topic Re: Simple Dual Redundancy Component in Components

Simple Dual Redundancy Component

Christian_L — Fri, 15 Aug 2008 14:55:35 GMT

Please post your comments, questions, and feedback on the Simple Dual Redundancy Component here.

Re: Simple Dual Redundancy Component

rtkrvj — Thu, 16 Apr 2009 09:45:08 GMT

Hi!

After reading the article, it seems that there is SDR device in between Active and hot standby Controller.

Since we are implementing dual redundancy so that we can recover from backup.

But what if the SDR fails and thus fails to provide dual redundancy to controllers.

Otherwise Article is good.

I am expecting a reply for this one:)

/ rtkrvj

Re: Simple Dual Redundancy Component

DavidEngr — Fri, 17 Apr 2009 15:39:25 GMT

Hi rtkrv,

The SDR is a software-based implementation of redundancy and there is no extra device between the controllers (apart from the serial cable used for communication).

Re: Simple Dual Redundancy Component

rtkrvj — Sat, 18 Apr 2009 07:31:05 GMT

Hi,

Glad to see the reply:)
I have one more question regarding it, i.e.
In normal state, input to both the control units will be there and only failure of a primary control unit, secondary control unit starts sending the output.
Correct me if I am wrong.

Now my question is that do we need to have an I/O processor unit to send input to both control units at every instant?
eg:
Sensors>>IO processor Unit>>Primary Control Unit>> output
>>Secondary Control Unit
If Primary Control Unit fails, then
Sensors>>IO processor Unit>>Primary Control Unit
>>Secondary Control Unit>>output

Here, fault tolerance is done on Control Unit, but what if the IO processor unit fails?

Please revert in case of clarification.

Thanks, 🙂
/ rtkrvj

Message Edited by rtkrvj on 04-18-2009 02:29 AM

Message Edited by rtkrvj on 04-18-2009 02:30 AM

Message Edited by rtkrvj on 04-18-2009 02:31 AM