Conference netcad::hub_mgnt

    Jon,
    
      The H7894-MA power supply is rated for 163 watts of output power as
    opposed to the 140 watt rating of the H7890-MA. This slightly higher
    power rating will allow the use of 7 bridge modules as oppsed to 6 with
    the H7890 supplies. In addition the H7894 has a power factor correction
    (PFC) AC front end which meets the upcoming requirements of IEC555-2.
    At this point in time it looks like PFC supplies will be required in
    1996 (not sure which month) for any product which draws in excess of 70
    watts from the AC line. Other features of the H7894 are as follows:
    
    50 degree C operation as opposed to 40C with the H7890
    Fan_Fail signal in the power supply which tells the hub when a ps fan
    has failed.
    Lower input operating current due to the power factor corrected front
    end.
    
      Let me know if you have any further questions about the H7894-MA or
    the Powerswitch product (H7661-AA).
    
    Bob

    Bob,
    
    For the H7894-MA, what's the Amp rating at +5V and +15V?  Have they
    been changed at all?
    
    Thanks,
    
    Clinton

	The maximum current remains the same...

	5v @ 26a
	15v @ 4a

    Just to make it clear, the new H7894 power supply is a replacement for
    the H7890 power supply and is shipping in hubs now. It is also true that 
    the new power supply is rated at 163 watts. However, the Hub manager code
    releases up to this date including V4.0.2, do not allocate anymore than 
    140 watts per supply for either the H7890 or the H7894.
    
    Engineering is currently investigating allocating more power.
    
    
    

    Nat,
    	Has it really started shipping ?
    
    Last week there were no HUB900 psu's of any description shipping
    
    regs
    ross
    

>    Just to make it clear, the new H7894 power supply is a replacement for
>    the H7890 power supply and is shipping in hubs now.

  I heard in Larry Walker's caf talk this morning that there is some kind of
problem with the new (third-party, mfd in Austria) power supply that had
caused production to be stopped for a while, but was recently fixed. Is the
H7894 the model in which this problem occurred?

>   It is also true that 
>   the new power supply is rated at 163 watts. However, the Hub manager code
>   releases up to this date including V4.0.2, do not allocate anymore than 
>   140 watts per supply for either the H7890 or the H7894.
    
>   Engineering is currently investigating allocating more power.
    
  How will the future Hub manager allocate more power? Will it sense what model
of power supply is in use and allocate the power accordingly? 

    Yes Bob, the H7894 is the product that was recently fixed.
    
    On the other question of allocation, it's my understanding that
    the current Hub Manager firmware will not discriminate between
    the older model H7890 and the newer replacement model H7894.
    I can't speak for later revs of MAM firmware as to whether the
    allocation algorythm will be changed or not, only that the 
    current shipping rev won't allocate any additional power even
    though the H7894 has more available. I think there was an earlier
    reply that stated essentially the same thing.
    
    Bob

Yes, in a future release, it will read a power supply control/status 
register to determine which model power supply is installed and allocate 
power accordingly.

							-Shawn

    >Yes, in a future release, it will read a power supply control/status
    >register to determine which model power supply is installed and
    >allocate power accordingly.
    
    Any idea of timescales?  Even roughly?
    
    Another thing: with the new 163W PSU, one added advantage was that the
    increased Wattage allowed the max number of DECswitches per hub to rise
    from 6 to 7.  If the hub is not currently able to allocate more than 140W, 
    even with the 163W PSU, does that mean that we can still only have 6
    for now?
    
    
    Clinton

Soon, very soon.  N weeks, not NN weeks.
If you need a better hint, contact the product manager.

The consolidated release today containing DMHUB V4.0.4 is
*not* the release containing support for 163 watt power
supplies.  V4.0.4 contains only a diagnostic fix to V4.0.2.

    	I have a customer that is installing a H7894-MA. this is the second 
    power supply in the hub. The LCD on the hub indicates N+1 power,
    however the DC OK led on the second supply is not lit. I can not find 
    anything indicating what this LED monitors. Any information would be 
    appreciated.
    
    Ray