Originally Posted by phildaant
Can Arris DCX3510 DVR's rear firewire, USB, and network be used for
I don't have one, so I can't speak firsthand.
But throughout Motorola/Arris history the USB and network ports have been non-functional as implemented by US cable systems using the hardware.
However the firewire port has ALWAYS been functional and active, intended for connection to an external DVHS VCR for offload/archiving of content from the DVR to DVHS tape. (With the correct drivers and OS on your PC, you could also offload/archive copy-freely content from DVR to PC.)
This DVHS VCR and firewire mechanism is usable for both copy-freely and copy-once content, so you can make a digitally 100% bit-perfect DVHS tape copy of any program you can watch/record on your DVR (thus excluding any pay-per-view or OnDemand, which is marked copy-never and cannot even be recorded on the DVR itself). Of course you cannot make a 2nd-generation DVHS tape copy of a DVHS tape copy of copy-once content (say if you had a second DVHS VCR which can connect to the first DVHS VCR by firewire) as the content is marked "copy-once". You can only have that first-generation DVHS tape copy made from DVR-to-VCR.
That said, ever since the initial early days of the DCX family of products the firewire recording mechanism has been "truly broken" or "iffy". Rumor had it that Motorola/Arris had finally fixed the firmware to get this working again to the essentially glitch-free 100% reliability of the earlier generation DCT* and DCH* boxes, both of which had TWO firewire ports on those units and also used a different manufacturer internal firewire chip on the motherboard.
With the introduction of the current generation DCX* equipment, they went to a single firewire port and a new manufacturer internal firewire chip, and that's what most likely conspired to "break" this previously usable firewire recording mechanism. Rumor has it that these early problems have finally been fixed with more recent firmware/software upgrades to the DCX* units, but I cannot confirm that since I don't use one.