How to do reverse Engineering On RS232 and RS485

[narindia16]

rs232 reverser

Hello Friends,

I want ur advice on reverse engineering technique of RS232 and RS485 ports. Suppose we have connected a device (LED display in my case) on computers port i want to read the information being sent on that ports.

In my case a computer program is sending some information and led display board is displaying that. I want to know its protocol. Tell me what is the most effective way to read that information???

Waiting for your response guys........

 

[sau_sol]

rs485 reverseing

Connect another cable between the two connectors

i.e connect Rx of another COM port to the Tx of the data sent by PC to what PC is sending
or connect Rx of another COM port to Tx of the Device (in u r case LED blink device) to see what is the response

Added after 1 minutes:

Connect another cable between the two connectors

i.e connect Rx of another COM port to the Tx of the data sent by PC to what PC is sending
or connect Rx of another COM port to Tx of the Device (in u r case LED blink device) to see what is the response


If you are not getting data try changing Baud rate, Or parity setting so you will get the proper setting of data communication between the two devices

 

[narindia16]

reverse engineer rs232

Thanks a lot for the reply.

I know this but i want to know how i will see the response??? suppose i connected my computer inbetween that computer(sending data) and the device........how i will trace the response........actually i want to know the protocol........

 

[sau_sol]

reverse engineer rs232 input

Did yo received any data using this method

if yes then post that data here so someone will find the protocol
but the electrical connector is of RS-232 compatible
and for RS485 there are only 2 wires

 

[narindia16]

rs232 reverse type cable

No! till now i have not done this........but i need to do this......in which software i can see the response?

 

[sau_sol]

rs485 howto

in windows there is inbuilt Hyper terminal software
through which you can do this
in Linux you can use Minicom

but there are also lot of software available for serial port communication

 

[Prabakaran]

revers engineering rs232

Hi I Upload this software for monitoring the data that can be received through the COM Port with variable Baud Rate

 

[yashrolyan]

what is rs232&rs485

keep one thing in mind that by monitoring/seeing the received/sent data on other place(like u said to see on another pc), u can know the software protocol of the string which is being sent/received (string protocol)between two devices but can not know the type of hardware platform used(i.e. RS232 or RS485).

RS232 and RS485 are only the different ways to send a serial any string (consider it like a hardware platform containing some wires on which a serial string will travel).

if u really want to know the hardware platform then check its wire connections. both protocol have different types (like for full duplex RS232 have at least 3 and RS485 at least 4)or check the voltages b/w the wires (both protocol have different voltage levels)

 

[narindia16]

rs232 reverse engineeing

Thank you Guys....... you really helped me a lot..........i will try the way you suggest

 

[madicalphy]

rs232 reverse

Expansion of Input and Output (I/O) Lines of a micro-controller and method of communications, please have look on this.
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simple introduction of rs-485 protocols,
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and

RS232 to RS485 converter related information on this page.
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