RS232 With Long Distance

[Suraj143]

Hi I want to transfer my RS232 data (9600bps) on 150m length.

Whats the hardware method I can use to transfer my data?

 

[BeeBop]

Hi I want to transfer my RS232 data (9600bps) on 150m length.

Whats the hardware method I can use to transfer my data?

Look into rs485; it is differential pair signaling, and will give good noise immunity over that distance. It is also easy to do - use a max485 instead of a max232 driver.

 

[Suraj143]

Hi BeeBop thanks for the input.I have no experience in MAX485.Now I have done RS232 code also I have connected my PIC output to MAX232.

Can I directly connect MAX485 to PIC to transfer long distance?

 

[blueroomelectronics]

Then use RS422. It won't require a code change.

 

[ericgibbs]

Suraj.

Use this as a ref, as Bill says RS422.

Serial Cable Length Limits (RS232, V.35, RS530, RS422/449), SCSI Cable Length Limits, Parallel Cable Length Limits

http://www.interfacebus.com/Design_Connector_RS422.html

 

[binzer]

Suraj.

Use this as a ref, as Bill says RS422.

Serial Cable Length Limits (RS232, V.35, RS530, RS422/449), SCSI Cable Length Limits, Parallel Cable Length Limits

Also if you need to go over the max length you can make a box with rx-tx pairs to extend, you just need a power source at that point. A place I worked for did this for special orders and we would have to run the system with the full cable length and monitor data errors and data retrans.

 

[Suraj143]

Ok thanks guys for giving the idea of RS422.

I searched but there is no data sheet for RS422.Did you find any data sheet?

The other thing is I'm confuse with "what is the meaning of balance line & unbalance line" in communication.In RS232 I don't know what is that balance or unbalance.

 

[BeeBop]

Ok thanks guys for giving the idea of RS422.

I searched but there is no data sheet for RS422.Did you find any data sheet?

Scroll down further on the link which Eric posted: (just click here)
EIA-422 Bus Interface Description, RS422

 

[Suraj143]

Hello BeeBop is this IC correct? MAX485? Can I do RS422 with MAX485?

 

[BeeBop]

Hello BeeBop is this IC correct? MAX485? Can I do RS422 with MAX485?

I've used the sn75174 and MAX3080s but see this page. You can get data sheets there as well:
Linear Series

also:
http://para.maxim-ic.com/en/results.mvp?fam=rs485&245=Full&793=5&252=15

and
http://search.linear.com/search?fil...xystylesheet=default_frontend&q=rs422&numgm=5

 

[Suraj143]

Ok I read many articles & got some ideas.

I want to know can I interface MAX485 with MAX232 to send long distance transmission?

 

[blueroomelectronics]

You need an RS232 to RS485 adapter.
R.E.Smith Serial Communications RS485

 

[binzer]

You need an RS232 to RS485 adapter.
R.E.Smith Serial Communications RS485

What about replacing the MAX232 with a MAX485 on the pic end then of course an adapter on the computer end, but I am sure one could be built also..

Mike