Recently I've had a few questions about power injectors to use with Cisco video cameras.
Of course Cisco makes power injectors for use with wireless access points, and IP phones, but we don't make any specifcally for the cameras since the cameras should work with any 802.3af compliant supply.
Internally, there is general agreement that the unified communications injector will work, and that the original wireless injectors (AIR-PWRINJ1, AIR-PWRINJ2 and AIR-PWRINJ3) do not work. I have had good luck with AIR-PWRINJ4, but have heard some reports of people who couldn't make it work in some cases. What's your experience ? Does AIR-PWRINJ4 work ? Or do you have another favorite injector you use ?
Current (Cisco and other) switches and power injectors will allow you up to 20.0w of power but there are some which will allow up to 50w. This will depend entirely on the specs of the PTZ cameras required.
If I need a power injector (aka single port Power over LAN Midspan) then my first call will be Cisco's partner, PowerDsine.
I tried using the power injectors for Cisco Aironet and it worked fine. However, there could be problems with other PoE switch because I broke a camera when I plugged it to a Nortel PoE switch. It will be much better if Cisco provides a list of power injector and PoE switch that is tested on their PoE cameras.
Not sure why they haven't released this list yet.