How to RS232 to RS485

Understand in RS232 to RS485 convert,circuit and Specification

    I thing,you know the rs232 port that after refer it again, I will be say the rs485 , 
May be you have not still understand it in control and access its for interfacing to another hardware.


    We can interface hardware and device with RS422,RS485 port in PC programming (such as VB,VC++,.NET,
Delphi,Pascal,Linux etc.). 



So,This article help you know about information of using in RS-485.
    Most PC's have one serial ports. It has a 9 pin connector on the back of the computer. 
Computer programs can send data (bytes) to Data pin (output) and receive bytes from the receive pin
(input).  


	
 The serial port is I/O(Input and Output) device. An I/O device is just a way
 to get data into and out of a computer using. There are many types of I/O devices such as serial ports, 
parallel ports, disk drive controllers, ethernet boards, universal serial buses, etc. 

   The RS-485 Port is the most commonly used port for interfacing home made projects. 

RS232 to RS485 Converter sample Diagram - RS-485 PCI communication or card .





The converter RS232/RS485 interface allows any device using a serial RS232 to RS485. 
The RS485 was designed for the long term data acquisition and control applications. 
The original specifications (which have been overtaken by the current hardware), allows up to 32 network 
stations in the same direction, at speeds up to 10 Mbps at distances of 4,000 feet (1200 meters ). 
The link is balanced so that any electrical noise into one of the lines is also in line the other allowing the receiver
 to cancel both noise signals.






 
Map RS485 links are widely used in industrial process control where reliability is important. In addition, 
the ability to communicate over long distances at high speed is important when it comes to industrial installations 
where stations could be spread over a large area.It is very common to have a PC to monitor a process . 
PC in general have a RS232 serial port (COM port) and, therefore, there are two solutions to connect 
the computer to a RS485 network: 




one is to Plug an RS485 interface slot in a computer and the other is to convert 
the signal level coming RS232 series of computers in a port RS485 signal. 
That is what the converter does RS232/RS485.
 The converters are designed to work with the RMV Electronics I/O-485 general line stations specially built 
for process control, but they can also be used back to back and anRS232/RS485/RS232. 
In this way, two computers or devices using an RS232 serial port can communicate with each other 
to a maximum of 115,200 baud over a distance of 4,000 feet, something impossible to achieve using a RS232. 
An interesting application of using two converters RS232/RS485 back to back is when a computer must 
be connected to a I/O-232 board at a greater distance than usual. This gives very good performance 
while retaining the simplicity of our I/O-232 line boards.







RS422 Circuit Diagram
 





RS485 Circuit Diagram
 




Website Referrent/Credit
www.interfacebus.com


 RS485 & Modbus Protocol Guide