Pulse Width Modulation (PWM)

Pulse width modulation is only one of a number of possibilities that can be used to convey electronic signals from one module as you call it , to the next. It works almost like frequency modulation but with the difference that coded pulses are exchanged and the code combinations are sinchronised in send speed between the modules aswell as all modules must understand the coding (language) Where FM is rather used for analogue applications, PWM gets used for digital applications. I can give you way more info but I'm not sure how much detail you want on this.

hi sir,

actually i am interested to know and understand every thing about communications, so please if u have any more informations i am ready for it but remember that i am still beginner on this matter so i can understand what u r saying if u start with basics?

you help is highly appreciated

Have a look at this.

In any communications network where there are multiple devices talkng on the same "wires", 1 device will coordinate the communications. This can be a timing beacon where each device gets a certain time slice in which to pass data, or can be something like Modbus where the slave units only communicate when they have been directly addressed.

It is not just 1 byte of information, it is a message that states a unique identifier for each device on the network.

Master: Device "Bob" (or 3 or whatever), tell me what you flow, temperature, and pressure readings are - now.

Bob: This is "Bob" my readings are: 1000,72,13 - end transmission.

All of the devices will hear the command from the master device, but because their identifier isn't "Bob", they will not answer back.

I am also interested to find a good reply. I have noticed that some PWM ICs got syn. out put for master/ slave operation, but I do not have a good circuit. Visit www.smps.us a good SMPS web site.