I don’t have the exact part number or timing yet … the DOIAP hardware is being respun due to some of its components being end-of-life’d by suppliers and the new hardware will split into 2 models. The PoE adds nearly 8% to the cost-to-manufacture a DOIAP (mainly the 2nd isolation transformer & supporting circuitry) and few people use it. Remember, the DOIAP already includes extra cost for the isolated DC-to-DC on the 10-30vdc power input, so PoE is literally a 2nd “isolated DC-to-DC” circuit within the same box.
So Fall 2006 the DOIAP will follow the other Digi products and have PoE moved from the standard model into a special model. As part of this split, the PoE will also be updated to full PoE with both mid-span and end-span support.
So users expecting to use PoE will need to adjust their buying (or stock up on the current model ).
I’ll try to get more details for you’ll. The exact timing is being driven by the balancing act of trying to consume as much of the obsolete part-stock as possible.
Actually, a question - do people who use PoE also use the normal 10-30vdc at times? Current plan would be to have the DOIAP with PoE also retain the 10-30vdc isolating power input … but I was just thinking if people desiring PoE didn’t need the 10-30vdc ever it could cut considerable duplicate cost to just make a PoE unit that only used PoE.
> Actually, a question - do people who use PoE also use
> the normal 10-30vdc at times? Current plan would be
Yes. But never both at the same time.
> to have the DOIAP with PoE also retain the 10-30vdc
> isolating power input … but I was just thinking if
> people desiring PoE didn’t need the 10-30vdc ever it
> could cut considerable duplicate cost to just make a
> PoE unit that only used PoE.
We would never require that the PoE power supply be isolated from the existing DC input. Not sure if that would cut costs or not. (Just thinking y’all might be able to get by with one shared isolating transformer, rather than two.)
We don’t use many–maybe 5-10/year, so maybe our opinions don’t count for much. (We’re also the guys that like to pull the board out of the case and pot it.)
We’re already paying a pretty hefty premium for the automation protocol support (over a plain Digi One), so a slight premium for solid PoE support wouldn’t be a problem.
We’d rather pay more and get both PoE and normal DC input as opposed to holding the current price for a product with PoE and no external DC input. (Having to stock two products instead of one is a hassle.)
Ok, that confirms my gut feel that trying to supply a PoE-only unit would be more pain than gain.
We couldn’t use a single transformer. The raw PoE seen is ground referenced to the Cisco or whoever is supplying the power. I’m pretty sure the 802.3af rules demand the “poweree” fully isolate/float the power from the “powerer” to prevent ground loops. DOIAP shorting the 10-30vdc supply to the PoE would short the central 24vdc ground to the Cisco ground if one accidently connected both at once.
> Ok, that confirms my gut feel that trying to supply a
> PoE-only unit would be more pain than gain.
Well, for us at least.
> supplying the power. I’m pretty sure the 802.3af
> rules demand the “poweree” fully isolate/float the
> power from the “powerer” to prevent ground loops.
> DOIAP shorting the 10-30vdc supply to the PoE would
> short the central 24vdc ground to the Cisco ground if
> one accidently connected both at once.
Yeah, might be a problem there.
Hey, I think it would be really nice to have a power output. Then we could power the DOIAP from PoE and in turn steal (limited) power from the DOIAP to run our hardware.
As of today, we should have a NEW version of the Digi One IAP hardware out in Jan 2007 (or Feb 2007). This is mainly to design out some end-of-life’d components, but does include some general fixes or improvements.
Changes:
For better or worse, the NEW hardware will remove the PoE from the standard DOIAP and a 2nd product likely called Digi One IAP PlusPower will have the newer PoE design supporting either end or mid-span. I don’t know the exact new product names, prices, or model numbers.
The input DC-to-DC power isolator has been changed to have no inrush current, so you should be able to use the small 7watt 24vdc DIN-rail supplies from someone like Omron or Idec. The older design had enough inrush to normally cause these small supplies to treat as a short-circuit.
The serial lines will inherit true transient surge diodes with defined IEC-waveform specs. The old hardware had better over-voltage protection than standard Digi products but the exact spec was fuzzy.
The GoodLink LED will become “normal” - Green means GoodLink and dark means none. The old design (for legacy reasons) was dark means good and RED mean no-link.
The way the 2 ports verse 1 port will change slightly - the old hardware used a dual 232/485 chip which turned out to be too expensive and didn’t support its own published spec! For example, applying a +12.1v signal to an RS-232 input caused it to latch up and start heating. That is not good; one wonders why the chip maker didn’t handle this. So the new design uses better (and more standard) RS-232 and 485 chips.
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