Dell Poweredge SCSI backplane questions

Question

I recently bought an internal Dell two disk Hot Swap chasis from E-Bay (item URL: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=8712429247). I am thinking of using this in something other than a Dell Poweredge server (it came out of a Dell Poweredge 6400 series machine). I have some questions:

There are two 68-pin SCSI connectors -- do I need to connect to both connectors to use two drives?

There is also a 10-pin header, which seems to be meant to be connected to a Dell Poweredge motherboard (or interposer board or to another Dell SCSI backplane, depending). I am assuming that this connector/cable relates to various configuration options, such as SCSI ids to use. I cannot find documentation on this connector, specificly a pinout (so I can make my own little board to plug it into).

warwizard55 · Answer

Hi Robert,

The two 68 pin connections are SCSI A and SCSI B, the BP will be treated as a 1x8 if only SCSI A is used, and will split into a 2x4 if SCSI B or both connectors are used.

The small connector is for the embedded system management (ESM), allows ESM F/W to be updated and passes serial data about the SCSI termination voltages, regular voltages, and temperature readings to the system board's ESM. Not essential for SCSI operation.

I do not have a pin out or any timing diagrams or signal definations that I can publish.

warwizard

RobertHeller · Answer

I've just hooked the backplane up to a SCSI controller and it seems to work just fine with the small connector unconnected. I connected both SCSI connectors to the SCSI bus and that seems to be what it wants. The only remain issue is SCSI ids -- by itself it numbers the drives 0 and 1, with 6 being used for the cage's management board. I suppose there is nothing I can do to change the SCSI ids (outside of using it in a Dell poweredge system). Thanks for the info though.

RobertHeller · Answer

I have a another question about these Dell Poweredge SCSI backplanes.

Is there some way of changing the SCSI IDs? I'm thinking of adding this unit to an existing system, which already has devices using the SCSI ids the backplane seems to default to on its own and I am wondering if the unit can be configured to use other SCSI ids or not (I can change the ids of the existing equipment if necessary).

warwizard55 · Answer

Hi,   Only the very oldest of Dell's backplanes could have the SCSI ID changed, for the ones you have, the ID's are hard wired. warwizard

DRaine3 · Answer

I just picked up the same type 1x2 drive cage (also from Ebay) referenced in the original post and would like to install it in my 6400. While the PLANAR connector for the system board's ESM is not essential, there does not even appear to be a place to connect it if someone did want to use it. There is a connector of the same type on the power supply paralleling board, but it's missing a pin and it doesn't appear to be labeled for such use. Is there a connector somewhere I am missing? Thanks in advance for any replies.

DRaine3

hemerich · Answer

You could use it in a system that already uses those SCSI IDs if you use either a different channel on the SCSI controller or a separate SCSI controller.

DRaine3 · Answer

Unfortunately this cable has nothing to do with the SCSI ID's or the SCSI controller. It is a separate small 10-wire ribbon cable, similar to those you would see inside computers with old AT motherboards running between the motherboard and a serial device connector on the back of a computer. The motherboard connector was a plug that would accept 10 pins (even though the serial connector only had 9 pins). This cable would likely have two such plugs, one at each end. Again, the 1x2 SCSI cage has a receptacle for this type of plug right next to the power connector - I just don't see another one anywhere on the system board that looks compatible for the other end of the cable. It could be that, though this cage (part number 7575D) will work in a 6400, it is not specifically designed to do so.

PowerEdge HDD/SCSI/RAID

Dell Poweredge SCSI backplane questions

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