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Sensor Switch CM PDT 9 Wiring and Programming Question


New Member
Happy holidays everyone.
I ordered a few Sensor Switch CM PST 9 R (with relay) Occupancy Sensor to connect to an Elk M1.  I have bench wired one up and it works as expected using the relay going into a normal zone.  There is an audible click when the relay changes state.
I thought that I had to use the relay version, because the base model CM PDT 9 only has RED (12-24VAC/VDC +), Black (Common), and White (Occupancy State High VDC for occupied).
I was afraid that connecting the White - High VDC to the + zone input would introduce voltage into the system or cause a problem.  Especially, since the power would be coming from an Aux power supply and I image it could be slightly different (within range) from the M1 voltage.  I found a previous post where MONK stated he uses the base occupancy sensor.
First Question:
Is it OK to wire a standard CM PDT 9 Occupancy sensor (without built in relay) in this way:
RED = +12VDC from Aux power supply (Altronix AL600ulx)
Black = -12VDC from Aux Power supply AND NEG zone input (Note: Negative from Aux power supply bonded to M1 Negative)
White = + Zone input
Second Question:
Occupancy Sensors should be programmed in ELKRP as Definition: Non-Alarm and Type: Normally Closed, correct?
This is working as expected with the Relay version I am testing.
Third Question:
For those of you familiar with the CM PDT, it has a photo cell that can prevent the occupancy trigger when there is enough ambient light.  There are also 2 wires coming out of the sensor: Blue: Direct output to powerpack for providing photocell and/or secondary dim time out.  Output also held high during secondary time out. Violet w/ White Stripe: Connect to 0-10VDC control wire from 0-10VDC dimmable Ballast.
Does the photocell control the triggering of the WHITE standard output, or do you have to utilize the Blue or Violet wires for the photocell?
Fourth Question:
Are EOL resistors polarized?  Does a particular side of the resistor need to be connected to the negative side of the loop?
I am not planning on EOL for the occupancy sensors, but needed to know for the other zone sensors.
Fifth Question:
Slightly off topic, but what types of sensors are best for controlling lights in a straight stairway?  Would you ceiling mount an occupancy sensor midway up the stairway parallel with the stairs?  Stairs are 3'8" wide and 18' long.  CM PDT 9 manual shows that mounted 8' off the ground would detect approx 10' in either direction.
Sixth Question:
The ElkRP manual nicely goes through the basic setup steps for the software, but lacks greatly in defining what many options actually do.  One example are the Zone definitions, there are several that have very similar descriptions.  I would like to understand better about what the differences are.  Does anyone know of any other resources for the Elk RP software to understand the immense amount of options?
I would lie to say thanks to all the dedicated Cocooners on here.  This forum and the Elk online videos are why I chose the M1 system.  Tons of DIY'er support.  I have been reading and researching for months.  I hope to be able to give back to this forum as my knowledge about this system grows.  I have my M1 set up on a bench test. We just broke ground on the house, so I have a few more months until I begin to pre-wire, then install my system.


Active Member
As for part of the First and Second Questions, see Spanky's post (#9) in this thread about how to directly connect the M1 to a Sensor Switch.  I don't have an Altronix (yet) so I can't pass on that aspect of it, but the post shows how to wire a CM PDT 9 directly using the M1's power. 


New Member
TurboSam, Thank you.  I know it sounds silly, but I am still learning to use the search function...  I searched for 2+ days for that answer, but I always broke sensorswitch into 2 words.  That post will not show at all with sensorswitch as two words.  I even just tested searching for "sensor switch cm-9-r".


Senior Member
The Cocoontech search function isn't the best.
A better way to search is to let Google do it.  Just type in your search words on Google and add site:coocontech.com to the end, you'll have better luck.