Research and Read on POE and Fibre cabling

So, how do you get beyond that 100-meter limit? Once answer is through fiber optics. Fiber optic cabling is an effective method to overcome the distance and bandwidth limitations of UTP, and media converters are a commonly used to integrate copper network equipment and fiber. Since DC power cannot be conducted over fiber, PoE media converters are the solution to extend network distances via fiber to remote IP cameras. A PoE media converter converts the fiber to copper, and sends DC power to the camera over the UTP cabling.

How PoE Media Converters Work

 On the main article image/PoE schematic that appears at right (view a larger version here), an Ethernet switch with RJ-45 ports resides in a control room or data closet. The copper UTP cabling is converted to fiber with a standard media converter. The fiber is run a long distance to the PoE media converter located near a convenient AC or DC power source, where it converts the fiber back to copper UTP. The PoE media converter also functions as a power-sourcing mini switch, and injects PoE (DC power) over the UTP cable. At the other end of the UTP cable is the IP camera, located up to 100 meters away from the PoE media converter.

PoE media converters are available with Gigabit Ethernet and Fast Ethernet data rates and can support PoE (15.4 watts) or PoE+ (25.5 watts). PoE media converters function like PoE mini-switches, and are available in a variety of multi-port configurations, including dual RJ-45 and dual fiber ports. They can support fixed fiber connectors or small form pluggable transceivers.

To understand those power specifications, it’s worth knowing that in 2003, the IEEE ratified the 802.3af PoE Standard. That standard provides up to 15.4 watts of power per port. Late in 2009, the IEEE ratified the 802.3at PoE Standard known as PoE+ that provides up to 25.5 watts of power for each port. PoE+ can be required to power IP cameras with Pan-Tilt-Zoom (PTZ) capabilities, and weather-hardened cameras used in cold environments that feature blowers and de-icers.

How to recover micro sd card without formatting

How to recover micro sd card without formatting

What can we do if we face Micro sd card has not formatted error?

Don't worry, iCare Data Recovery can help recover video photo image files off the not working micro sd card.

iCare Data Recovery software is a free micro SD card recovery program which can recover files from SD card that shows not formatted error. It helps perform micro SD card not formatted error recovery in Windows XP, Windows 7/8 and Windows Vista.

Below here are bhe corporatiion situations:

Recover files from SD card not formatted error

• Micro SD card is blank and has unsupported file system
• MicroSD card is damaged or corrupted
• > Micro SD card access is denied
• Micro SD card is unreadable / inaccessible
• Recover photos when you want to convert RAW unformatted microSD to FAT32

iCare Data Recovery software enables you to recover photos videos music from all brands of micro SD card such as Transcend, Samsung, Kingston, Lexar, SanDisk, Toshiba, etc.

    

Steps to Recover Files from unformatted micro SD card tf card in raw filesystem

Step1. Connect the unformatted micro SD card to your computer. Download and install the data recovery software. Launch the software and select a recovery module.

Step2. Choose the micro SD card and let the software scan it for lost files. You just need to wait when the software is scanning.

Step3. You can preview the files after scanning. Then, you can select the files you want to recover and save them.

Is it possible to recover data from micro sd card not formatted error?

Micro sd card not formatted is a common problem that we may meet with mobile phone. The reasons thatMicro sd card not formatted error occur are very complex, maybe the reading part or head of the micro sd card has been damaged, so it's not accessable, or you format sd card accidently or virus has attacked yourMicro sd card, it doesn't work. When you turn on your cellphone or connect the tf card to your PC, there may be an error saying that micro sd card is not formatted, do you want to format it now? In this situation, you can perform micro SD card RAW format recovery by relying on the data recovery software.

Here shows the similar error that would occur on a hard disk drive with the format error:

Format it or not? Your data is no longer accessible to you any way. Under such not formatted error message when your micro sd card or sd card is in raw format, you need a software like iCare Data Recovery to restore data from the raw format memory card tf.

Formatting Micro SD Card without Losing Data

Are you still wondering if you can format the micro SD card without losing any data when it reports not formatted error? In fact, formatting does not erase data from the SD card permanently. Here are two situations for unformatted SD card data recovery and error fixing:

1. Recover data off SD card without formatting
Usually, it is strongly recommended you to use iCare Data Recovery to get back files first of all before you can format the TF card to fix not formatted error. When all data you need has been recovered, you can format the card as you like.

