Shutter Controller Addition

On the project I am working on at the moment. there are shutters on windows that open outwards. opening and shutting the shutters with the windows open is not a good idea !

There is a switch on the windows that indicates when they are closed (low voltage)

these are wired back to the alarm panel (cbus enabled)

I am going to add logic so the shutter can not operate when the windows is open for this job

what would have been great is a LOGIC tab on the shutter relay. I could have then added the group address from alarm panel and AND to the controlling group address.

is it hard to add logic tab like other relays ??

Wish list item for version 3.0 firmware !

Charles

 

Charles,

Do you have a PAC or a Touch Screen (with logic) on the project?

 

Pac

 

Good idea ?? Too hard to implement... ?? bad idea ?? still thinking about it...???

Would either make this any easier ??

 

Ahh the good old too hard basket, i have one of these too

 

Mine's bigger.

 

I guess it's a valid request. If it was me who was making the call on if it should be done, I would ask the following questions...

-Can this be done by using logic in another product (ie PAC, B&W MKII T/S or Colour T/S)?
-How often will such a feature be used?
-What other development(s) would be sacrificed to allow for this (there is only so much resource available)?
-Will this sell more units? or Will not having it cost sales?

 

Yes but it would be nice to do it with out needing them

When blinds/shutters motors should only be operated AND/OR when another condition exists.

A vegolla shuts when rain detected
Can not shut roller shutter with outside opening windows open
Can not shut blind with bifold doors open
Awning will retract if wind speed too high or raining.
Pool cover will not go over if wave sensor sences people in pool.
You open a sliding door from the out side and the inside sunblind goes up
If used as a Duct Damper controller. will operate if too may other dampers are closed and the heater is turned on to stop damage to heater

Other output units have this functionality..

Depends if you are working on the

http://www.cbusforums.com/forums/showpost.php?p=21002&postcount=2

as this is more important

Yes

No (but you then get the [PAC, B&W MKII T/S or Colour T/S] sale because you dont have the feature so better not to have feature !!

Charles

 

Thankyou Ashleigh this all makes complete sence now.

I was very impressed it worked on the old hardware...



>>(This is all dependant on getting the shutter operation time correct).

What is this time.

Is the default based on a particular motor

Charles

 

>>What is this time.

Is the default based on a particular motor<<


The time used is programmable for each installation. The time is the 'failsafe' time, which should allow just over the longest amount of time the motor needs to run to move the load over its full range in one direction.

If you have a load that takes longer in one direction than in the other, then this should be set to the longer of the two times.

As you can imagine, it is a compromise solution, but lacking position feedback (not likely to be available in most installs) and noting that travel time is affected by motor current, supply voltage, friction, viscosity of lubricant (curtains might open slowly on a cold morning and close quickly on a hot afternoon) and mass of load (especially for an installation involving a change in vertical position), it is the best we can do.

In most cases, where the driving motor is operating with a light load (and most of the above variations can be considered small), the travel time should remain within a few percent each time the load is moved, and the calculated potition will be also within a few percent.

If the position is REALLY important, you can always install a limit switch and use a bus coupler to stop the motion. I haven't quite thought this one out fully, but in having a play on the bench here, it appears that if the failsafe time is set to the next highest "standard" C-Bus ramp time, then issuing "ENDRAMP" by a bus coupler operating with the same group address as the shutter relay will achieve this when the shutter relay is operating in proportional mode.

 

How hard is it to write a couple of lines of logic in the PAC?

If 'GA' (shutter down trigger) is not OFF, and 'GA' (window open) is not ON, then set 'GA' (shutter down) to ON.

 

Why not just send the window switch to an analogue input unit, this will tell CBUS whether the window is closed or not. Get the analogue input unit logic to drive a relay channel, then connect the L through this to the shutter relay. So when the window is open the relay contact is open so there is no power at the shutter relay to drive the shutter motor down?

 

Cost there are 13 windows !

 

Could you use the LV signal from the window switch to drive a conventional two pole relay (12 Volt coil), with one leg wired in series with the shutter feed? ie: if the windows are open, feed to the shutters is also open; windows close, relay closes and circuit to shutters is closed. The other leg could feed back into the alarm panel as before.


_____/ __(RELAY)_________/ __(BLIND CONTROL RELAY)_____________BLIND


I suppose this would introduce a few additional problems - indication / status would be the main one...

Mark

 

@ashleigh, thanks for your clear explanation of this. that's a clearer explanation that i managed to get out of the application note.

one question: if one uses a slider to set the shutter position, is it important to ensure that the slider never sends the 'reserved' values of 98%, 99% and 2%? should i set the minimum to 3% and maximum to 97%?

and another question: is there a way to get the interpolated position of the shutter as it is travelling? (`get <identifier> level` returns the target level, not the actual level.) i'm assuming the answer is 'no', since:

thanks, simon

 

thanks @NickD for your great answer. it helped a lot.

after moving my blinds with a SHUTTER TOGGLE, c-gate shows the level of the group address as 249:

Code:

get //SHAC/254/56/142 level
300 //SHAC/254/56/142: level=249

level 249 translates to 98%, which means SHUTTER TOGGLE.

so how do i interrogate the shutter relay to obtain the actual level? (ie. how do i determine whether the blind is open, closed or in the middle, rather than just toggled)

is there some kind of sync that i can force c-gate to do?