MC question that got me confused. (1 Viewer)

[stoydgen]

hey guys i got this uestion in my trial, and it confused me because i thought there was more than one answer. here it is:

The answer is A, but cant a parralel cable also be used to daisy chain peripherals?

Please explain hehe.

Cheers!

 

[CrashOveride]

hmm that was also in mine, u did the same trial as me perhaps =p
i said A because thats USB cable, and i know for a fact u can use USB to daisy chain...hmm someone else can come up with a more detailed description i hope

 

[stoydgen]

heh see i put in c, the parralel cable, because well... thats the daisy chain setup thats on my old school computer (printer to scanner to computer). It really pissed me off that they could only mark one of them right, becuase clearly they can both be used :s

 

[konggo]

its not use cable there talking about the usB connection..ie it has one side usd the other look slike a small thing...they might use in external ADSl moderns like mine.

 

[stoydgen]

Or it could be a USB mini port. Hehe umm while that could be used to daisy chain, the parralel also does that? so why aren't both right?

 

[rckl]

if C is wrong, i believe they also looking for the faster medium to transfer data
and that is USB

 

[stoydgen]

Shouldnt they specify that then if they are looking for the fastest medium? I'll stick to the USB cable if i am asked such a question, but i just don't get why they have 2 suitable answers, but only one is correct.

Cheers Guys, n good luck on friday!

 

[rckl]

yeah.. probably the best answer is to choise USB.. + USB 2.0 is 480kbps, if i am not wrong. but paralla is only 8 bit.

 

[stoydgen]

Yeah USB it is

 

[LeftrightOut]

What is their definition of daisy chained?

If it's the traditional definition of daisy chain it would mean PC->A A->B B->C C->D then it's parallel cable all the way.

USB requires hubs to be able to (very loose definition of) daisy chain devices so you'd end up with PC->hub->A/B/C. Any USB device that has the capability to plug other devices into it (some monitors for example) contain a hub within themselves that split the signal to other devices and it doesn't pass through the A device itself to get to B it goes through the hub.

USB can have tiers of "daisy chains" with the hubs (not peripherals) forming the chain but only parallel can have serial daisy chains of peripherals which is what the question seems to be asking.

There also doesn't seem to be any mention in the question regarding speed so make sure not to go answering things they aren't asking for.

Of course it depends on what the person who set the exam thinks a daisy chain is but the way it is worded C would be the correct answer.

 

[rckl]

but urrmm... if a USB device have an output port to another hardware, it will work in the similar way as paralla .... but so far... i haven't see one yet.... that y they introduced USB hub which work in the similar way?

 

[LeftrightOut]

but urrmm... if a USB device have an output port to another hardware, it will work in the similar way as paralla .... but so far... i haven't see one yet.... that y they introduced USB hub which work in the similar way?

yep that's right, but there are some people with weird ideas about just what a daisy chain is.
Firewire is another example of a standard you can daisy chain, that is you can grab 3 firewire devices and plug them into each other without a problem and no need for a hub. USB can't do that, there is no way to connect more than 1 USB devices to 1 USB port without a hub being involved.

 

[rckl]

yupz.. true....
now i'm gettting confused.. hehe sorry

what is the difference between a switch/hub and a USB hub?

both different hubs work in the similar way?

 

[LeftrightOut]

Switches,hubs and USB hubs

A USB hub simply passes along signals from one USB cable down several other cables.

A network hub simply passes signals down form one networks cable down several others that are connected to it. it does that in a collective fashion so when you send somehting everyone gets the same data even if they didn't want it, so it's not very efficient.

A switch passes signals down from one network cable down a specific other one. Depending how smart the switch is the traffic from one computer will only go to the destination it was meant to and not all the other computers.

 

[stoydgen]

lolz so what you're saying is the parralel cable IS the most technically correct answer? Because i didnt think USB coz you need a hub to keep connecting devices to one port. I think if one of these popped up in the test, they would have to accept both answers?

Because they can't mark the guy wrong if he's using the tradition definition of daisy chaining?



Maybe Mr blackwel can help us clarify?

 

[LeftrightOut]

yes C is the most technically correct answer since they asked about daisy chaining peripherals which would mean one to the other, which USB can not do. Using USB you are daisy chaining hubs not peripherals.

At least that is what the TAFE answer would be, I hear those high school and BOS folk have some weird ideas sometimes

 

[rckl]

alright.......cool.. thank you...

 

[CrashOveride]

Leftrightout:

Can you go here:
http://www4.boardofstudies.nsw.edu....&testUUID=24F26D4B-D8B8-5760-1A37CDFFB0BB825E

And for Q13, can you explain to me the logic behind that. I can deduce that answer by deduction but why is it that port B can use longer cables than port A ?

 

[LeftrightOut]

USB vs what appears to be serial

USB is 5 metres per cable max
Serial is 30 metres per cable max

You can extend the range of USB by using hubs and get a max of around 30metres using 5 hubs. But that would not be using one cable.

Google would have told you the same in less time