Serial Communication RS232 & RS485

John S. Rinaldi of Real Time Automation describes serial communications RS232 and RS485.

While you're at it, don't forget to sign up for our bi-monthly newsletter:

Follow us on social media:
Instagram: @RTAutomation

[lite]

This video was very helpful. I was running into problems getting an RS232 female db25 serial Boca ticket printer to work. This video led me to investigate null modem wiring and pinouts. My problem was solved after I soldered together my own crossover (a.k.a. null modem) cable. Thanks!

[nickleclair]

This feels a bit like getting a CS lesson from Mike Ehrmantraut, awesome.

[ZEVNAtv]

You are the man!. Thanks from a Spanish Mechanical Engineer getting into electronics!

[ingenieroacevedo]

Very illustrative and clear explanation, props for that!

[sudheernorway]

this professor tried his best to make his student understand in a simple

[Javier_Saenz]

I think, when you talking about the characteristics of the RS485, you actually talking about of the RS422, RS422 is a multidrop protocol and RS485 is a multipoint protocol, where you have different transmitters and receivers and you can send and receive information from different points (transceivers). Thanks for the video

[葉東壬]

THIS IS WAY TOO USEFUL, THANK YOU SIR!

[AkinwaleIfaniyi]

Great video! Very simplified presentation of the subject.

[agstechnicalsupport]

Good video, RS232 and RS485 explained with simple words. Thank you for sharing !

[OM]

RS232: Ground is a sink for noise (noise will be Earthed), RS485: no one of the two differential lines will be grounded. You can read about PCB design to know more about grounding.

[dandavis]

I get it, generally. The one part I don't understand is how having a ground or a differential matters. Just for the sake of conversation, if we had a 1V inducement on a Tx vs Gnd line, compared to a 1V inducement on a D+ vs D- line, assuming both wires were in the same proximity, what is the difference?

[kondordv]

but, why nothing about voltage used in RS232 and RS485? It is very important.

[sauldel]

That's a great video... explains pretty much everything I was questioning my teacher. Good job.

[annonomass]

proper cable shielding is a must aswell as having dual ended chokes help alot.

[ferfr]

hey bro, these tutorials are awesome, you should create a playlist or  number each video so we can follow them in order. ;-) you have great stuff here

[renechawy]

Thank you for your time, keep up the good job

[tmc]

I'm trying to communicate with an old heathkit microprocessor trainer over rs232 but I get ascii character 152 which is the y with diaeresis or two dots above it but I should have line numbers for basic programming. Is there a software utility for troubleshooting rs232 connection? I've tried different settings in hyperterminal and PuTTy.

[barackuse]

Awesome video, thanks. One question that was not clear, how does the reflection occur? Is because of resistance built up in the cable distance? That part was a bit confusing.

[tomc]

Nice presentation. However, it gets really interesting with hardware flow control. There is not much information to be found on RTS/CTS handshake, and it can become confusing fast.

[konradb]

why in case of rs485 there's induced voltage on both wires, but in the case of rs232 it only goes induced on one? Shouldnt it be induced on all the 3 wires as they are all exposed to the same noise? And another question: In rs485 standard, is it possible to exchange data between two slaves? Can one slave ask another to send or recieve some data while it works as a transmitter? Thanks for answers in advace! Great video anyways.