Rs232 over long distance

[dhouston]

Careful - the RS485 adapter is only half-duplex. You probably need full duplex. The latter is possible but you need different line drivers and more wires in the cable.

[Sneaky-geek]

Thanks Dave,
Will this one work? It appears to offer full duplex and is isolated, which help with all the RF floating around the site.

www.serialcomm.com/serial_rs232_converters/rs232_to_rs485_converters/externally_powered_rs232_to_4_wire_rs485_rs422_con verter/ext_rs232_to_4_wire_rs485_rs422.product_general_in fo.aspx

Thank you again.
Terry K9HA
Sneaky-geek

[dhouston]

That should work but you should consider whether the opto-isolators are adequate if you have a lot of lightning. The datasheet says they offer 2500V isolation but that's not much where lightning is concerned. RS232 to Fiber Optics would offer much better isolation.

[Sneaky-geek]

Dave,
You are correct. That would eliminate both lightning and RF problems.
At the moment, the drawback is the cost. Fiber cable is kinda steep. This is unless there is a low cost (HEY, I'm a HAM and we are noted for being stingy) source for the cable.
This is the method I would love to use.
Maybe on E-day (no copyright infringement here!).

Again, my Thanks to All.

Terry K9HA
Sneaky-geek

[Charlie]

For the distance and frequencies you are talking, cheap plastic fiber optic cables would do fine. A quick search came up with this: http://fiberopticcables.stores.yahoo...p625-stst.html You can probably do better by spending more time searching.

[Sneaky-geek]

Charlie,
I will give them a call later today.
Thank you for the link.

Terry K9HA
Sneaky-geek