[gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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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

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Mick]

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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

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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On Sat, Nov 5, 2011 at 12:17 PM, Mick <michaelkintzios@gmail.com> 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
>
Hi and thanks for replaying.
This cable setup is working between the 2 desktop computers
bidirectionally. So, it seems that that part I got right.
The problem is when the laptop use the same cable connection and have just
one direction.

Basically, I need to cross pin 2 and 3, and I have the setup open, so I can
cross whatever pin I want.

Regards,
Kfir

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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On Sat, Nov 5, 2011 at 12:48 PM, Kfir Lavi <lavi.kfir@gmail.com> wrote:

>
>
> On Sat, Nov 5, 2011 at 12:17 PM, Mick <michaelkintzios@gmail.com> 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
>>
> Hi and thanks for replaying.
> This cable setup is working between the 2 desktop computers
> bidirectionally. So, it seems that that part I got right.
> The problem is when the laptop use the same cable connection and have just
> one direction.
>
> Basically, I need to cross pin 2 and 3, and I have the setup open, so I
> can cross whatever pin I want.
>
> Regards,
> Kfir
>

I have checked this with another laptop, and everything works as expected.
(serial connection ttyUSB0 from laptop to ttyUSB0 or ttyS0 on the desktop1).
setserial and stty shows the same output on both laptops, so my guess, it
is something related to the USB system?!
Can someone have a guess on this?

Regards,
Kfir

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[bill.longman]

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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On Sat, Nov 5, 2011 at 9:57 PM, <bill.longman@gmail.com> wrote:

> Pardon my top post please.
>
> 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.
>
> I have connected the wires by hand, 3-2 and 2-3 but without 5.
I'll try it again today with 5 connected, and post my findings.

Regards,
Kfir

>
>
>
> -- Sent from my HP TouchPad
> ------------------------------
> On Nov 5, 2011 3:17 AM, Mick <michaelkintzios@gmail.com> 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
>

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Andrea Conti]

> I have connected the wires by hand, 3-2 and 2-3 but without 5.
> I'll try it again today with 5 connected, and post my findings.

Not having a common ground reference between the two sides could very
well cause the kind of problems you're seeing :)

andrea

Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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On Sun, Nov 6, 2011 at 3:27 PM, Andrea Conti <alyf@alyf.net> wrote:

>
> > I have connected the wires by hand, 3-2 and 2-3 but without 5.
> > I'll try it again today with 5 connected, and post my findings.
>
> Not having a common ground reference between the two sides could very
> well cause the kind of problems you're seeing :)
>
> andrea
>
> As you and bill suggested, the problem was the ground pin 5, which I
forgot about.
I now took care to connect the ground and also use it as a shield, and it
is working now.

Thank you all for your help,
Kfir

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Maciej Grela]

2011/11/5  <bill.longman@gmail.com>:
> Pardon my top post please.
>
> 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.
>

When you have a simple cable like that make sure to disable hardware
flow control on *both* sides. This is a mistake I was always making in
the past.

Best regards,
Maciej Grela

Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[bill.longman]

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Kfir Lavi]

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On Sat, Nov 5, 2011 at 2:30 PM, <bill.longman@gmail.com> wrote:

> Is there some inittab setting that's different on your laptop?
>
>
>
> -- Sent from my HP TouchPad
> ------------------------------
> On Nov 5, 2011 2:21 AM, Kfir Lavi <lavi.kfir@gmail.com> 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
>
No, it is the same as in the other laptop or servers.

Kfir

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Re: [gentoo-user] [OT] laptop desktop serial connection don't work on one direction

[Jeremy McSpadden]

My question is why the hell would you want to connect it over serial? Try ethernet, its much faster.

--
Jeremy
On Nov 5, 2011, at 4:20 AM, 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