Power fail on shutter relays

What happens on return of supply after a power fail with the shutter relays, I would assume that they go to the power fail recovery state dictated in a switch or C-Touch unit.

Now if I have a backup supply, dc to ac gear, for when the ?the third world power company - Countryenergy? supply drops out ? are the shutters going to stay in their last state or am I going to have to get control of their ?group address? and return then to a known state.


dave

 

The Shutter Relay units always remember their last known state.

At power-up, the network MMIs ensure that the state in any input units, such as key units or C-Touches, gets cleaned up to match the state of the Shutter Relay, regardless of the power-up settings in the input unit.

 

Does this work across networks?

I have 31 shutter controllers on their own network and bridged to the main network (I have 99 units on main network so shutters had to be offloaded).

 

The clean-up of states/indicators does not work across networks. This is because it uses the MMI mechanism and these are not transmitted by network bridges.

 

Newman
That's great as I have 75 shutter relays that I need to put on a second network
as already have 100 units on local network.
But a they (shutters) should stay in the condition they were last in and the power fail recovery on a Pac/C-touch should set them to the last state they know about ???

dave

 

Dave

The PAC/C-Touch won't change the state of the Shutter Relays at power-up. If your PAC/C-Touch is programmed to remember the last level at power-up then everything will be fine. If your PAC/C-Touch is programmed to power up at a specific level then all that will happen is that the indicator on the C-Touch may be out of sync until the first time the user presses the button.

 

Newman.
This site has lots of power failures and they want to put in backup supply to drive some of the C-bus loads. What I do not want to happen is say all the shutters open on switch over to the backup supply. The C-touch takes weeks to load up so it not good at getting control in short time - power could be back before it gets going.
But if shutters stay in the last position its only the status of buttons on C-touch that could be out, what about status on DLT.

So its only when a new message put on sytem that status will come correct ??



dave

 

Status on DLT or any other key unit in C-Bus is derived from the output unit status. Even if the DLT powers up with a conflicting status due to a power recovery option to recover to a fixed level ... within a few seconds, the DLT status will change to agree with that of the output.

Not 100% sure about C-Touch, but I believe that it also derives status from output units where possible (C-Touch groups are frequently not associated with output unit groups).

 

If the units are on the same network, everything will automatically sync up and the Shutter Relay will not run.

At power-up, the Shutter Relays always stay in the last position. They do not run. If the power-up state of some other input unit, like a DLT, C-Touch, PAC, etc is not programmed to remember the last state, then you have a 50/50 chance that the state on that input will not match the shutter relay. Everything will be in sync after the first operation of that input.