Emerson Exchange 365

Charms Baseplate Cables- Do I need both?

I have some supply chain issues preventing me from getting the cables that extend a Charm bus.  I have some cables I can steal from another currently installed project.

I have a redundant Charms config with two CIOCs, four bases directly connected to CIOCs and then four bases connected via extension cable, 8 total bases. 

Can I run with one cable? If it only effects redundancy, I can live with that until I get my new cables.

In diagnostics, it looks like have a good signal and just says "CHARM Bus Problem."  Faceplates for effect signals look happy.

The charms modules Analog or Discrete downstream from cable are flashing red at a rate of 1.5-2 secs with one of the cables removed on the existing install.

Thanks!

• baseplate
• Cables
• CHARMS

s_brwn

• 29 Jul 2022 5:50 PM
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4 Replies

• Bryce Elliott

  

  • 29 Jul 2022 7:07 PM

  If you can steal enough temporarily, I would try it with the redundant cables and see if the errors go away. That will verify that there isn't some other CHARM Bus Problem in addition to the one about which you already know.

  - Bryce H. Elliott, P.E.

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• s_brwn

  

  • 1 Aug 2022 12:10 PM

  In reply to Bryce Elliott:

  Sorry I didn't word my question correctly. I have two systems. One system has been in operation and is working fine. It has both cables.
  My new system has no cables due to supply chain issues.
  I planned on taking one cable from the functional system and use it on the new system.
  
  My question is if that will work and how if any does redundancy play in to it?
  
  Thanks

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• Andre Dicaire

  

  • 1 Aug 2022 3:44 PM

  In reply to s_brwn:

  The CHARMS beyond the missing cable will indicate their loss of communication on that bus. The value and status of channels will remain good, provide the remaining bus is healthy. The intermittent red LED indicates an existing issue with CHARM integrity.
  
  You can remove a cable without loss of control. This will set an integrity flag so you will want to restore this as quickly as possible.
  
  Each CHARM has two communication send/receive. If a CHARM loses the remaining comms, it would drop out without the secondary cables present and a loss of status and value. This highly unlikely, but the high availability of CHARMS is predicated on full comms redundancy.
  
  But they will run with a simplex bus.

  Andre Dicaire

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• s_brwn

  

  • 1 Aug 2022 5:00 PM

  In reply to Andre Dicaire:

  Thank you very much for the replies

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