In this Wikipedia article on RS-232

https://en.wikipedia.org/wiki/RS-232

the word protocol is used only four times, and never with reference to RS-232.

The standard does not define such elements as the character encoding(i.e.ASCII,EBCDIC, or others), the framing of characters (start or stop bits, etc.), transmission order of bits, or error detection protocols.

Equipment using this protocol must be prepared to buffer some extra data, since the remote system may have begun transmitting just before the local system deasserts RTR. (with reference to RTS, CTS, RTR)

Synchronous clocking is required for such protocols as SDLC,HDLC, and X.25. (with reference to Timing signals).

Some simply display the signals as waveforms; more elaborate versions include the ability to decode characters in ASCII or other common codes and to interpret common protocols used over RS-232 such as SDLC,HDLC,DDCMP, and X.25. (with reference to serial line data analyzers).

The conclusion is that the Wikipedia article calls RS-232 a standard and not a protocol.

 

Can we not use the word "protocol" for describing RS-232 because it confuscates the issue? We can use the word "standard" instead. But that simply replaces one word with another that has the similar meaning.

Once a person understands the engineering difference between a standard and a protocol I'm in basic agreement. There are standard protocols but not all standards (ISO 216) are protocols. We implement a protocol and comply with a standard.

 

Once a person understands the engineering difference between a standard and a protocol I'm in basic agreement. There are standard protocols but not all standards (ISO 216) are protocols. We implement a protocol and comply with a standard.

We implement a protocol and comply with a standard.
We implement a standard and comply with a protocol.

What's the difference?

In my mind, the latter is the correct statement.

To clarify, a standard is an agreement.
You obey the protocol in order to make things work.

 

We implement a protocol and comply with a standard.
We implement a standard and comply with a protocol.

What's the difference?

The English language as used in formal engineering documents.

Non-compliance to standards is what the ISO auditor will hit you with.

 

The English language as used in formal engineering documents.

Yell it give's u maybe and I think to fall back on.

The Ts problem here is hardware and software
Some Hardware is hardwired for RS-232

The protocol the TS is thinking about is the fact that it does follow a protocol

A system of rules that explain the correct conduct and procedures to be followed in formal situations

 

I think the TS has run for the hills... Information overload..

 

The English language as used in formal engineering documents.

Yell it give's u maybe and I think to fall back on.

The Ts problem here is hardware and software
Some Hardware is hardwired for RS-232

The protocol the TS is thinking about is the fact that it does follow a protocol

I think the reason he was having problems was because the jumble of terms used make is easy to get confused if you don't already have experience. There is a lot of information about RS-232 and all the connecting hardware/software that's been generalized into a big heap that makes it difficult to parse exactly what aspect of that big heap a beginner is talking about when they say the word protocol.

 

START + 8 BITS + STOP About all you need to know and hardware setup or if you bit bang it's got match baud‐rate.
Hardware has to fit clock some can auto baud.


Cross your TX and RX lines .

 

START + 8 BITS + STOP About all you need to know
.

Then of course there is the options of:
Transfer speed
Data Bits #
Stop bits #
Parity
Flow Control.
SW or HW handshake.
Null Modem Mode etc, etc.
Max..

 

START + 8 BITS + STOP About all you need to know and hardware setup or if you bit bang it's got match baud‐rate.
Hardware has to fit clock some can auto baud.


Cross your TX and RX lines .

That's the easy interface/data-link part. Many of the questions we see here are about actual protocols like NMEA_0183 at the higher levels on things like GPS modules.

 

RS-232 protocol START + 8 BITS + STOP the rest becomes something else.

 

The Ts problem here is hardware and software
Some Hardware is hardwired for RS-232

That's what i am looking for, This page say its protocol https://en.wikibooks.org/wiki/Embedded_Systems/Common_Protocols

this page say chip https://robu.in/product/rs232-ttl-s...MIwLiUkLHu2QIVwxaPCh3XZQ7lEAQYASABEgJPJvD_BwE

Does protocol perform on chip ? Does uart need maxrs2322?

 

Which part of the "protocol" are you referring to?

1. UART
2. RS-232 receiver/driver
3. DCE/DTE communications
4. Data encapsulation

 

Which part of the "protocol" are you referring to?

1. UART

I am looking for Uart protocol

What is difference between Uart of microcontroller and Uart program code ?

 

The UART protocol is implemented in the UART.

What is UART program code?
Post an example.

 

The UART is Hardware [ logic] within the MCU
The UART code is the sequence of commands, the MCU uses to initialises the UART settings, baud rate etc and and also Sends and Receives data from the outside world connection.

 

There is something called "bit banging".

If you do not have hardware UART you can still send and receive UART "protocol" using software "bit banging".
Is this what you are referring to?

 

I think what your really hung up on is hardware the max 232 is a dumb chip so to say it just changes the voltage levels to work with the pc.
Now days thats not used much most pc dont have comports no more.

So we use a usb to serial adapter.
I dont think ive used a max 232 in 8 years lol

You computer handles the uart from
The usb to serial and it gives you the voltage levels your uC is needing.

5 volt or 3.3 for most uC

 

Adding my 2¢ to the confusion:

• It's always been my impression that RS232 referred to the electric signal levels used to communicate between devices, just like RS422 and RS485.
• UART is the normal protocol used in both RS232 and RS422/RS485 transmissions, but a different protocol can easily be used using same electrical signals.

 

I was sorry to see it replaced by USB, it is handy for long distance shop use, I recall using LSI UART ic's in conjunction with MC1488/89 to implement RS232 level.
Many MoBo's such as Asus, still have the port on the board should it be required.
Max.