You'll have too ensure that you have only three wires. Line 2 to 3, line 3 to 2 and line 5 straight through. I don't think you'll be able to get bi directional serial links if you have the other hardware lines connected.
-- Sent from my HP TouchPad
On Nov 5, 2011 3:17 AM, Mick <[email protected]> wrote:
On Saturday 05 Nov 2011 09:20:19 Kfir Lavi wrote:
> Hi all,
> I have a problem connecting my laptop to my server at home with a serial
> cable.
> I have cable end for /dev/ttyS0 and 2 cable ends for /dev/ttyUSB0.
> This lets me test the connection between all serial outputs.
> Desktop1-minicom <-> Desktop2-minicom
> works with all connections, i.e ttyUSB0 <-> ttyUSB0, or ttyS0 <-> ttyUSB0
> and viseversa.
> So when connecting 2 desktop computers everything works as expected.
>
> The problem:
> When I connect my laptop to any of those desktops, I get just one way
> connection!
> If I swap the sides of the cable, the one way connection switch side.
> The laptop doesn't have ttyS0, so it have to be connected via ttyUSB0
> When I swap sides, it is just between two usb dongles.
>
> The usb dongles are PL2303 both sides.
> Settings of minicom is 38400 8n1 Hardware Flow Control=OFF
>
> Laptop setserial:
> setserial -a /dev/ttyUSB0
> /dev/ttyUSB0, Line 0, UART: 16654, Port: 0x0000, IRQ: 0
> Baud_base: 460800, close_delay: 0, divisor: 0
> closing_wait: infinte
> Flags: spd_normal
>
> Desktop1 setserial:
> setserial -a /dev/ttyS0
> /dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
> Baud_base: 115200, close_delay: 50, divisor: 0
> closing_wait: 3000
> Flags: spd_normal skip_test
>
> setserial -a /dev/ttyUSB0
> /dev/ttyUSB0, Line 0, UART: 16654, Port: 0x0000, IRQ: 0
> Baud_base: 460800, close_delay: 0, divisor: 0
> closing_wait: infinte
> Flags: spd_normal
>
> I tried to add the skip_test but this seems to be not working.
> I'm not sure what to do next.
>
> Any help will be appreciated,
> Thanks,
> Kfir
I think that you will need the pin mapping of a 'null modem' to be able to
have bidirectional connectivity.
Have a look here:
http://en.wikipedia.org/wiki/Null_modem
I think I still have an RS-232 to D9 null modem adaptor somewhere in my bins
of spares.
HTH.
--
Regards,
Mick
