2013年8月27日 星期二

關於 PoE 及 Injector/Splitter 的分別



PoE 全名Power Over Ethernet, 即平時我們使用的Network Cable (CAT5e) 除資料傳輸外還提供電力供應

一個完整的PoE Network, 本身應該有一隻PoE Switch這樣便可著有一條Lan線直接接駁到包含有PoE功能 Wi-Fi AP, IP Cam 或SIP Phone上, 好處在於以往安裝Wi-Fi AP時由於AP需罷放一個合適的地方以Cover整個位置, 但由於這個所謂合適的地方往往是沒有電源插蘇, 需要額外安裝電源插蘇或拉多一條電源線相當麻煩

PoE 的好處
1. 著由一隻PoE Switch可管理好多隻 PoE 的裝置
2. 如有UPS提供電源給PoE Switch相等如UPS提供了所有PoE設備的電力保障
3. 謀些程狀底下容易Reset電源, 如IP Cam或AP 安裝在天花板上或不容易接觸的地方, 需要reset電源時, 其實只需在PoE Switch上plug and unplug便可

使用PoE Switch時亦需注意PoE Switch的電源輸出是否足夠PoE設備所使用, PoE Switch的價錢亦不便宜!




PoE Injector
 - PoE Injector可參照下圖, 把沒有提供電力的CAT5線接駁後, 再轉換為PoE, 主要用途是當你沒有PoE Switch但同時需要連接到 PoE Device
(注意有些Wi-Fi Router如 TP-Link隨router本身會附有 PoE Injector, 這個Injector不可使用在其他品牌的設備上, 好大機會出現電壓問題而損壞)

PoE Splitter
 - PoE Splitter 可參照下圖, 主要是把PoE連接到你的非PoE Device


2013年8月19日 星期一

奠儀 及 禮金傳統上寫法應如何書寫


Apple Mac OS X Hotkey and BootCamp

HotKey

Reset PRRAM
 - Turn On Mac
 - Press 4 Key and Hold (Option)+(Command)+(R)+(P)
 - Wait Restart 3 times and boot sound
 - Release Hold Key

Boot Internet Recovery  (Recovery / Reinstall Mac OS)
 - Hold (Option)+(Command)+(R) around 20-30 sec, waiting screen come out.
 - You can connect to Wi-Fi and download Recovery from Internet
 - You can dump harddisk data to Image store to your external harddisk
 - You can get the OS from internet and install again

Boot Menu (Boot from USB, CDROM or Other)
 - Turn on PC
 - Hold (Option)

Boot Safe Mode
 - Turn on PC
 - Hold (Shift) Key

Full Screen Capture
Command + Shift + 3

Select Area Screen Capture
Command + Shift + 4 > Mouse Select Area

*** Command Key = Apple Key ***

BootCamp
What is BootCamp :
BootCamp is a function allow you install Microsoft Windows on your Mac with or without Mac OS.

License :
BootCamp is a tools to help you install the Microsoft Windows not include any Windows License, you should purchase Windows on online store or retail store.

What kind Windows allow to install on my Mac. If you need to purchase the Windows License, you should check which Windows OS allow install on your Mac.
https://support.apple.com/en-hk/HT204048

What should I need to prepare :
1. Your Mac : )
2. Internet Connection for download BootCamp file
3. Windows Source File Image (It require the ISO CD Image file, not CD)
4. 8GB USB Drive

Flow & Step (Official Guide link : http://www.apple.com/support/bootcamp/)
1. Plug the 8GB USB Drive, it should use FAT format
** if you got error on creating drive or you want to format to FAT, you can open Finder > Your Mac > Application > Utility > Disk Utility > Erase and choose FAT

2. Get ready the Windows ISO image file, if you only have CD, your should make a ISO image from CD.

3. Open Finder > Your Mac > Application > Utility > BootCamp
 -  You will see 3 checkbox :
 -  The first is create Windows Installation USB, this action will format your USB drive.
 -  Second is download BootCamp tools and software from internet to your USB, this action will not erase any file from USB,
 - The last is start the Bootcamp install or remove Microsoft Windows, you should use third options to install the Microsoft Windows. because direct boot from CDROM or USB your Mac keyboard and touch pad may not working, that mean you can't install the windows.

 - If you do it at first time, pleases check all box create Disk image to your USB, download driver and start the installation.

Remark : Don't use the BootCamp USB created by another Mac, it will got problem on installation such as keyboard mouse malfunction.

4. Start to install BootCamp will ask the size partition for Windows, if you just want Microsoft Windows on your Mac, please give it half half or any is ok, you can remove all partition on Windows Installation, then it will remains Windows OS only.

Q&A :
Q: After install how can i boot back MacOS
A: Turn On your Mac with hold "option" key, if will pop-up boot menu for you

Q: After bootcamp with dual OS, how can i remove Microsoft Windows, remain Mac.
A: On Mac bootcamp third option you can remove Windows

Q. After bootcamp with dual OS, how can i remove Mac remain Windows.
A. you can just simple remove the Mac OS partition on Windows, but combine the free space on windows you should try "Control Panel > Administrative Tools > Computer Management > Disk Management", i did not test, if can't combine the front free space to windows partition, you should find third party software to combine it.

Q. After bootcamp and only Windows only, how can i install Mac OS
A. You can use Internet Recovery to restore the Mac OS like new purchase status, but you can't add Mac OS on existing Windows.