Transmit data through telephone line

[amirm2039]

Hi
I want to Transmit data through telephone line:
Boad rate >= 9600
Port of PC : RS232

So, could you guide me?

 

[FvM]

Use a modem.

 

[amirm2039]

Use a modem.

Yeah... I know! But how can I build it?
Do you know any IC that it can do that?

 

[d123]

I'm not sure (and this isn't my speciality, not that anything else is either) but, ARM devices may be able to do all that.
Broadcom chips are in routers...
BCM2835 is in Raspberry Pi type devices...

You could have a look at what people who make routers use, what people with Arduinos do, or refer to companyies like Cisco or similar to get ideas.

I agree with FvM, to make one sounds like a (possibly painful) long project otherwise, but certainly worthwhile if that's an area that interests you.

 

[FvM]

I have used ready-made modems or modem modules up to now. Modem chips are available from a number of manufacturers, e.g. silabs.com. But I don't believe that the integration effort pays unless you aou designing for large quantities production or have special requirements that aren't fulfilled by retail products (unlikely).

 

[amirm2039]

Thank you for taking this into consideration.

Now, I found an IC: CMX869B
Did you used it, or know about it?
According page 12, I think it supported 9600 data rate. what is your opinion?

PS: I want to connect a PC and uC via telephone line.

 

[andre_luis]

I had used a modem having this CMX prefix many years ago, and worked fine, but don't remember the exact P/N. This manufacturer had a development kit that allows detach the telephony module and assemble it directly on the target board. This was useful due to the circuit shown at the application note have a lot of components, and we were not finding all them, and a quick solution was to mount the module of the kit as a OEM product.

 

[FvM]

It's not clear what "telephone line" means related to the problem.

If it's a leased line respectively an isolated line in your building with a length < e.g. 1000 m, you can also use RS485 without modulation. A modem is needed for a public or private telephone line switched through a telephone office.

To be used with a leased line (no loop current, no dialtone) a modem must have a special leased line option. Most industry standard modems have.