Difference between 802.3af, 802.3at and 802.3bt PoE?

IEEE has a few standards for PoE to help keep everything working properly. There are three main PoE standards, all varying in the amount of power they supply. There are 802.3af, 802.3at and 802.3bt.

All three of these are referred to as ‘auto-sensing’ PoE, which means if you plug a laptop in to a port with PoE turned on, it won’t blow the device up as a level of auto-negotiation happens between the PoE switch and device, when it asks for power.

802.3af

802.3af is also known as just ‘PoE’ on most switches, it provides up to 15.4W and is most used for less powerful wireless access points and IP cameras. VoIP phones also tend to use 802.3af to as they don’t need a massive amount of power.

802.3at

802.3at is basically the same as 802.3af, but it just provides more power, up to 30W and is generally referred to as ‘PoE+’ on most switches. The higher amount of power allows better quality cameras to be used, such as 4K cameras and PoE switches which are powered up by PoE and provide power down stream, such as the UniFi Switch Flex from Ubiquiti, it is powered by 802.3at on the uplink and can provide 802.3af PoE on four other ports.

802.3bt

802.3bt is one of the newest standards and provides up to 60W to each device it is referred to as PoE++ usually. This is used for really demanding devices, notably lighting products and screens. Ubiquiti has LED light panels for office ceilings which are powered by 802.3bt.

Software Architects — Fundamental Path knowledgebase

It has been common to see posts and articles talking about what a software architect must read and what your book library, as an architect, should include. However, no one explains how to read them or if there is a specific sequence you must follow.

Here is one article that uses this concept; Books for Great Software Architects — Fundamentals Path

https://haitham-raik.medium.com/books-for-great-software-architect-34c81fc70e12

Get file path in .net core from wwwroot folder

This is how;

public class HomeController : Controller {
    private IWebHostEnvironment _hostEnvironment;

    public HomeController(IWebHostEnvironment environment) {
        _hostEnvironment = environment;
    }

    [HttpGet]
    public IActionResult Get() {
        string path = Path.Combine(_hostEnvironment.WebRootPath, "Sample.PNG");
        return View();
    }
}

References

https://weblog.west-wind.com/posts/2020/Feb/26/Working-with-IWebHostEnvironment-and-IHostingEnvironment-in-dual-targeted-NET-Core-Projects#out-with-old-in-with-the-new-iwebhostenvironment

Lacha Pratha لچھا پراٹھا

How to make morning bread;

Ingreditents:

  1. Fine flour (fine atta)
  2. Water
  3. Crushed sugar
  4. Gulcose
  5. Milk

Mix ingredients and leave it for 20 minutes. After 20 minutes, take 100 gram bread piece. Stritch it on a plain surface, add curves to stitched bread, roll it back, add oil and leave it for another 20 minutes.

You are all set for cooking. Watch video, how to cook.