Copperlan keeps crashing

Re: Copperlan keeps crashing

Postby Grouphome » 13 Apr 2017, 20:40

Ok strange stuff, Came back today. Started the system.
Opened up the manager.
Some extra links have been added. Even midi channels that arent being used.
Whats going on here?
Also one of the AL88 works from the beginning. Then all of the sudden it drops out and even with power turned off for about a minute it wont come back online.
Posts: 13
Joined: 15 Nov 2016, 15:10

Re: Copperlan keeps crashing

Postby CopperPhil » 13 Apr 2017, 21:11

Well, it is possible to have have one MIDI port channel connected to one or more destination port channel in CopperLan, this is splitting the MIDI stream. You can also merge several MIDI streams by connecting a set of MIDI source to a single MIDI destination.

In you case, you rely on the AL-88 to restore the connections. So at startup, each AL88 restore its destination and try to find them on the network. But note that as far I remember, if a destination is not reachable for about 1 min, then it is dropped. So, if you did not save the current setup for one of your AL88, and if this AL88 has a destination that was not reachable for 1 min at some point, the AL88 will try to reconnect to this destination during next startup. This could explain why you just had 1 connection, and then get 2 connections after the next power on.

So I have an obvious question but I must ask: are you sure that you saved the current config in all the AL88 when you finished the patching?

About your last sentence, 2 things:
- what about the MIDI traffic when the AL88 drops out? are you sending heavy sysex? a lot of clocks? fast MIDI sequence? Are you sure that you don't have MIDI loop as suggested by CopperHead in a message above?
- When you say that the AL88 wont come back after a restart, do you mean that you don't see it any more in the CopperLan Manager's Overview tab? Can you get it back if you restart all the AL88? or if you stop all MIDI traffic?
Posts: 480
Joined: 30 Mar 2011, 15:02
Location: Brussels

Re: Copperlan keeps crashing

Postby Grouphome » 13 Apr 2017, 22:47

Hello Phill,

The thing is.
The 5 interfaces turn on at the same time. So there is change in that.
For instance. If I have input one on AL88 1. Midi channel 4. Sent to AL88 3 port 4 midi channel 4 (My microQ).
The next day it was that setting. Plus it sends the midi channel to AL88 4 Port 3 midi channel 5 (which is my JX8P and not even the MIDI channel that it responds to. I have it set to Midi channel 9).

It's strange, I can work with it. But I find it strange that those connections happen.
I know I've saved the settings on all the interfaces. (through the copperlan manager).

The strange thing with the 5th AL88 is this.
It boots up with the other interfaces.
Midi data gets sent to it (note on off to port 1).
Then I turned on midi clock from my mpc (it sends the midi clock to al the AL88's to several ports (12 destinations in total, one to port 1 of the 5th AL88)).
I don't do anything else.
I was just working on a word document on a computer not connected to the network.
The I see the midi data stream dropping out. It is simple midi clock. Which all the other interfaces keep receiving without interruption.
I also see the copperlan led turning off.
Then after a minute it loses connection.
I try rebooting the 5th (power in out). And it boots with port 8 in and out leds on (nothing is connected to those ports). And no copperlan link.
Tried this a few times.
The only time it will come back in the system is after I turned everything off and restart it 10 minutes later.
I checked it the second time with My laptop on the copperlan network (wired). Used the copperlan manager to see what happens. (no vmidi connections or other things going to the computer). and as soon as the 5th AL88 starts acting strange, it dissapears from the manager and won't come back.
There is no midi loop. Cause I only have the midi outs connected of that AL88.
What can be wrong?
Could it be a hardware problem?

Thanks for the advice
Posts: 13
Joined: 15 Nov 2016, 15:10

Re: Copperlan keeps crashing

Postby CopperPhil » 14 Apr 2017, 09:30

Many thanks for this feedback, very interesting!

It seems to confirm what I thought. The global system is going down due to some MIDI traffic, in this case it look like it's due to the clocks.

The MIDI clock is generated by the MPC, do you mean the Akai MPC through a AL88 MIDI IN port? You send it to 12 destination: one to port 1 of each AL88, but what are the other destinations? What is the clock rate?

Important: do you also sent MTC alongside the MIDI clock?

Some explanation: in CopperLan, MIDI Clock is transferred as a real-time message, with very low latency and with disabled delivery confirmation sub-system. On the other hand, MTC is a MIDI sysex message, and this kind of message (Sysex) is transmitted through the CopperLan network using fully synchronized data transfer packets, definitely not designed to be used in real-time. What you describe makes me thinking of an overload of this data transfer handshaking subsystem, causing at some point data queuing (just because the sending AL88 must wait for the each receiving AL88 before sending the Sysex to the next one), and finally memory crash if the sending AL88 is not able to send the sysex to all destinations before receiving the next one.

-> So, if you are using MIDI MTC, please disable it just to check in a first time that this is the cause of the problem. Then, use it only where needed (not sure that all your destinations need MTC), and finally try to reduce the amount of MTC per second.

Again, there would be not problem with the MIDI Clock because we put a lot of care to make this working really well, with very low latency. But Sysex is a particular type of message that should never have been used in real-time situation.
Posts: 480
Joined: 30 Mar 2011, 15:02
Location: Brussels

Re: Copperlan keeps crashing

Postby Grouphome » 14 Apr 2017, 18:06

Hi Phill,

I haven't used MTC.
It's definitely turned off.

Posts: 13
Joined: 15 Nov 2016, 15:10


Return to Bug report