This depends on the total output power of the MikroTik PoE device, for example: A PoE device has a total output power of 54W and you want to power several cameras that support PoE power and each camera requires 17W, then you can power 3 cameras; The number of PoE ports that the equipment has must also be considered.

The number of devices you can power over Power over Ethernet (PoE) using a MikroTik device with PoE support depends on several factors, including the specific model of MikroTik, the PoE capability of the device, and the power consumption of the devices being powered. They are going to connect.

Here's an overview of how to determine how many devices you can power:

1. PoE Type and Available Power:
   • Passive PoE: Some MikroTik devices offer passive PoE, which generally supplies a fixed voltage (such as 24V) without negotiation between the source device and the receiving device. The amount of power available for passive PoE is generally limited to the total power budget of the MikroTik device.
   • 802.3af/at (Active PoE): Other models can support active PoE, which follows the IEEE standard and can provide different power levels (up to 15.4 W per port under 802.3af and up to 30 W per port under 802.3at) with negotiation capability.
2. Number of PoE Ports:
   • Check how many of your MikroTik device's Ethernet ports are PoE enabled. Not all ports on a MikroTik device might support PoE, depending on the model.
3. MikroTik Device Power Budget:
   • Each MikroTik device has a total power budget that it can distribute among its functions, including PoE. Make sure you know the total watts your MikroTik equipment can deliver over PoE.
4. Power Consumption of the Devices to Connect:
   • You should consider the power consumption of each device you plan to connect. This value is usually found in the product specifications. Add up the consumption of all PoE devices to ensure that it does not exceed the total power budget available on your MikroTik.

For example, if you have a MikroTik CRS112-8P-4S-IN, it has 8 PoE ports with support for 802.3af/at active PoE. If each connected device consumes 10W, you could, in theory, connect up to 7 devices, assuming the switch can supply a total of up to 70W in PoE.

It is always crucial to check the technical specifications of the specific MikroTik model you are using to ensure you meet the power requirements and avoid overloading the system. Additionally, it is good practice to leave a small power margin as a precaution.