All of
 help / color / mirror / Atom feed
From: Patrick Williams <>
To: Mike Jones <>
Subject: Re: PMC
Date: Fri, 23 Apr 2021 12:19:21 -0500	[thread overview]
Message-ID: <YIMBmRyyjcchQFhA@heinlein> (raw)
In-Reply-To: <>

[-- Attachment #1: Type: text/plain, Size: 1329 bytes --]

Hi Mike,

On Fri, Apr 23, 2021 at 08:49:05AM -0600, Mike Jones wrote:
> Patrick,
> We are using spec: Open Rack V3 48V BBU.

Got it.

I think you'll want to look here:

> In the case of a PMC, since I don’t know the OCP architecture well, is there a PMC device in the rack that would manage a BBU, or do devices that plug into their rack each have a PMC?
> Looking at the above spec, the functions of the MCU are quite limited, so I assume there is a PMC device that is managing these other elements like a BBU. 

If you look at the Power Shelf design you'll see mention of a PMC/PMI
connector.  This is a slot for which two different designs can fit into:
PMC or PMI (and I don't recall exactly what the "I" stands for).

With PMC, the intended design was this was a full BMC-class device with
a network interface.  This would run OpenBMC.

With PMI, there is a MCU in place of the BMC and the PMI is connected to
the top-of-rack switch using a modbus / RS-485 over RJ-45 implementation
like was available in ORv2.  I think the PMI would speak the same exact
protocol as the similar device in ORv2.

You might find details on this modbus protocol in the above link, but
there is a lot to dig through...

Patrick Williams

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  reply	other threads:[~2021-04-23 17:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-16 19:40 PMC Mike
2021-04-23 13:28 ` PMC Patrick Williams
2021-04-23 13:39   ` PMC Mike
2021-04-23 14:49     ` PMC Mike Jones
2021-04-23 17:19       ` Patrick Williams [this message]
2021-04-23 17:30         ` PMC Mike Jones
2021-04-30 14:26           ` PMC Patrick Williams

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YIMBmRyyjcchQFhA@heinlein \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.