What our dear boy LT means to say is: "Gee, that's a pretty fundamental question. Do you have any user manuals to read on the subject ? 'Cause we don't feel like typing them in".
A connector came with the scanner module, right ? Those red and black labeled pins are where your +24 VDC and COM power connections go.
If you have not read any of the fundamental DeviceNet books like DN-6.7.2 or watched the slideshow tutorial that comes with RSNetworx for DeviceNet, please do so.
I spend about 50% of my time teaching, troubleshooting, and tuning DeviceNet systems. But I'm not going to hold your hand about where to connect the everloving power wires.