M1G Analog Inputs

[Mike_]

Hi Monk,

I took some measurements.

The 'Spot ON' is powered by a 5v regulator from the 12v bus.

With the zone is isolated from ELK and the sensor not tripped, I measure +5v (relative to bus -). When the sensor detects motion, this goes low to 0v.

With the zone connected to the ELK and the sensor not tripped, I measure 13.1V between the zone and bus -.
With the zone connected and detecting motion, I measure 0v between the zone and the bus -.

I am not using a EOLR.

In ELKRP, the zone is type two, normally open.
ELKRP reports the zone as open 13.1V.
It's connected to a zone expander.

 

[Monk]

Thanks Mike_,
In essence, you are supplying a low in order to activate the zone, which makes sense.

Hi Monk,

I took some measurements.

The 'Spot ON' is powered by a 5v regulator from the 12v bus.

With the zone is isolated from ELK and the sensor not tripped, I measure +5v (relative to bus -). When the sensor detects motion, this goes low to 0v.

With the zone connected to the ELK and the sensor not tripped, I measure 13.1V between the zone and bus -.
With the zone connected and detecting motion, I measure 0v between the zone and the bus -.

I am not using a EOLR.

In ELKRP, the zone is type two, normally open.
ELKRP reports the zone as open 13.1V.
It's connected to a zone expander.

 

[Lagerhead]

With a TS7805 voltage regulator you can attach all sorts of stuff to an ELK.

The 'Spot ON' is powered by a 5v regulator from the 12v bus.

In essence, you are supplying a low in order to activate the zone, which makes sense.

So, the TS7805 is really not an interfacing solution at all.

Elk could address the matter of analog measurement on M1 zones in a few ways --
1. A "white paper" from Elk Engineering -- "How to Measure Analog Voltage and Current With the M1."
2. A new zone expander, M1XGPIN, which would omit the pull-up resistors on the zones, or bypass them selectively with jumpers or DIP switches, or (best) have them configurable either way from RP2.
3. A stand-alone interface device that accepts a variable voltage or current input and links that input proportionally to an analog-defined zone. This could provide input isolation and, as a bonus, could improve the resolution of the zone in cases where the valid input range can be constrained.

 

[Lagerhead]

Can someone please explain how I can 'input' a 5v analog signal into a zone?

TO PETER - VE9PTR

I would use an optoisolator. Though you describe this as an analog signal, your purpose seems to be just to detect on vs. off. An optoisolator is ideal in this situation because (1) you already very likely have the LED drive current available from your garage door monitor and (2) the optoisolator will provide a nice clean transistor switch closure to the M1 zone. In this case you do not configure it as an analog zone but as an ordinary closed-when-violated zone.

 

[Spanky]

The voltage range on the analog inputs on the M1 range form 0 to 14 VDC. 14VDC = an analog value of about 255.

5 volts will read around 100 more or less.

You will write Rules with a timer triggering the Rule to fire and do a comparison of the analog levels.

 

[Lagerhead]

[snip]
The problem is the Elk is made for open collector inputs and they have a 'pull-up' resistor that could interfere with an analog input that does not have the sufficient 'drive' to overcome this resistance.

You could simply try it, set the input as an analog setting, then see the value in the 'panel' on the RP software setting. Be aware though that if it is hooked into anything 'sensitive' on your end, it may possibly damage the hardware (it probably will not, but have to put this disclaimer out there since I don't know all the details).
[snip]

Spanky seems not to have acknowledged this significant point. Which was the crux of the discussion.

 

[signal15]

Signal15, you could have used a 555 or a cheap micro to send the signal to the Elk. The TI MSP430s are cheap. Simple set a timer once you receive a voltage and set the timer longer than the cycle time of the on/off period and check for a high/low or low/high and reset the timer. If the timer goes off drop the signal to 0. Does that make sense?

Yeah, I have a whole baggie of these things, but just haven't gotten around to building something.

I had the blinking light charging up a transistor, and then using a resistor to draw the discharge out over a longer period of time through an opto isolator, but there wasn't enough charge there to keep it open for the whole time the LED was off.

