Question about check configure status for CEM+

Dear All,

I've loaded a configure files into two seprate CEM+ which intend to use for Rack 1 and Rack 2.

I put CEM+ one by one (Rack 1 then Rack 2) into the ETC customize made OVEN purpose check configuration status.

When I put second CEM+ into oven. the screen show up the information that actually is first CEM+.

I have to log into as power user go to rack /set group&rack/group number 1/rack number 1 (note need manually swap to 2)

after (systen updating setting please wait) system reboots then this CEM+ screen show it use for rack 2

If I put CEM+ which for Rack 2 first. the problem still same the only different is I had swap from 2 to 1

I am wondering this happen would be a bug or just by system default.

Please let me know if anyone knows about!

 

Cheers

 

Yang

 

 

 

 



[edited by: asyzg at 11:06 AM (GMT -6) on Mon, Nov 17 2008]
Parents
  • Yang,

    It turns out that this is a feature by design.  There is a chip in the backplane that contains a copy of some of the basic configuration information and acts accordingly when a CEM+ is cahnged out.

    For a 1 rack system, the backplane chip contains a copy of the entire configuration and will ask you if you want to use it when swapping CEM+s.

    For a multi-rack system (such as you have configured), the backplane chip keeps a copy of the Group #, Rack #, and config checksum.  If you place the rack 2 CEM+ into the oven when it was configured for Rack 1, it will automatically change the #2 CEM+ to Rack 1.

    To defeat this feature, simply remove the backplane chip.  It is the 8-pin DIP serial EEROM that you see in the front and middle of the backplane.

    Let me know if that helps.

    David

Reply
  • Yang,

    It turns out that this is a feature by design.  There is a chip in the backplane that contains a copy of some of the basic configuration information and acts accordingly when a CEM+ is cahnged out.

    For a 1 rack system, the backplane chip contains a copy of the entire configuration and will ask you if you want to use it when swapping CEM+s.

    For a multi-rack system (such as you have configured), the backplane chip keeps a copy of the Group #, Rack #, and config checksum.  If you place the rack 2 CEM+ into the oven when it was configured for Rack 1, it will automatically change the #2 CEM+ to Rack 1.

    To defeat this feature, simply remove the backplane chip.  It is the 8-pin DIP serial EEROM that you see in the front and middle of the backplane.

    Let me know if that helps.

    David

Children
  • This feature is necessary for proper performance of a multi-rack system.

    Without some way to determine the group, rack number and IP addressing of a given rack, it would be impossible to swap CEM+ out without reconfiguring them every time.

    If the IC is removed or destroyed, you may see "Backplane Com Error" or "Backplane Fail" errors.

  • Thank to everone for your quick response .

    David,  thank you let me this is the case. It has worked without any issues.

    Richard, as you mentioned "without some way to determine group, rack number and IP addressing of a given rack .........."

    Can you advise me,  How can I do it ?

    my own way as follow:

    First CEM+  (Group 1/Rack 1), IP 10.101.101.101; Sencond CEM+ (Group 1/Rack 2), IP 10.101.101.102;  all through the backplane.

    After Use CEM+ web broswer load configure into it

     

    Many thanks and best regards

     

    Yang

     



    [edited by: asyzg at 7:06 AM (GMT -6) on Tue, Nov 18 2008]
  • I think you've misunderstood.

    In any real system, each physical rack must know who it is. If a rack didn't know it was (eg) Rack 2, then putting the CEM+ from Rack 1 into that rack would instantly make that rack behave as if it was Rack 1.

    A Test Oven also contains a backplane with the configuration IC, and can be configured so that the oven itself knows that it is Rack 1 or whatever.

    CEM+ Processors do not know which rack they are - they each contain the configuration for the entire Group, and will load whichever section of that configuration they are requested to do so when they boot.

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