4.Printer and Scanner Interfaces
A printer's interface is a combination of hardware and software that allows the printer to communicate with a computer.
The hardware interface is called port and each printer has atleast one interface. An interface incorporates several components including its communication
type as well as the interface software.
There are eight major communication types
1. Serial : Computers send one bit at a time, one after another through serial connection. The communication parameters like parity, baud should
be set on both entities before communication takes place.
2. Parallel : Parallel communication is more popular with printers because it is more faster than serial communication. In this type of communication,
printer receives eight bits at a time over eight separate wires.
Parallel uses a DB25 connection on the computer side and a oddly shaped 36 pin connection on the printer.
3. USB (Universal Serial Bus) : These can transfer data quickly with a transfer rate up to 12 Mbps and it automatically recognizes new devices.
4. Network : Network, or commonly Ethernet, connections are commonplace on network laser printers, though some other types of printers do
employ this type of connection. These printers have a Network Interface Card (NIC) and ROM-based software that allows them to communicate with networks, servers
5. Infrared : Infrared transmissions are wireless transmissions that use radiation in the infrared range of the electromagnetic spectrum. An Infrared
acceptor allows your devices (laptops, PDA's, Cameras, etc) connect to the printer and send print commands via infrared signals.
6. SCSI (Small Computer System Interface) : Laser printer, dye-sublimation printers and few other use SCSI interfaces to PC as there are
benefits like daisy chaining wherein more than one device could be on a single SCSI connection and it is easy to implement.
7. IEEE 1394 Firewire : Firewire is a high speed connection typically used for digital video editing or other high bandwidth requirements.
This interface currently supports devices with a maximum throughput of 800 Mbps and capable of speeds up to 3.2 Gbps.
8. Wireless : Wireless is the currently popular technology like infrared, Bluetooth, 802.11 etc. The information is transmitted wirelessly
through the air using radio waves and is received by the device.
Bluetooth is used to replace the cables between computers and its peripherals and they usually work over small distances of about 10 meters.
Out of these above communication types scanners mostly use USB, Parallel, SCSI, IEEE 1394/FireWire.