On Wed, 2007-08-15 at 14:30 -0400, Madison Kelly wrote:
> Andrew Grimberg wrote:
> > Greetings folks,
> > 
> > Am I just blind or can I not find what type of null modem cable that I
> > need for heartbeat?  I've got several full-handshake cables that while I
> > can communicate in one direction, aren't working in the opposite
> > direction.  Anybody got a suggestion as to what type of null modem cable
> > I should be using?
> > 
> > -Andy-
> 
> Here are my notes:
> 
> P: Error:
>     heartbeat[2830]: 2007/06/26_13:27:06 WARN: glib: TTY write timeout 
> on [/dev/ttyS0] (no connection or bad cable? [see documentation])
>     heartbeat[2830]: 2007/06/26_13:27:06 info: glib: See 
> http://linux-ha.org/FAQ#TTYtimeout for details
>       Prints repeatedly in the ha.log file even when both nodes are up. You 
> can manually send data over the null modem cable.
>       NOTE: Seeing this error once when one node is down is normal!
> S: As per the referenced URL; The null modem cable you are using most 
> likely does NOT have the CTS and RTS lines connected (pins 7<->8).
>       You will need to verify this using a continuity tester. The needed 
> cable pinouts are:
>       CD    - 1 ---------\          /--------- 1 - Carrier Detect
>       RD/RX - 2 ---------|----\/----|--------- 2 - Receive Data
>       TD/TX - 3 ---------|----/\----|--------- 3 - Transmit Data
>                          +----------|--------- 4 - Data Terminal Ready
>       DTR   - 4 ---------|----------+
>       CG    - 5 ---------|----------|--------- 5 - Common Ground
>       DSR   - 6 ---------/          \--------- 6 - Data Set Ready
>       RTS   - 7 --------------\/-------------- 7 - Request To Send
>       CTS   - 8 --------------/\-------------- 8 - Clear To Send
>       RI    - 9 -]                          [- 9 - Ring Indicator (not 
> used/no connection)
>       In case my ASCII art confuses you, tie pins 1 and 6 together and run 
> them to pin 4 on the other side of each. So I could have drawn the above 
> diagram like this (Same thing just expressed differently):
>       CD    - 1 -\
>       DSR   - 6 --+--------------------------- 4 - DTR
>       RD/RX - 2 ------------------------------ 3 - TD/TX
>       TD/TX - 3 ------------------------------ 2 - RD/RX
>       DTR   - 4 ---------------------------+-- 6 - DSR
>                                                \- 1 - CD
>       CG    - 5 ------------------------------ 5 - CG
>       RTS   - 7 ------------------------------ 8 - CTS
>       CTS   - 8 ------------------------------ 7 - RTS
>          RI    - 9 -]                          [- 9 - RI (not used/no 
> connection)
>       Lastly, there is no wiring colour code. If you are making your own 
> cables, make your own colour code too!
> 
> HTH!

Turns out I've got a bad cable.  I could send in one direction, but not
the other.  All my own fault.

-Andy-

Attachment: smime.p7s
Description: S/MIME cryptographic signature

_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems

Reply via email to