Serial communication can take many forms depending on the type of transmission mode and data transfer.
Serial communication cable types.
Serial standards rs 232 communications is the most popular method of plc to external device communications.
This serial communication standard is widely used and is often equipped on computers as standard.
The cables that carry digital video are almost invariably serial such as coax cable plugged into a hd sdi port a webcam plugged into a usb port or firewire port ethernet cable connecting an ip camera to a power over ethernet port fpd link etc.
The rs232 cable shown above gives the more likely connections seen in an rs232 cable.
The transmission modes are classified as simplex half duplex and full duplex.
Rs 232c rs 422a rs 485 are eia electronic industries association communication standards of these communication standards rs 232c has been widely adopted in a variety of applications and it is even standard equipment on computers and is often used to connect modems and mice sensors and actuators also contain these interfaces many of which can be controlled via serial communication.
Typical rs232 serial data cable.
A suitable cable is shown below.
Types of serial cables.
A serial cable is a cable used to transfer information between two devices using a serial communication protocol.
The form of connectors depends on the particular serial port used.
They are null modem and straight cable.
Most universal serial bus usb cables connect a computer with a peripheral device such as a keyboard or mouse rather than to another computer.
It has an uninsulated ground wire is not counted in the number of wires.
Transmission modes serial communication.
Other standards such as rs422 and rs423 are similar to rs232 although they permit higher transmission rates and longer cable distances.
There will be a source also known as a sender and destination also called a receiver for each transmission mode.
Usb cables feature twisted pair wiring.
To make serial communication possible between dte and dce two types of rs232 cables exist.
Rs 232 is a communication interface included under scada applications.
Shielded cable has a layer of foil that blocks signal interference from nearby equipment and devices.
Dte data terminal equipment and a common example is a computer.
However special network adapters sometimes called dongles connect an ethernet cable to a usb port indirectly.
In null modem cable the tx transmitter pin of the male connector is linked up with the rx receiver pin of the female and the rx pin of the male is connected to tx pin of the female.
Types of cables used in control communication control cables.
Control cables are used to connect instrument transformers coils of circuit breakers and contactors control switches meters protection devices and other control and monitoring equipment.
According serial data cables for these systems require the additional lines to be incorporated into the serial data cables for them to operate correctly.