 

[murphy]

Can someone please explain how I can 'input' a 5v analog signal into a zone? I have a 5v signal (from an LED on a garage door monitor) that I would like to use, but rather than put a relay in, I think I can use the analog voltage value as my trigger. I see in the rules how they are applied, but I cannot find in any manuals or online how to actually connect a voltage input. Simply applying it accross the Com/Zone terminals seems to be what's implied.


Thanks in advance!
Pete

Hi Pete, I hope I did not misunderstand you. But IMHO that is very easy:

Let's say you are using input 15 to monitor the 5 V Voltage.
Just connect the Voltage (maybe over a safety resistor of some k Ohm) with the entrance of Input 15. Obey the polarity.
The rest is adjusted by the software.
You need the ELK-RP Programm to say/define the Input 15 as "analog".
Roll down the definition-menue to point/kind 34! And then you can use this Input in any rule. For example:

Whenever every 10 seconds
if input 15 is 5.0 Volt
Then task 22 (say garage open piiiep) ... or so.

But I would rather use a relay and a contact which is telling the ELK the garage-LED-condition:
1. - There is a 8 bit A/D-converter involved. What happens if there are not 5.0 but 4.8 or 5.2 Volts ??
2. - A contact is also programmable to a changing condition, just opening or just closing. And that's maybe better
3. - I haven't testet this in reality. But maybe the involving A/D-converter is slowing down the system too.

Good Luck.

 

[VE9PTR]

Hi Pete, I hope I did not misunderstand you. But IMHO that is very easy:

Let's say you are using input 15 to monitor the 5 V Voltage.
Just connect the Voltage (maybe over a safety resistor of some k Ohm) with the entrance of Input 15. Obey the polarity.
The rest is adjusted by the software.
You need the ELK-RP Programm to say/define the Input 15 as "analog".
Roll down the definition-menue to point/kind 34! And then you can use this Input in any rule. For example:

Whenever every 10 seconds
if input 15 is 5.0 Volt
Then task 22 (say garage open piiiep) ... or so.

But I would rather use a relay and a contact which is telling the ELK the garage-LED-condition:
1. - There is a 8 bit A/D-converter involved. What happens if there are not 5.0 but 4.8 or 5.2 Volts ??
2. - A contact is also programmable to a changing condition, just opening or just closing. And that's maybe better
3. - I haven't testet this in reality. But maybe the involving A/D-converter is slowing down the system too.

Good Luck.

Thanks for all of the great info! I have ordered 2 sm relays and will give this a try when they arrive, if not I'll try another of the suggested routes. I'm trying to avoid simply inputing the 5v for fear that it may cause problems with either the m1 or the garage door monitor itself.

Murphy - your comments above triggered another question for me (sightly off topic) but what's the reason for a 'WHENEVER EVERY X SECONDS' statement vs a simple 'WHENEVER' (other than the obvious time delay)? I guess I'm not sure why in this case you wouldn't want contiuous monitoring, as I have only used WHENEVER's thus far in my short month of elk ownership!

Thanks again to everyone,
Pete

 

[Lagerhead]

...what's the reason for a 'WHENEVER EVERY X SECONDS' statement vs a simple 'WHENEVER' (other than the obvious time delay)? I guess I'm not sure why in this case you wouldn't want contiuous monitoring...

Simply, it's not available for analog-defined zones. Analog changes do not trigger WHENEVER. You have to check the values periodically.

...I have ordered 2 sm relays and will give this a try when they arrive...

Remember to put a reverse diode in parallel with the relay coil, to absorb the currents when the coil opens. This is another advantage of using an optoisolator instead of a relay -- no coil, no back currents. (Also, no moving parts.)

 

[Spanky]

The M1 Rules Engine uses events that are happening to make the engine run through its processes. Ie. a door is opened and the engine evaluates what to do when that door opens.

In the analog world of sensing inputs, there is not a WHENEVER analog voltage trip point built into the Rules engine to run the process. Therefore a timer is the WHENEVER event that starts the engine running the Rules process and the use of AND statements determine the levels of analog voltage that is being evaluated in the Rule.