<div dir="auto"><div data-smartmail="gmail_signature" dir="auto"><br></div><br><div class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Thu, Oct 31, 2019, 1:07 PM Jim Ruxton via talk, <<a href="mailto:talk@gtalug.org" target="_blank" rel="noreferrer">talk@gtalug.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p><br>
</p>
<div><br>
</div>
<blockquote type="cite">
<div dir="auto">Is your user a member of the dialout group? You
can't access serial ports unless you are. <br>
</div>
</blockquote>
Yes I am a member of dialout and I have no problem when my device
uses /dev/ttyUSB0 .<br>
<blockquote type="cite">
<div dir="auto">
<div dir="auto"><br>
</div>
<div dir="auto">Also, '<span style="font-family:sans-serif;font-size:12.8px">baudrate=57142</span><span style="font-family:sans-serif">' looks a bit odd. 57600 is
more standard, but I've seen that number used for a couple
of motor controllers. <br>
</span></div>
</div>
</blockquote>
Yes this is a Dynamixel motor controller , they seem to prefer this
baud rate.<br>
<blockquote type="cite">
<div dir="auto">
<div dir="auto"><span style="font-family:sans-serif"><br>
</span></div>
<div dir="auto"><span style="font-family:sans-serif">Is there a
way you can try it without the USB extender? <br>
</span></div>
</div>
</blockquote>
I can try this later when I have access to it again but I will need
to run it eventually with the extension.<br>
<blockquote type="cite">
<div dir="auto">
<div dir="auto"><span style="font-family:sans-serif"><br>
</span></div>
<div dir="auto"><span style="font-family:sans-serif">Are you
using more than one usb serial device? If you are and they
are both Prolific devices, there is no way of telling them
apart by any device path. They will swap freely at
enumeration. Unlike FTDI adapters, Prolific have no serial
numbers. I try to avoid having two PL2303s on the same
machine, preferring a mix of FTDI, Qinheng and SiLabs. <br>
</span></div>
</div>
</blockquote>
My problem occurs when I am only using the one adapter. It is an
FTDI device.<br>
<blockquote type="cite">
<div dir="auto">
<div dir="auto"><span style="font-family:sans-serif"><br>
</span></div>
<div dir="auto"><span style="font-family:sans-serif">If a
/dev/ttyUSB0 path works then the /dev/serial/* equivalent
must work: they're symlinks to the same device. The only
time I've seen it not work was in software that hard-coded
the device path to be 12 bytes. <br>
</span></div>
</div>
</blockquote>
<p>Yes the /dev/serial equivalent works as long as it's the
equivalent of /dev/ttyUSB0 .</p>
<p>To communicate with the motor I'm using the pyax12 communication
library <a href="https://github.com/jeremiedecock/pyax12/blob/master/pyax12/connection.py" rel="noreferrer noreferrer" target="_blank">https://github.com/jeremiedecock/pyax12/blob/master/pyax12/connection.py</a></p>
<p>Thanks,</p></div></blockquote></div><div dir="auto">Persistant connections are usually managed by udisk for block devices and udev for usb. It looks to me like you need to use udevadm to retrieve the serial attributes of the device as well as a vendor id and put a rule in /etc/udev/rules.d </div><div dir="auto"><br></div><div dir="auto">udevadm info -a -n /dev/ttyUSB0 | grep '{serial}' | head -n1<br></div><div dir="auto"><br></div><div dir="auto">I pulled that command from this primer from another stepper motor setup config, looks like they are an observatory.</div><div dir="auto"><br></div><div dir="auto"><a href="https://indilib.org/support/tutorials/157-persistent-serial-port-mapping.html">https://indilib.org/support/tutorials/157-persistent-serial-port-mapping.html</a><br></div><div dir="auto"> </div><div dir="auto">I seem to recall from older serial modem usb modeswitching the connection required a serial message info type to be sent in order to handshake on connection. I cant be sure thats the case here but perhaps the examples of the rules which are used to create and define the symlink node on the above observatorys rules for persistant links can help.</div><div dir="auto"><br></div><div dir="auto">If that does help, one of the features of udev is that udevadm info --attribute-walk will list all the parent connections and you can use the actual device id and one parent id to uniquely identify and bind your adapter in the chain, when it comes to that. </div><div dir="auto"><br></div><div class="gmail_quote" dir="auto"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF">
<p>Jim</p></div></blockquote></div><div dir="auto">Russell</div><div class="gmail_quote" dir="auto"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div text="#000000" bgcolor="#FFFFFF"><blockquote type="cite">
<div dir="auto">
<div class="gmail_quote" dir="auto">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
<br>
</blockquote>
</div>
</div>
<br>
<fieldset></fieldset>
<pre>---
Post to this mailing list <a href="mailto:talk@gtalug.org" rel="noreferrer noreferrer" target="_blank">talk@gtalug.org</a>
Unsubscribe from this mailing list <a href="https://gtalug.org/mailman/listinfo/talk" rel="noreferrer noreferrer" target="_blank">https://gtalug.org/mailman/listinfo/talk</a>
</pre>
</blockquote>
</div>
---<br>
Post to this mailing list <a href="mailto:talk@gtalug.org" rel="noreferrer noreferrer" target="_blank">talk@gtalug.org</a><br>
Unsubscribe from this mailing list <a href="https://gtalug.org/mailman/listinfo/talk" rel="noreferrer noreferrer noreferrer" target="_blank">https://gtalug.org/mailman/listinfo/talk</a><br>
</blockquote></div></div>