Blog
The arithmetic, the standards and the failure modes behind every model we make.
Start with the power budget rather than the port count. A 24-port switch with a small supply is a different product from one with the same ports and twice the budget.
Power budget arithmeticCopper channels stop at 100 m. Extenders, fibre or a local supply each solve it differently, and only one of them keeps the camera on the switch's budget.
Running PoE past 100 mAdding cameras to a building with a plain switch does not always mean replacing the switch. Sometimes it means four injectors and a spare afternoon.
Injector or new switch
Power Design · 7 min read
Port count is the number people quote and the budget is the number that actually limits the site. A worked method for sizing PoE switches, with the arithmetic for af, at and bt classes.
Standards · 7 min read
The three PoE generations differ in voltage headroom, current, and how many pairs carry power. What that means when a camera refuses to boot or reboots at night.
Long Distance · 7 min read
Copper channels stop at 100 m. The three ways around it differ in cost, power loss and failure modes — and only one of them keeps the camera on the same PoE budget.
Selection · 7 min read
12 V domes, 5 V access units, 24 V PTZ heads — the splitter has to match the device, not the switch. How to read the label and avoid the two failure modes that get blamed on the camera.
Retrofit · 6 min read
Adding powered cameras to a building with a plain switch does not always mean replacing the switch. Where injectors win, where they stop making sense, and what the cable plant has to support.
Installation · 6 min read
Most outdoor PoE failures are mechanical, not electronic: a connector facing up, a gland that was never tightened, a ground path that does not exist. A checklist for pole-mounted runs.
Selection · 6 min read
Four ports at a gate, eight per floor, twenty-four in a riser closet — how port count, uplink and budget interact, and where the cheap option becomes the expensive one.
Selection · 7 min read
Same cameras and the same PoE power, different failure modes. The five management features that change how a camera site is run, what an unmanaged chassis still does well, and what a control plane costs to own.
Network Design · 7 min read
The uplink is where camera traffic piles up. When a 1000Base-X SFP slot earns its place over copper, what the port does — and what it does not.
Each article starts from a specification problem that turns up in project enquiries — a camera that will not boot, a link that drops at night, a run that is fifteen metres too long — and works it back to the numbers. The standard limits quoted (15.4 W, 30 W, 60 W, 100 m, 44–57 V) are published values from IEEE 802.3, not our own ratings.
Where a number depends on our hardware, it is taken from the model's specification and footnoted with the model number, so you can check it against the product page. We do not publish test figures, customer cases or prices here; those belong in a datasheet and a quotation, where they can be tied to a specific revision.