Logic redundancy

Hi guys,
I have a site with substantial amounts of logic within a CTC. Basically the way it works, the system would be almost useless if the logic fell over.

• What would be the best way to ensure there is a 'redundant' logic system?
• Would it be a PAC or second CTC?
• Is there any function(s) within the logic to say if logic is running on 'primary' system, do not process on 'secondary' sysetm unless 'primary' not available?
• Is this what the 'master' unit selection is in the setup?

Cheers

Grant

 

The easiest way is to have a second, identical, CTC. Have one set to Master and one set to be the slave.

Using logic, you can see if a unit is the Master unit:

Code:

if GetBoolIBSystemIO("Master Unit") then

and you can set a unit to be a Master unit:

Code:

SetBoolIBSystemIO("Master Unit", true);

You could have the Master unit send a regular "heart beat" message onto C-Bus, such as toggling a group address every minute. The slave unit can then monitor this and if it doesn't see the heart beat for a few minutes, then change itself to be the Master.

Do do it "properly" is a bit more complex, but this should generally be good enough.

 

so are you saying the 'slave' does not process logic?

or the "if master" condition needs to be used so that "if master' = false disable all modules...

or something like that.

Cheers

Grant

 

The slave does process logic, it just doesn't send anything onto C-Bus from Schedules or Logic.

 

so it processes everything but its *outputs* are inhibited until it is the 'master'?

 

Correct.