At 12:33 PM 7/19/2005, Vic Fraenckel wrote:
>Given an RS232 cable with just 3 wires thus:
>
>Pin 2 - RXD
>Pin3 - TXD
>Pin5 - GND
>connected to a DB9 on a computer and going to some sort of device.
>
>1. Is this the proper way to name the wires?
>2. Does RXD imply  a signal going TO a computer FROM the device?
>3. Does TXD imply a signal coming FROM a computer TO the device?

That's usually the convention.  When I do a schematic, the signal 
names are "Me-centric".
RXD is coming to me, and TXD is coming from me.

Of course my RXD must connect with the other guy's TXD, and some 
people see that as confusing, so they want to label a given signal 
TXD, on both sides.


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