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LLA FAQ

This is an attempt to answer some common questions about LLA and the LLA Live CD. For a introduction, read the tutorial.

What protocols / devices are supported ?

How is LLA Licenced?

LLA is licenced under the GPL. This means you are free to use it in both commercial and non-comercial applications. The LLA library is licenced under the LGPL, so you can call it from other applications that are closed-source.

How do I use the Enttec Open DMX Device?

You need to specify this at boot time. At the boot prompt type:

lla dmx_usb=open

I want to help out, what can I do?

I'm always after people to help, there are a number of roles to fill both technical and non-technical. I'm particularly interested in hearing from people in the following areas:

How is the IP Address assigned?

The LLA Live CD will attempt to get an IP address from a DHCP server. If that fails, it will fall back to assigning an IP address as per the Art-Net specification (ie. 10.x.y.z where x.y.z are the last three bytes of the mac address)

How do I change the IP Address ?

Stop llad, configure the network interface and start it again:

root@tty[/]# /etc/init.d/llad-live stop Stopping LLA Daemon: llad. root@tty1[/]# ifconfig eth0 10.0.0.1 netmask 255.0.0.0 root@tty1[/]# /etc/init.d/llad-live start Starting LLA Daemon: llad. root@tty1[/]#

I want to be able to store my patch setups between reboots

Later versions will allow the config to be stored on a USB drive.

Where do I send bug reports ? / It doesn't work

Email webspam @ nomis52 . net . Note the examples of a good and bad bug report below (see also How to ask Questions )

Bad

To: webspam @ nomis52 . net
Subject: fix it

it doesnt work hlp me pls

Good

To: webspam @ nomis52 . net
Subject: lla fails to communicate with device Y

LLA doesn't work using protocol X talking to device Y. I've attached a capture and the output of ifconfig.
Also attached is the capture from device Y successfully communicating with device Z.  

How do I create a capture / What is a capture ?

A capture is a log of traffic on the network. They are invaluable for debugging network / protocol related issues. If you are having difficulty with one of the network protocols, the first thing I'll ask for is a capture. To create a capture do the following:

root@tty1[/]#tcpdump -i eth0 -s0 -w /tmp/capture

Leave it running for the test and when complete hit Control-C. Then email the capture file to me. The easiest way is to copy it onto a USB flash drive. After intserting the drive run:

root@tty1[/]# mount /mnt/sda1 root@tty1[/]# cp /tmp/capture /mnt/sda1 root@tty1[/]# umount /mnt/sda1

How do I see the LLA logs ?

You need to do two things: start the logging process and increase the log output of lla. To start the logger type:

root@tty1[/]# /etc/init.d/sysklogd start Starting system log daemon: syslogd.

Now we find the process ID of llad:

root@tty1[/]# ps aux | grep [l]lad simon 18523 0.0 0.2 3160 1424 pts/8 S+ 16:47 0:00 /usr/bin/llad

The pid is the second column above (18523). Your output will vary slightly. Now send llad a signal to increase the logging:

root@tty1[/]#kill -USR1 18523 root@tty1[/]#kill -USR1 18523 root@tty1[/]#kill -USR1 18523

Do this three times to change the log level from Emergency -> Critical -> Warning -> Info . Output is sent to /var/log/syslog .

I can't see any of the network plugins loaded (ArtNet, ESPNet, ShowNet etc)

It's possible your network device wasn't detected. Try an ifconfig from the console:

root@tty[/]# ifconfig eth0 Link encap:Ethernet HWaddr 00:11:2F:D6:3C:9D inet addr:10.168.11.9 Bcast:10.255.255.255 Mask:255.0.0.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1485481 errors:0 dropped:0 overruns:0 frame:0 TX packets:1303182 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:366773952 (349.7 MiB) TX bytes:127874369 (121.9 MiB) Interrupt:177 Memory:f7c00000-0 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:2843 errors:0 dropped:0 overruns:0 frame:0 TX packets:2843 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:859136 (839.0 KiB) TX bytes:859136 (839.0 KiB)

There should be one network device marked eth0, if there is only lo, then you're card wasn't detected.

How do I enable the Python libraries ?

Run configure with --enable-python-libs.

What about support for device X ?

Is there a plugin for DMX4Linux?

No, but it's planned. I'm waiting for a release of DMX4Linux that runs on 2.6

Can LLA make recordings of my show and play them back at a later stage ?

Yes, this functionality exists, but it hasn't been rolled into the main release yet.

What about MIDI support

Coming soon... :)

And ACN support ?

Well as soon as ESTA standardises it.....