Connecting LSI MegaRAID 9260 to SAS Backplane

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I'm looking at building a new server using an LSI MegaRAID 9260-4i card
and a Supermicro SC743TQ-865B-SQ case. What do I need to connect between
the RAID card and the backplane to get the case LEDs working? They're
supposed to be able to indicate when a drive fails. I know both the card
and the backplane have a I2C connector. Do I need an I2C cable? I've
also seen something about a sideback connector on the backplane.

Re: Connecting LSI MegaRAID 9260 to SAS Backplane

David wrote:
Quoted text here. Click to load it

Try JT-12 header in the picture on PDF page 44 and text on PDF page 46. It
looks like there is a 2x8 block of pins, enough to drive 8 LEDs on the
eight port card. So presumably, on a four port card, the header pins would
only be half populated. I would expect to see 2x4 pins and 2x8 holes, with
the remainder of the holes lacking pins. There should already be a series
current limiting resistor in each LED drive circuit, so you just connect a LED
across the pins. If it doesn't light during any "lamp test" phase of card
try rotating the LED contacts 180 degrees and try again. If you're lucky,
there may even be polarity info near the header, or even channel numbers,
so you can tell which LED is which. Some companies are clever enough to
use full color silk screens, so that some of the pins will have red legend
around them, others black legend, to indicate (+) and (-).

     +---+ +---+
     |X X| | X | JT10
     |X X| | X |
     |X X| +---+
     |X X|
     |X X|
     |X X| +---+
     |X X| | X | JT9
     |X X| | X |
     +---+ +---+

So the JT12 has room for eight LEDs, with the pins going across in pairs.
One LED would connect to two pins oriented this way. The only thing not
explained in the manual, is which pin is (+) and which pin is (-). The
LED will not be damaged, if you reverse it. As long as computers continue
to use 5V drive for LEDs (or less) and 5V reverse tolerant LEDs, there
is nothing to worry about. Just reverse the LED, if you're convinced it
isn't lighting when it is supposed to.

     |X X|  Enough for one LED

Presumably, I2C is for some more intelligent form
of control or monitoring. It wouldn't be a first choice
just for LEDs. The manual mentions "IPMI Enclosure Management"
via an I2C header.


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