Automate main gate - M1G

[Hermanus]

I am hoping one of the Elk gurus can help me out here. I want to set my house in an Arrive Mode as soon as someone opens the main gate. On the gate motor's PCB there is a LED connector that can be used to display the status (open or close) of the gate. What this gives is a 0 VDC when the gate is close and 4.5 VDC when the gate is open (to turn on LED). I was hoping to wire the LED connector to an Analog Zone (34) input on Elk M1G and write a rule to check every second or so what the value of the Analog input is and based on that put the house in Arrive Mode as soon as it goes above 3 VDC for example. When I test the value before inserting it in Zone 10 (the Analog Zone) it measures 4.3 VDC when gate is open and 0.1 VDC when gate is close. Which is correct, as soon as I connect the wires to Zone 10 (Analog Zone) the volts goes up to 9.6 VDC and stays there when gate is open or close, which can’t be used. - Thanks in advance.

 

[BraveSirRobbin]

All zones have a pull-up resistor which can't be removed unless you physically unsolder this surface mount component from the board (i.e. tricky). I'm guessing the input doesn't have enough current drive with this resistor in place.

Perhaps you could trigger a small dip relay with that LED and have its contacts trigger a zone. Or have that LED output trigger a transistor which would then trigger that relay.

 

[Photon]

Or skip the fancy stuff and use a reliable old magnetic contact switch on some moving part of the gate's hardware.

 

[znelbok]

I have successfully used a 5V solid state relay for integration of an LED "output" to create a signal into the M1. It was a Weidmuller part from memory. Worked quite well because it requires 12V to run and it gets that from the M1's zone output. I used them on my garage door.

If you want to measure external voltage, then you need to remove these pull up resistors. I would not call it tricky, more careful work. I used a small propane soldering iron that can be used as a heat gun to de-solder the resistors. I am using mine for measuring 4-20mA loops and some other voltages that represent temp on my sola HWS.

Mick

 

[Steve]

Or skip the fancy stuff and use a reliable old magnetic contact switch on some moving part of the gate's hardware.

Yea, was gonna say the same thing. Sometimes KISS is the best option. Also, a regular contact will work in a power failure where the LED monitoring won't (unless the gate is on UPS).

 

[gatchel]

I recommend the use of a relay of sorts if you are not going to use a gate contact. This will provide electrical isolation between the power supplies of the two devices.

 

[Spanky]

You need a transistor driver between the LED and the Zone input of the M1. Get any common NPN transistor, example: 2N2222, and some perf board from Radio Shack. Connect the emitter to negative back to the M1's negative. put a 4.7K ohm 1/4 watt resistor in series from the LED to the Base of the transistor. Connect the Collector of the transistor to the zone input.

When the voltage at the LED goes to 4.3 volts the input at the zone will be zero volts. When the voltage at the LED goes to 0 volts, the input voltage will be 12 V. Your Rules should then work as a non-alarm zone input.