Thursday, September 8, 2011

Is Baumer the only company to have figured out PoE?

Power-over-Ethernet seems like an obvious idea: make GigE a single cable camera interface like FireWire or USB by sending the juice down the same wire as the image data. But a search for a PoE interface card has me rethinking my assumptions.

Let me take you through my thought process.

I noticed recently that AVT now offer a PoE version of their Manta cameras. I haven’t used the Manta but it seems an attractive price/performance offering, so I thought I’d take a look. Now the Manta comes in regular GigE and PoE flavors, and as I like the idea of not two but one cable, I decided to search for a suitable PC card.

To my surprise, the only company I could find with such a product was Adlink Technology. There may be others but Google doesn’t know about them and besides, it was the Adlink GIE62+ card that was recommended on the AVT website. This looks like a good product but I like to comparison shop, so I searched the websites of other PoE camera makers to see what they would recommend.

That was how I ended up at Baumer. Now this German company has a fine range of cameras, but what really got my attention was “the GigE Vision complete solution”.

The Baumer approach to GigE is to inject the power at some point between PC and camera. They’ll sell you a GigE Power Switch to do this, but in conjunction they’re pushing a “GigE Trigger Device”. This appears to be a micro plc that will sit in the electrical cabinet, counting encoder pulses and issuing trigger commands to camera and lights.

This strikes me as an eminently sensible approach. It means you run a single Ethernet cable from PC (presumably using an Intel Pro100 card,) to the controls cabinet, and from there you run a single cable, this time with electricity, to each camera. And as a bonus, you don’t need to program a plc to handle timing and triggering issues.

This is why I’m thinking that only Baumer have the right paradigm for PoE.


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