisy-chaining is referred to as connecting devices in parallel. I believe this should read "series", not "parallel".

its probally not series (in the electrical meaning of the word). From an electrical point of view its generally either paralell (in power systems and older/simpler communications channels) or a totally seperate interface for each link (in higher speed communications channels). I've just done some fairly heavy rewriting Plugwash 17:44, 16 August 2006 (UTC)

I suppose it depends on your point of view whether the electrical bus style networking is in series or in parallel. With a typical 2-conductor shared-bus network, all the "A" wires in each length of network cable are in series from one end to the far end. (Also, the other wire in each cable -- the "B" wire -- is also in series from one end to the far end, and twisted around the "A" conductor). However, each node (computer) connects to both the "A" wire and the "B" wire, so each node is technically in parallel with each other node.

Is there a standard terminology to distinguish between the 3 ways that Plugwash mentions for hooking up a bunch of devices?

• Electrically a electrical bus: systems with metal-to-metal contact from one end to the far end, like Localtalk, and systems that use a vampire tap to all connect to the same piece of metal.
• ... what is this called? ...: a regenerated bus like MIDI or delayed-and-regenerated like daisy-chained Serial Peripheral Interface Bus or systems that use a network hub or other repeater. I suspect some people use "daisy chain network" to *only* mean this kind of system.
• electrically a bunch of independent point-to-point (telecommunications): a bus like USB or FireWire and most fiber-optic communication systems (perhaps using packet forwarding or bridging (networking)).

In particular, the sentences

The classic, simple way to prioritize interrupts or bus access was with a daisy chain. -- bus (computing)

the easiest way to add more computers into a network is by daisy-chaining, or connecting each computer in series to the next. If a message is intended for a computer partway down the line, each system bounces it along in sequence until it reaches the destination. -- Network_topology#Daisy_chains

doesn't make sense if the "daisy chain" is a metal-to-metal electrical bus. I suspect some people -- such as the writer of that quote -- think that "daisy chain" only includes regenerated buses, not metal-to-metal buses. (They might say Localtalk is "electrically a star, but physically appears to be a daisy chain"). --75.19.73.101 (talk) 08:41, 10 December 2007 (UTC)

Localtalk

localtalk is clearly physically a daisy chain but electrically is it a simple bus (like scsi), a regenerated bus (like midi) or two essentially separate interfaces with higher level forwarding between them? (i wrote this some time ago as i was restructuring the article but commented it out because it wasn't a usable paragraph in that form, someone removed it from the article so i'm putting it here instead) Plugwash 16:54, 6 September 2006 (UTC)

Localtalk is electrically a simple bus (bus network) (like scsi). It has metal-to-metal contact all the way from the termination resistor on one end of the bus to the termination resistor on the far end of the bus. --75.19.73.101 (talk) 08:41, 10 December 2007 (UTC)

Expanded edit summary

(First time 'being bold'... feel free to put me in my place if needed.) Did some big rearranging in the "electrical and electronic engineering" section. Still needs a lot of work. While I'm looking at it, the headings for four-equals-signs of depth (SCSI and MIDI) appear correctly in the TOC, but aren't showing up as 'lesser' headings (sub-subheadings of 'signal transmission') in the text itself... is this standard behaviour or did I mung the markup? I also think the section is encyclopedic enough to warrant citing; added template. Still needs some elimination of use of 'refers to' (see Wikipedia:Guide_to_writing_better_articles#Use_of_.27refers_to.27). Restructured as needed to eliminate run-on sentences and hard-to-understand grammar. Added a bit of content to make existing content easier to put in context. Wikified, wikilinked, fixed spelling and punctuation in places. Joel D. Reid 05:32, 23 September 2006 (UTC)

Daisy chaining in computer architecture

In a coursebook I read that daisy chaining is also a technique used to decide which I/O device generated an interrupt after the microprocessor received the interrupt. If someone knows more about this, please add it to the article. --Bernard François 14:49, 13 January 2007 (UTC)

If you want to, you can be bold and add the info yourself, especially if you cite sources like the coursebook you mentioned. If you have any questions about how to, you can ask me on my talk page or here. delldot | talk 17:09, 14 January 2007 (UTC)

midi section is a bit hard to read

"suffers from asymmetry due to the opto-isolator distorting the signal with each item in the chain" --- what exactly does that REALLY mean in english? how does that impact a real life senario? Joshsteiner 20:04, 13 February 2007 (UTC)

Opto-isolators have an article, and their application to MIDI (or other sensitive circuits) should be fairly clear. That said, actual MIDI-related, circuitry-symmetry concerns are not covered here, nor even in the MIDI article.
So, to answer your immediate question, the more devices one puts into any sensitive system, the higher the risk of signal distortion. In this case, optical isolators are necessary protection but act as yet another point of failure and can introduce loss of signal integrity.
To answer your, methinks, implied question, "why is this section unclear?" I agree that the content on symmetry and isolators is approaching techno-babble as written, so I flagged it with "{{cleanup-jargon}}" — Joel D. Reid 07:54, 27 May 2007 (UTC)

Computer software

A Daisy Chain is not a package management technology. At most, it is a pattern for software installers. Fatespeaks 22:25, 20 May 2007 (UTC)