Can I connect two Sun's via serial ports? - SUN

This is a discussion on Can I connect two Sun's via serial ports? - SUN ; I'm trying to think of a way to run two machines in a garage, such that I can sort out problems on the other via console access using a serial port. This is basically the setup, with 3 machines. 1) ...

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Thread: Can I connect two Sun's via serial ports?

  1. Can I connect two Sun's via serial ports?

    I'm trying to think of a way to run two machines in a garage, such that
    I can sort out problems on the other via console access using a serial
    port.

    This is basically the setup, with 3 machines.

    1) House (U80)
    2) Garage (SS20)
    3) Garage (U60).

    If the SS20 in the garage has a problem, I'd like to ssh from the U80 in
    the house to the U60, then tip to the SS20 to get console access.

    If the U60 in the garage has a problem, I'd like to ssh from the U80 in
    the house to the SS20 and tip to the U60 to get console access.

    That way, as long as the U60 *or* the SS20 is working, I can sort out a
    problem on the other, without falling over all the junk in my garage.

    Would this work if both the SS20 and the U60 are connected via serial
    port A? I don't think it will (or at least not reliably), since if
    neither have a keyboard they will both send data out the serial port
    when booting and so interfere with the other.

    Perhaps a cross-over would work.

    Serial port A on SS20 connected to serial port B of U60
    (to get console access on the SS20)

    Serial port A of U60 connected to serial port B of SS20.
    (to get console access on the U60)

    Too bad I don't have one of those special SS20 cables, but I could make one.

    I'm not bothered about problems on the U80 - I can sort them out in the
    comfort of my own home, without freezing to death in the garage!

    I don't have a terminal server.
    --
    Dave K

    http://www.southminster-branch-line.org.uk/

    Please note my email address changes periodically to avoid spam.
    It is always of the form: month-year@domain. Hitting reply will work
    for a couple of months only. Later set it manually. The month is
    always written in 3 letters (e.g. Jan, not January etc)

  2. Re: Can I connect two Sun's via serial ports?

    Dave writes:
    > Serial port A on SS20 connected to serial port B of U60
    > (to get console access on the SS20)
    >
    > Serial port A of U60 connected to serial port B of SS20.
    > (to get console access on the U60)


    Yes, that should solve the problem.

    > I don't have a terminal server.


    I've seen them listed on the web for around $200 for two ports.
    Search around with google. Another option is to get an old PC and run
    Solaris x86, *BSD, or Linux on it, though that's certainly more
    effort.

    I've also seen them on eBay. There's a pretty healthy market for used
    terminal servers.

    --
    James Carlson, KISS Network
    Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
    MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677

  3. Re: Can I connect two Sun's via serial ports?

    James Carlson wrote:

    >>Serial port A on SS20 connected to serial port B of U60
    >>(to get console access on the SS20)
    >>
    >>Serial port A of U60 connected to serial port B of SS20.
    >>(to get console access on the U60)


    Get an old pc and install a version of Linux. Search in ebay a
    multiserial card where you can attach all your servers and transform it
    like a terminal concentrator

  4. Re: Can I connect two Sun's via serial ports?

    Fabrizio Imbroglia wrote:
    > James Carlson wrote:
    >
    >>> Serial port A on SS20 connected to serial port B of U60
    >>> (to get console access on the SS20)
    >>>
    >>> Serial port A of U60 connected to serial port B of SS20.
    >>> (to get console access on the U60)

    >
    >
    > Get an old pc and install a version of Linux. Search in ebay a
    > multiserial card where you can attach all your servers and transform it
    > like a terminal concentrator


    Thanks for the idea, but I'd rather use the Suns I have. A terminal
    server would be an ideal solution, but one I'm not going to invest in
    immediatly.

    --
    Dave K

    http://www.southminster-branch-line.org.uk/

    Please note my email address changes periodically to avoid spam.
    It is always of the form: month-year@domain. Hitting reply will work
    for a couple of months only. Later set it manually. The month is
    always written in 3 letters (e.g. Jan, not January etc)

  5. Re: Can I connect two Sun's via serial ports?

    Dave wrote:
    > It's just a lot more convenient if I can avoid any additional hardware.
    > I think a simple serial cable can work. On the SS20 the two serial ports
    > are in the one connector - I suspect in the U60 they are separate, I
    > can't recall. So a Y-cable, with both serial ports wired on the SS20
    > plug, and two connectors on the U 60, will allow either machine to have
    > console access to the other, which is enough really.


    Yes, the U60 has two separate DB-25F ports while the SS20 combines them
    into one (at least that is what I find on our E220R which uses the U60
    motherboard).
    Connecting A to B between both systems will allow "tip hardwire" to
    connect to the console port on the other system.

    I wouldn't pay $200 for a Y cable - I made my own when we were still
    using an SS20. 3x DB-25F (solder type if you can solder, crimp pin type
    if you have a crimper [the only type that would probably be of no use
    would be IDC crimp type]), 3x backshells plus two lengths of 3 to 8
    core cable should not set you back too much.

