mathlaj wrote:
> Hi,
> I would like to know if this is possible to bring the TS-7200 +5VDC
> over the COM2 port (RS-232) to my custom device.
> As the COM2 is only using the pins 2,3 & 5, is there another pin that
> can be driven to the +5 VDC to bring power to the distant device??
>
> To explain a bit more what I need:
> My device communicate RS-232 with the TS-7200 and is powered +5VDC and
> need a maximum of 55mA of current, more of the time consuming near
> nothing (40uA).
>
> A MAX232 is not providing me enough current from the Rx/Tx pins
> (typically 30mA for what I read). As my device is more often sleeping
> than running, I guess I could use some capacitor, but this is not the
> path I wanna take.
> Actually, I use the 10th pin of the ribbon cable, connected to the
> +5VDC of the board, but I'd rather use a normal DE9 cable going to my
> device, as this is much more common and tougher than a ribbon cable.
The RS-232 signals RTS and DTR (outputs) are usually used for powering
devices like this. One example is the Dallas 1-Wire serial interface.
The far end device connects the CTS and DSR signals to the voltage
regulator via diodes.
So if the TS-7200 offers an RTS signal on one of it's com ports, you are
half way there.
Joel
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