Keeping a 8ch contactor in sync

[fleetz]

Hi Guys,

Got a head scratcher!!

Have just bought a 8ch contactor for switching pool lights, pool water features etc http://www.bellson.com.au/fm/fm1.htm it from a local Australian company. They recently moded the FM only remote control to allow for hardwire control of each channel. Thought you beauty the M1 will control this bonza (Aussie for good!! )

Here is the rub! When I got the unit and checked it out and started connecting to the terminal to switch the channels the switching logic is for every contact closure it toggles between the on state and the off state. It doesn't have the ability to be configured for a relay on = ON and relay off = OFF. Momentary for on and momentary for off. The situation is if the unit gets out of sync then there in no way of correcting for it.

What the unit has got is a complimentary +5V tally for each channel, that is when you select a channel on a separate connector on the terminal strip there is a +5V tally open collector output. When the contactor channel is switched off it is pulled down to around .5V or close to ground.

What would be nice is to find a device that would take the M1 relay on all the time instuction and reading the +5V tally know you are switching that channel on.

Conversely it would be nice then to take the M1 relay off all the time instuction and reading the +0.5V tally and know that the contactor channel is off.

I can't think of a simple way to do it with just the M1. Anyone know of a device that might do what I am looking to achieve?

I get back to scrathing my head..... :lol:

Cheers,

Fleetz

 

[BraveSirRobbin]

Not sure I understand the entire situation here (I'm not fluent in Australian ), but are you using relays from the Elk to toggle the inputs or are you using voltage outputs from the Elk directly wired to this unit?

Reason I ask is if you are using relays, maybe you can possibly use a double pole and have the second pole deliver 12 volts to an input zone. Not eloquent, but it would sync up the state of the controller to the Elk.

 

[upstatemike]

I guess I would just connect the 5 volt status lines to 8 inputs on the Elk and use that to track that state of the contactors rather than trying to associate them with the status of an Elk relay. Use the input state in your rules for On and Off such as:

Whenever "some condition that triggers an Off" AND input 1 is On THEN relay 1 On for 1 second.

This way the Elk relay won't operate if the contactor (input 1) is already Off and things stay in sync.

 

[fleetz]

Thanks BSR and upstatemike,

Yes BSR I was laying in bed last night and thought I missed a salient point! What I am trying to achieve is keep each of the 8ch's of the contactor with my lighting on the M1.

I have fully implimented C-Bus system going into the new home, Ness here in Aus have a C-Bus interface for the M1 which I believe ELK will be releasing soon. Anyway I am able to assign a lighting channel on the M1 that in turn can be used to switch the desired contactor channel. The trick here is that when the lighting channel is on the desired contactor should be on. The contactor is "dumb" and the only way to know if a channel is on or off is by reading the LED status ie +5V or +0.5V.

If the power drops to the contactor unit all relays are returned to the off state. It would be nice to be able to recover from this situation too.

Just to expalin a little further again sorry this should have been in last nights post the contactor is going to located about 30metres from the house. There will be 2 X 9way control cables going to the contactor and the relay control which is located in the garage. The garage and M1 are about 20 metres away and have RS-485 comms for the relay. 1 of the 9 way cables will be for the relay control (1 common and 8 for channel) the other would be the return for the contactor status (1 wire Neg and 8 providing control voltage status) The 30 metre return 9 way run will see some slight voltage drops from the +5V and +0.5V but still would have a differential sufficient to useful.

Therefore I could install a input expander card in with where the relay unit is and where the 9 way status return cable will be. I have zero experience on how the zone inputs on an input expander enables you to read a voltage so some help with your experience would be great. Then write rule(s) that would track the M1 light control status.

Hope this paints a clearer picture than the one painted last night.

BSR you would want to be able to talk fluent Australian as you would need to have half your brain removed!! .......my head still hurts!!

Thanks for both you valuable input to date...hope you can further assist.

Regards,

Fleetz

 

[paulw11]

Therefore I could install a input expander card in with where the relay unit is and where the 9 way status return cable will be. I have zero experience on how the zone inputs on an input expander enables you to read a voltage so some help with your experience would be great. Then write rule(s) that would track the M1 light control status.

Hi Fleetz,

I would connect relays like the Ness 101-283 to the status line and then use the relay contacts to switch the M1 input to ground. That way you have isolated the controller from the M1. You could also use the Ness 101-284 if you are worried about the voltage/current available from your contactor.

Paul

 

[FrankMc]

Hi Fleetz

I personally would use opto isolators between the contactor controller and your M1 Input expander....Does Ness sell such a board ???

Frank

 

[paulw11]

Hi Fleetz

I personally would use opto isolators between the contactor controller and your M1 Input expander....Does Ness sell such a board ???

Frank

Ness makes the "Australian" M1 for/with Elk. The part numbers I referenced are basically the Elk-912 and Elk-924.

Ness don't sell opto-isolators but they are available from electronics supply places. The problem with optos will be that you either have to mount them on a board and wire them up or use more expensive solid-state relays. The Ness/Elk relays are cheap and are easy to wire.

Is there are particular reason you would use an opto isolator? I wouldn't be surprised if the contactor already had opto-isolator in it to provide these signals.

Paul

 

[FrankMc]

Hi Paul


>Is there are particular reason you would use an opto isolator?

They draw minimum power from the circuit they are monitoring ........

>I wouldn't be surprised if the >contactor already had opto-isolator in it to provide these signals.

Fleetz mentioned

>there is a +5V tally open collector output. When the contactor channel is switched off it is pulled >down to around .5V or close to ground.

Which means it must have a pull up resistor connected to the open collector output .....depending on the value of the resistor there may or may not be enough current to drive a relay ...???

If it were true open collector output then he could connect the open collector outputs directly to M1 inputs and ensure the 0v (gnd) of both the M1 and the 8 channel contactor are joined together...

Frank

 

[paulw11]

Fleetz mentioned

>there is a +5V tally open collector output. When the contactor channel is switched off it is pulled >down to around .5V or close to ground.

Which means it must have a pull up resistor connected to the open collector output .....depending on the value of the resistor there may or may not be enough current to drive a relay ...???

Frank

Fair enough. The Elk-924 relay would probably still be easier. These relays have a local power input and a transistor to trigger the relay.

Paul