    A quick Google located the following:

    The pin numbering for the DB25 (female) connector marked
    as 'A/B' on the back of the SparcStation 20 is as follows:

    1 1 1 1
    3 2 1 0 9 8 7 6 5 4 3 2 1
    +---------------------------------------+
    | x x x o o x x x x x x x o |
    \ x x o o o x x x x x x x /
    \-------------------------------------/
    2 2 2 2 2 2 1 1 1 1 1 1
    5 4 3 2 1 0 9 8 7 6 5 4

    Reprinted from the Sun Microsystem Inc.'s
    Desktop SPARC Hardware Owner's Guide (Dec '92).
    The following is the pinout of the Serial Port A/B connector:

    Pin Circuit Signal Direction Description
    --- ------- ------ --------- -----------
    1 none none -- not connected
    2 BA TD output Transmit Data, Port A
    3 BB RD input Receive Data, Port A
    4 CA RTS output Request to Send, Port A
    5 CB CTS input Clear to Send, Port A
    6 CC DSR input Data Set Ready, Port A
    7 AB SG -- Signal Ground
    8 CF DCD input Data Carrier Detect, Port A
    9 none none -- not connected
    10 none none -- not connected
    11 SCD SDTR input Data Terminal Ready, Port B
    12 SCF SDCD input Data Carrier Detect, Port B
    13 SCB SCTS input Clear to Send, Port B
    14 SBA STD output Transmit Data, Port B
    15 DB TC input Transmit Clock, Port A DCE source
    16 SBB SRD input Receive Data, Port B
    17 DD RC input Receive Clock, Port A
    18 SDB STC input Transmit Clock, Port B
    19 SCA SRTS output Request to Send, Port B
    20 CD DTR output Data Terminal Ready, Port A
    21 none none -- not connected
    22 none none -- not connected
    23 none none -- not connected
    24 DA TC output Transmit Clock, Port A DTE source
    25 DA TC output Transmit Clock, Port B DTE source


  6. Re: Can I connect two Sun's via serial ports?

    David Wilson wrote:

    > Yes, the U60 has two separate DB-25F ports while the SS20 combines them
    > into one (at least that is what I find on our E220R which uses the U60
    > motherboard).


    Although since they are probably not on the motherboard, it might not be
    the same. Still, a look in the manual will show - less hassle than
    climbing over all the junk in my garage to get to the server behind the
    lot !!

    > I wouldn't pay $200 for a Y cable


    Me neither. Although I have not looked myself, the price of SS20's has
    fallen to close to zero, so I doubt the Y-cable fetches much now.

    Annoying thing is I had one at one point (bought via eBay) but sold it
    (again via eBay). But in this case making my own would be better, as I
    can make it 5~10 meters long, so save sticking other cabls on the end.
    You can be your life I'll be able to find the Y, but not the long
    cables, or be able to find the long cables, but not the Y. But doing it
    myself I can make the Y 5~10 m and know it will work.

    Not sure of any length restrictions on serial ports. I would think at
    9600 bps you can go a pretty long way, but I'll check.
    > I made my own


    Thanks, I'd do that too. It

    --
    Dave K

    http://www.southminster-branch-line.org.uk/

    Please note my email address changes periodically to avoid spam.
    It is always of the form: month-year@domain. Hitting reply will work
    for a couple of months only. Later set it manually. The month is
    always written in 3 letters (e.g. Jan, not January etc)

  7. Re: Can I connect two Sun's via serial ports?

    On Thu, 12 Jan 2006, Dave (from the UK) wrote:

    > When I get some full time employment, I'll buy one, but until I get a job,
    > that is pretty low on my priority list!


    I don't blame you! Mine was a freebie from the ISP I used to work at.

    --
    Rich Teer, SCNA, SCSA, OpenSolaris CAB member

    President,
    Rite Online Inc.

    Voice: +1 (250) 979-1638
    URL: http://www.rite-group.com/rich

  8. Re: Can I connect two Sun's via serial ports?

    Dave writes:

    >It's just a lot more convenient if I can avoid any additional hardware.
    >I think a simple serial cable can work. On the SS20 the two serial ports
    >are in the one connector - I suspect in the U60 they are separate, I
    >can't recall. So a Y-cable, with both serial ports wired on the SS20
    >plug, and two connectors on the U 60, will allow either machine to have
    >console access to the other, which is enough really.


    They're seperate on the U60.

    Casper
    --
    Expressed in this posting are my opinions. They are in no way related
    to opinions held by my employer, Sun Microsystems.
    Statements on Sun products included here are not gospel and may
    be fiction rather than truth.

  9. Re: Can I connect two Sun's via serial ports?

    Dave (from the UK) wrote:

    > David Wilson wrote:
    >
    >> Yes, the U60 has two separate DB-25F ports while the SS20 combines them
    >> into one (at least that is what I find on our E220R which uses the U60
    >> motherboard).

    >
    >
    > Although since they are probably not on the motherboard, it might not
    > be the same. Still, a look in the manual will show - less hassle than
    > climbing over all the junk in my garage to get to the server behind
    > the lot !!
    >
    >> I wouldn't pay $200 for a Y cable

    >
    >
    > Me neither. Although I have not looked myself, the price of SS20's has
    > fallen to close to zero, so I doubt the Y-cable fetches much now.
    >
    > Annoying thing is I had one at one point (bought via eBay) but sold it
    > (again via eBay). But in this case making my own would be better, as I
    > can make it 5~10 meters long, so save sticking other cabls on the end.
    > You can be your life I'll be able to find the Y, but not the long
    > cables, or be able to find the long cables, but not the Y. But doing
    > it myself I can make the Y 5~10 m and know it will work.
    >
    > Not sure of any length restrictions on serial ports. I would think at
    > 9600 bps you can go a pretty long way, but I'll check.
    >
    >> I made my own

    >
    >
    > Thanks, I'd do that too. It
    >

    The RS-232C standard limits you to 50 feet of cable. If you use good
    quality, low capacitance cable and don't run it too close to the
    fluorescent lights, you might get up to 1000 feet to work.

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