M1 Lighting Control

[123]

This one is definitely for Spanky ... or someone who knows the details of how to programmatically control lighting on an M1.


The pc command lets you control a PLC Device (i.e. light). If you send a pc command, the M1 responds with a PS message.

The documentation for pc indicates the Extended Code can contain a number from 0-99 and represents a light's Brightness Level (for lights that understand PRESET_DIM). I assume that 0 = Off and 99 = On.

The documentation for PS indicates:
0 = OFF
1 = ON
2-99 = Dim Level
Therefore "1" indicates the light is On ... and so does 99 for all practical purposes.

Now here's the strange part, if you turn a light full-on (at the light switch itself), the PS command reports the light is at level "1" ... indicating it is full-on as per the documentation. However, if you use pc to transmit an Extended Code of "1" it will not turn on the light. In this case, my guess is that the "1" is being interpreted as a Brightness Level of 1% ... and that's not enough to illuminate a light bulb.

The results imply that the PS and pc commands, although related, do not interpret 0-99 the same way. PS uses "1" to indicate a light is on. pc uses "1" to set the brightness level to 1%.

Is this true or have I misinterpreted the results?

 

[Black Magic]

This is interesting. I can't answer your question, but I would like to tack on an observation. Using the Elk ZWave module and Elk Automation rules, I can’t reliably turn on a light with the brightness set to 100%. I have to use 99% for the light to turn on reliably using a rule. I wonder if this is related.

 

[123]

It might be related.

The pc command uses a two-digit field called Extended Code and, among other things, it is used to indicate a light's Brightness Level. The range is 00-99.

FWIW, in the driver I'm creating for Premise, I translate lighting requests for 100% brightness into a "99" Extended Code. So if you move a dimmer-slider to 99% or 100%, the driver sends the same brightness level ("99" = full on).