Lucian wrote :

> Here's a diagram of the configuration I have. In fact, I want the
> circuit to function without the MAX232 connected, but it
> doesn't. That's what I'm trying to figure out: why does now it only
> functions with the MAX232 connected to the line.

Hi !
(Refering to the attached GIF...)

I'd guess that when the PC is "idle", the MAX232 is holding
it's TX output *actively* high ("1"). That's why the slave can
not send data using it's own TX output. The slave and the
MAX232 will try to force that line in different directions.
If the MAX232 can source more current then the slave can drain,
the line will probably be kept in a high state.

What about a diod at the MAX232-TX, just as at the slave-TX ?

Jan-Erik.

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