[chbot] RS232 FILTER

[Martin Towers]

The simplest do-it-today fix is to use a laptop which has no earth
connection, desktop machines always foolishly connect their interfaces
to earth.

Im am still uneasy about the earths. Is this a new problem? Did it all
work perfectly until...?
Until what? Have you moved a machine from one power socket to another?
Is there an earth wire fallen off? A loose wire in the distribution
board?

If the fault happens when just the cable is connected to the CNC
machine with nothing on the other end then the CNC has a problem. The
shielded RS232 cable should keep the signal wires quiet, if the shield
is connected.
Check that the shell of the RS232 connector is connected to the body of
the machine, especially the position sensors.

Martin

-----Original Message-----
From: Marshland Engineering <marshland at marshland.co.nz>
Reply-To: marshland at marshland.co.nz, Christchurch Robotics
<chchrobotics at lists.ourshack.com>
To: chchrobotics at lists.ourshack.com
Subject: Re: [chbot] RS232 FILTER
Date: Tue, 25 Oct 2022 18:44:08 +1300

Just a note, I'm not actually communicating with the RS232 when I have
a
fault. I download the program which takes 5 seconds and then the
machine runs
all day. The fault come up as a X Y or S travel fault not often and not
repeatable.  The fault would indicate the encoder on the drive does not
match
up to the linear scale. My gut feeling is I get a spike on the bus and
I get
the error. Remove the RS232 cable, never get a fault. The earth loop
sound
like the issue. 


_______________________________________________
Chchrobotics mailing list Chchrobotics at lists.ourshack.com
https://lists.ourshack.com/mailman/listinfo/chchrobotics
Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/
Meetings usually 3rd Monday each month. See http://kiwibots.org for
venue, directions and dates.
When replying, please edit your Subject line to reflect new subjects.