PlanetZ forums - scopeusers.com

Hi all,

for everyone's good, could users of multiple Pulsar II's please report whether you use 1 or 2 STDM cables & related problems you've had etc. Post your computer setups too. IE: Mobo/chipset, processor etc. That way hopefully we can build a picture as to why some users can run 2 or 3 Pulsar II's with 2 STDM busses and some can't.

Thanks

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<font size=-1>[ This Message was edited by: Shroomz on 2005-11-22 03:40 ]</font>

anyone ?

hi,

according to creamware, you can only cascade three scope cards per via STDM cable methink,

cheers,
didier

<font size=-1>[ This Message was edited by: astroman on 2005-11-23 07:38 ]</font>

previously posted by astroman

" yes, but some have more than one connector "

indeed !! could work with four cards, however functionnality is not garanteed under four. I was thinking about buying an additional card my self, as I already have three installed,

cheers,

didier

I think the thrust of the question is if you can use (to any advantage) more than one S/TDM cable.

My memory is that the SFP platform is optimized to use only one S/TDM cables, and you should be using the one closest to the I/O bracket.

The others connects are part of the Analog Devices reference design. I think Paul Tanti (spectacles, testicles, wallet and watch --for the British readers... if you don't get it, forget it) once told me that using more than one cable can actually degrade your timing between cards as it introduces more overhead. Never tested it myself.

If anyone has better info please correct me.
Sam

<font size=-1>[ This Message was edited by: dehuszar on 2005-11-22 14:19 ]</font>

One STDM cable ? .... That seems to be contrary to what Wolf states in the Scope Pro users' STDM buss thread. He reckons the more busses used the less you'll get *the* error. I'm sure I actually remember Wolf saying on an older thread (although i couldn't find it) that you would double your STDM connection count by using a second buss (can't remember the numbers, sorry

Wolf ?

<font size=-1>[ This Message was edited by: astroman on 2005-11-23 07:37 ]</font>

<font size=-1>[ This Message was edited by: astroman on 2005-11-23 07:37 ]</font>

but as i said, smaller boards need more connections than bigger ones when doing the same job....

<font size=-1>[ This Message was edited by: Shroomz on 2005-11-23 08:59 ]</font>

<font size=-1>[ This Message was edited by: astroman on 2005-11-23 07:38 ]</font>

<font size=-1>[ This Message was edited by: Shroomz on 2005-11-23 09:00 ]</font>

On 2005-11-23 03:25, Shroomz wrote:
...but as i've had to do in the other thread because of your waffling, i'm forced to do it here too

I've made a little space, but certainly not because you were forced to do something
your ignorance is just one step beyond, so be happy with your empirical collection
you've been told that it's a problem of the small boards and apparently Modular in particular.
You will end exactly with that conclusion.

cheers, Tom (beam me up...)

Astroman, read very carefully :

Lets_Gather_Some_Facts_About_using_Multi_STDM

.... connections

It's for everyone's good (including yours)

You say i've 'been told' ... whoooo we'll see

An interesting point is that MD69 posted on the other thread that he has the STDM connection count problem with only 50% DSP load on larger cards (PowerPulsars) & he's using multiple busses. I would imagine that this could be improved if he used *all* of the busses on his PowerPulsars, but regardless, hopefully you'll see my point & also the point of these threads......... To build a better picture for us all of STDM use & experience. Everyone with relevant information is of course welcome to post....

Thanks

MD69, can you optimize your project after that message? if so, does that help?

to answer the question :

my system has worked great with a scope + P2 (21 dsp) :
mobo : Asus P4G8X dual ddram
dram : samsung
Never had trouble with a clean installation.
As for the STDM, remember to use the extreme connections and not that of the middle (of course when usisng 2 cards !)

Thanks bill3107,

I wonder, do you use 2 STDM connections & do you ever get the error saying you've run out of connections from one card to the other??