2. Accidentally formatting micro SD card before data recovery
Mistakenly formatting micro SD card before getting back lost files? Can you unformat micro SD card? In this situation, the most important thing is that you should stop adding any new data to the formatted SD card. Then, you can use iCare Data Recovery to recover files from the formatted SD card too.

Use's experience:

I had once met Micro sd card not formatted error, that day I wanted to see some photos in my Micro sd card, so I excitedly plug my micro sd card into my computer, but the only thing I got is a letter saying that the micro sd card is not formatted, do you want to format it now? I tried several times, but it's still not accessable. Untill I found iCare Data Recovery, I settled the problem. It helps me recover deleted photos from memory card free.

What is Micro sd card?

Micro sd card is a kind convenient device for us to transfer things, nowadays, it's very useful for us, we may store our photos, pictures, films, musics, even our works, so it's very useful, it can store in different files.

Change file type RAW to NTFS

dEAne

abGStorage

November 11, 2010 5:12:12 AM

There are two places where we store file system information: the MBR partition Table and Volumes boot sector, When the file system information provided on these 2 sectors of disk is not good you may see chkdsk reporting raw file system (though the data is still there).

Ok try this one mount the drive as a slave inside the computer and see if you can repair the partition table:

Download the Windows version of TestDisk. http://www.cgsecurity.org/wiki/TestDisk
Unzip the downloaded file to your C: drive and open C:\testdisk-6.8\win > double click " testdisk_win" (the program doesn't have to installed).

A. At the first window select “No Log” and press the <Enter> key.
B. Select what drive to analyse, choose “Proceed” and <Enter>.
C. Select partition type – Intel if it’s a PC.
D. Select “Analyse” then <Enter>. The drive/partition will be analysed.
E. Select “Proceed” at the next screen, then <Enter>.
F. Press “Y” if the partitions were created under Vista – “N” if not.
G. TestDisk should say “Structure OK”. Choose the drive/partition to fix. Then press <Enter>.
H. Select “Write” and press <Enter>.
I. Press “Y”.
J. Press <Enter> and close TestDisk. Reboot the computer.

My external HD is asking to format

1) HD keeps asking me to format it.

http://www.tomshardware.com/answers/id-1719092/format.html

*best solution
-------------------------------
lonewolf7
Don't worry all your data has been fine. It's a file system error. Windows can't find out what to do with it. Try this.

Plug in the drive, bring up CMD, type chkdsk O: /f/r (O is the example drive letter yours may be different). Win will rebuild the file system and all will be fine.
If all fails than try this data recovery software.

http://www.cgsecurity.org/wiki/PhotoRec

Good luck.
-------------------------------
open command prompt
"C:\> My computer"  *not always appear MyComputer, it can be your name or your computer's name

then type "cd.. " to go back to root file ,type "cd.. " many time until it appears "C:"

then type "C: chkdsk O: /f " and enter
Command prompt will fix your error as below pic.

Good luck! but remember this error may happen again, so you need to get new drive to transfer your data or transfer your data another drive. 

2) My external HD is asking to format

http://www.tomshardware.com/forum/265611-32-external-format

3) My External Hard Drive is not recognized by my computer
https://www.hgst.com/support/faqs/my-external-hard-drive-not-recognized-my-computer

4) PhotoRec, Digital Picture and File Recovery

http://www.cgsecurity.org/wiki/PhotoRec

TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. It can also be used as a communications protocol in a private network (either an intranet or an extranet).
TCP/IP is a two-layer program. The higher layer, Transmission Control Protocol, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message.

The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message. Even though some packets from the same message are routed differently than others, theyll be reassembled at the destination.

TCP/IP uses the client/server model of communication in which a computer user (a client) requests and is provided a service (such as sending a Web page) by another computer (a server) in the network. TCP/IP communication is primarily point-to-point, meaning each communication is from one point (or host computer) in the network to another point or host computer.


Reference

What is a RS232 to RS485 converter?

