The MOD-POE-V2 board extracts power from the UTP LAN cable network, so you can power your embedded device with 5 or 12VDC, and power and Ethernet are carried at the same cable. Note that the LAN cable should be connected to a PoE-compatible switch/router.
The MOD-POE-V2 follows the recommendations set by IEEE 802.3af-2003 standard. MOD-POE-V2 is not compatible with Olimex MOD-POE injector (because it needs higher input voltage - at least 37V DC).
MOD-POE-V2 works only in Alternative B (Mode B). Important notice: There is no galavano isolation between MOD-POE-V2's power input and output! This might be a problem if your hardware setup has more than one source of power applied at the same time! Make sure to take precautions if your hardware setup has more than one power supply (or even only ground) attached!
Si3402 PoE controller with DC-DC step down converter and PoE protocol negotiation
Power output is selectable via a switch - 5 / 12 VDC
I provide 24V to the input of MOD-POE-V2 but there is no output. What is the problem?
Si3402 would NOT work with 24V DC. The recommended voltage is 48V DC and the minimum is around 37V DC. For more info refer to Si3402-B's datasheet.
What is the maximum current output approximately?
The maximum output is close to 10W. This means ~800mA for the 12V output mode; ~2000mA for the 5V output mode.
It seems my board get damaged by MOD-POE-V2. I have MOD-POE-V2 powered via PoE and it powers another board. This other board is sometimes connected to a personal computer via USB. What could have went wrong?
There is no galvanic isolation (no optocoupler, no transfoermer, etc) between MOD-POE-V2's power input and output! This might be a problem if your hardware setup have more than one source of power applied at the same time! If the board powered via MOD-POE-V2 is also connected to a different power supply that adds a second ground (for example, if it is connected to a computers USB port or another power source) - something may get damaged during the connection! Make sure to take precautions if your setup has more than one ground! It is good idea to disconnect the connections between MOD-POE-V2 and the target, power everything and measure the voltage difference between the grounds of MOD-POE-V2 and the target (before establish the connection). If the voltage difference is too high do NOT connect the target to MOD-POE-V2 and the other power supply at the same time. Maybe try adding optocoupler, maybe try connecting the grounds first before the power, etc.
Consider using Olimex USB-ISO to protect your computer and board from this accidental overvoltage.
Does MOD-POE-V2 work in both PoE modes - A and B?
No. By default MOD-POE-V2 works only in mode B - pins 4–5 form one side of the DC supply and pins 7–8 provide the return; these are the "spare" pairs in 10BASE-T and 100BASE-TX. Mode B requires a 4-pair cable.