Me and RS232!
If you are wondering this is something new then this article is for you and If you already knew what it is, then definitely you shouldn’t miss reading . Last Summer I was very fortunate to have interned at NSTL (Naval Institute of Science and Technology) ,a R&D organization of DRDO .A team of scientists were working on a secret project which needed the support of a telecommunication team and this created an opportunity for me to work and explore few things with them. The expected delivery date of the project was around 2 weeks from then .The first few days of the project were really tough as I didn’t have much exposure towards the domain that I was working in but still its only my determination to complete this project and successfully I did .So this article is about my learning’s during this project and debunking the secret of RS232
RS232… What is it?
This isn’t something new it was introduced in 1960 and to make this term relatively simple its just a serial connection! Why don’t we remember RS232 is only because it was a older technology but what if I tell you! It is one of the most used in telecommunication industries also at one time, it was the most used form of data transmission. You will probably recognize the standard 9 pin DB9 cable that we use in our computers.
Why serial communication?
It’s one of the cheapest modes of communication that can be implemented and over long-haul communication and can provide numerous benefits.
How does it work?
RS232 Let’s try to crack this RS232-Recommended Standard 232 computer serial interface, IEEE). So, This is a communication cable, generally used to transfer and receive the serial data between two devices This cable supports both synchronous and asynchronous data transmissions RS232 transmits signals using a positive voltage for a binary 0 and a negative voltage for a binary 1.. To recapitulate :
i.Asynchronous Data Transfer is –The bits of data are not synchronized by a clock pulse.
ii. Synchronous Data Transfer is –The bits of data are synchronized by a clock pulse.
This cable works at different baud rates, such as 4,800 bits/sec and 9,600 bits/sec. The RS232 consists of two terminal devices, namely DTE and DCE. These two devices send and receive the signals. In present days, most of the PCs include two serial ports and one parallel port. These ports are used to communicate with external devices. A serial port sends and receives data one bit at a time over one wire very slowly. In the same way the parallel port also sends and receives the data over eight separate wires, and these ports are generally used to connect a printer to a personal computer. Data is transmitted serially in one direction over a pair of wires. Data going out is labeled Tx (indicating transmission) while data coming in is labeled Rx (indicating reception).
Where do we use them ? PLC machines, CNC machines, Servo controllers, Microcontroller boards, receipt printers, point of sale system (PoS) etc. In addition to communications between computer equipment over telephone lines, RS-232 is now widely used for connections between data acquisition devices and computer systems. As in the definition of RS232, the computer is data transmission equipment (DTE). However, many interface products are not data communications equipment (DCE). Null modem cables are designed for this situation; rather than having the pinto- pin connections of modem cables, null modem cables have different internal wiring to allow DTE devices to
communicate with one another.
My experience with RS232:
My project was about interfacing RS232 inside an FPGA which taught me these lessons of how important is having an update on older technology is as important as to learning new ones .These are some of the takeaways that I had over the time. Hope you had a nice time reading .
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