The main differences between these RS232 to RS485 converter units are that some of them can have a DB9 connector whereas others have a terminal screw header or RJ11 connector, some are isolated some are not, some has more than one RS485 port, some has LED lights for indicating RX/TX data flow, some are port-powered and some needs an external power supply, some are industrial strength, some are consumer products.

The RS232 to RS485 itself, regardless of what model you choose, is simply a device which can convert standard RS232 data signals into RS485 signals and vice versa. Most RS232 to RS485 converters can convert data in both directions, from RS232 to RS485 and from RS485 to RS232, this is also called a bi-directional converter.


When should I use a RS232 to RS485 converter?

RS232 to RS485 converters are mostly used in industrial and commercial environments. The reason is that the RS485 converter can be used for multi-drop networks, meaning that you for example can connect multiple RS485 devices to one computer. Up to 32 devices can be connected in one network to communicate on a single pair of wires (plus a ground wire), and the number can even be increased by using RS485 repeaters. This type of communication is called half-duplex communication. Most quality RS485 converters can communicate in this manner of up to 4000 feet (1200 meters). The RS485 converter is also fairly resistant to noise which is one more reason why it is favored in industrial environments.
Examples of uses for a RS232 to RS485 converter could be for connecting cameras, scales, meters, scanners, PLCs or most other industrial equipment to a computer.


Connecting a RS232 to RS485 converter.

The RS232 to RS485 converter can be used for point-to-point connections (connecting one RS232 to RS485 converter directly to another RS232 to RS485 converter) and point-to-multipoint networks (connecting one RS232 to RS485 converter to multiple RS232 to RS485 converters.
In a RS485 network only one slave and one master can communicate at a time, either transmitting or receiving, but not at the same time, so you might wonder how this is accomplished. Simply speaking the slaves (also called nodes) must be addressed, for example node 1 has address 001, node 2 has address 002 and so forth. These addresses are usually assigned and controlled by software, either the software running at the RS485 master (PC), or software programmed in each of the slaves. Sometimes the equipment connected at the RS485 slaves is addressable by hardware instead of software. Finally, some RS232 to RS485 converters are addressable (by DIP switches) itself, this is however not used very often.



Source

Interfacing the Serial / RS232 Port

The Serial Port is harder to interface than the Parallel Port. In most cases, any device you connect to the serial port will need the serial transmission converted back to parallel so that it can be used. This can be done using a UART. On the software side of things, there are many more registers that you have to attend to than on a Standard Parallel Port. (SPP)

So what are the advantages of using serial data transfer rather than parallel?

1.Serial Cables can be longer than Parallel cables. The serial port transmits a 1 as -3 to -25 volts and a 0 as +3 to +25 volts where as a parallel port transmits a 0 as 0v and a 1 as 5v. Therefore the serial port can have a maximum swing of 50V compared to the parallel port which has a maximum swing of 5 Volts. Therefore cable loss is not going to be as much of a problem for serial cables than they are for parallel.

2.You dont need as many wires than parallel transmission. If your device needs to be mounted a far distance away from the computer then 3 core cable (Null Modem Configuration) is going to be a lot cheaper that running 19 or 25 core cable. However you must take into account the cost of the interfacing at each end.

3.Infra Red devices have proven quite popular recently. You may of seen many electronic diaries and palmtop computers which have infra red capabilities build in. Therefore serial transmission is used where one bit is sent at a time. IrDA-1 (The first infra red specifications) was capable of 115.2k baud and was interfaced into a UART. The pulse length however was cut down to 3/16th of a RS232 bit length to conserve power considering these devices are mainly used on diaries, laptops and palmtops.

4.Microcontrollers have also proven to be quite popular recently. Many of these have in built SCI (Serial Communications Interfaces) which can be used to talk to the outside world. Serial Communication reduces the pin count of these MPUs. Only two pins are commonly used, Transmit Data (TXD) and Receive Data (RXD) compared with at least 8 pins if you use a 8 bit Parallel method (You may also require a Strobe).

**Reference**

http://iie.fing.edu.uy/~nantonie/Integrados-Componentes-Docs/PC/Conectores&Interfaces/RS232/RS232_5/serial.html