How to provide UPS backup to PLM?

[developer]

Assuming I am using a PLM in a commercial environment and all the computers and devices are running on UPS because the topology is not large enough to warrant a genset, how does one keep power to a PLM?

 

I am thinking that (and I am not sure about any of this) Insteon depends on the cycle transition moment to tx-rx. If that is the case, then can it still perform on the ac line when there is a lack of power? Would there be a framing problem because multiple devices would have different artificially-created waveforms with differing 0 threshold transitions due to UPS independence? Is this why gensets feeding an entire building reportedly work and UPS doesn't?

 

If that is the case, then PLM's can indeed operate through a UPS (as I have been able to confirm), but the same UPS has to power all the devices that intend to communicate on the powerline to keep the waveform the same in the event of a utility failure. If true, then can a dual mode PLM still continue to use RF to manage devices not on the same UPS? I am thinking yes.

 

Can someone from Smarthome comment on this? Thanks.

[Brian H]

Most UPS units have power line conditioning. Including noise suppression. The suppressors will absorb all the Insteon signals going from the PLM to the power line. Even on AC Line Power.

 

Computer power supplies are wonderful signal absorbers or noise makers. So that maybe a factor.

 

Insteon signals are timed with the AC Zero Crossing of the AC waveform. If the UPS is not a Pure Sine Wave type it most likely not work. As the timing will be messed up.

 

Some modules with power line derived power supplies may also not like stepped sine waves from an UPS on battery.

 

Maybe by RF. Also the 2413S does not provide power to the ISY99i so an external wall supply is needed. It also has half the link database size of the original PLM.

[developer]

Ok then from what I am getting from this is that RF would most likely work as a fall-back, but the problem is that the PLM will derive its power from the AC line, which might be dead. So then, it makes sense to me that PLMs should have some sort of... shall we call it a "feature", whereby they can maintain network operation on the (in this case) ISY side and work in RF mode. I know the PLM feeds the ISY, but it would be my recommendation to have a version that can take operational power from an external source. Yes, non-rf version PLMs... well, when AC is down, you're dead in the water (even externally-powered, you're waiting for a transition bus that never comes), but with RF, you can keep going. Seems to me that not having the external supply which can plug into a UPS would partially defeat the purpose of having the RF capability when using it as a fall-back.

 

Thanks Brian. This is all just in search of a better understanding and perhaps food for thought for the powers that be...