How to control several reactors with one control computer?

[Shilan]

Hi Harrison,

I have one control computer and three reactors. How can I control all 3 together with this single control computer and what modifications should I make to the script? M0 works, but I get error for M1,etc. Thank you in advance.

[harrison]

Hi Shilan,
Can you explain what error you get? Perhaps share the log in PuTTy?
It should be that if you connect all the reactors up to the control computer via USB, and power all the reactors on, then you can access them all in the UI.

Harrison

[Shilan]

Thanks. The error I get as soon as I connect USB to devices M0 >0:

Starting watchdog
2021-05-18 18:50:13.480556 Initialising devices
2021-05-18 18:50:13.507939 Failed Multiplexer Comms 1 times
2021-05-18 18:50:13.530573 Failed Multiplexer Comms 2 times
2021-05-18 18:50:13.553000 Failed Multiplexer Comms 3 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.577049 Failed Multiplexer Comms 4 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.601112 Failed Multiplexer Comms 5 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.825867 Failed Multiplexer Comms 6 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.849889 Failed Multiplexer Comms 7 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.873935 Failed Multiplexer Comms 8 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.897944 Failed Multiplexer Comms 9 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.921968 Failed Multiplexer Comms 10 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.945871 Failed Multiplexer Comms 11 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.969874 Failed Multiplexer Comms 12 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:13.993830 Failed Multiplexer Comms 13 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.018004 Failed Multiplexer Comms 14 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.042269 Failed Multiplexer Comms 15 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.066489 Failed Multiplexer Comms 16 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.090627 Failed Multiplexer Comms 17 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.114730 Failed Multiplexer Comms 18 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.138888 Failed Multiplexer Comms 19 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.162999 Failed Multiplexer Comms 20 times
Failed to recover multiplexer on device M0
2021-05-18 18:50:14.187357 Failed Multiplexer Comms 21 times
Failed to recover multiplexer on device M0
Failed to communicate to Multiplexer 10 times. Disabling hardware and software!
[2021-05-18 18:50:14 +0000] [2752] [INFO] Shutting down: Master
[2021-05-18 18:50:14 +0000] [2752] [INFO] Reason: App failed to load.

Thanks again

[harrison]

OK, I assume these devices are all individually powered on with the wall plug?

Can you try and see what happens if you connect one reactor to M0 and then a second to M2? Or M0 and M3? etc.

What if you connect different reactors to M0? Do only some of the reactors work (while others don’t)?

I want to diagnose whether there is a problem with the control computer (i.e. one of the plugs is broken on it), or if there is a problem with one of the individual reactors.

[Shilan]

Thanks for your quick reply!

Yes, they are individually powered on with the wall plug.
It seems only M0 works cause no other device work in any combination. I can use different reactors with M0.

[harrison]

Thanks Shilan,
So based on what you said it seems that the reactors are fine – since all of them work if plugged into M0. However, you are saying that all of the other ports (i.e. M1-M7) are not working for unclear reasons. Is my understanding correct?

If that is the case I would say the most likely cause is a problem with the soldering of the Multiplexer chip, which is one of the circuits on the Control PCB (i.e. the PCB that has the M0-M7 ports on it).

Labmaker should be able to replace it for you if that is the case. Send them an email describing the problem and link them to this thread. They should be able to fix a replacement, they have been very good at this in the past!

[Shilan]

Thank you. I will contact them.

Another question, and sorry if it doesn’t directly relate to topic here. But, my reactors frequently stop working and I will not know that has happened unless I go to the lab the next day. Then, I have to restart Putty and re-calibrate OD and switch on the pumps again. I was wondering if that is also related to my faulty PCB you mentioned?
Thanks

[harrison]

Potentialy yes. Though I am a little confused – if the control computer doesn’t work beyond one reactor at a time, how is it that you have multiple reactorS running such that they can stop working?

What does the PuTTY window say the next day when they stop working?

As to the cause: If the control computer is faulty then that is the most likely. Beyond that, the next most probable reason could be that you are getting liquid on the moisture sensing track at the top, which crashes the software. Are you running it in Turbidostat mode, or something else?

As an aside, if you are having any issues like this I would recommend updating to the V2.0 Software (see the Software page on this site) which makes it much more robust.

[Shilan]

Thanks Harrison,
I meant that I have the same issue regardless of which reactor I choose to run my culture. I use the device at the chemostat mode and it is very unlikely that I have had any overflow that has caused this problem and I have checked for it several times. When the reactor stops by itself, I see no PuTTY window open on the screen, but the GUI is open. Then, I re-connect to enable the OD reading, but the pumps sometimes work in that condition.
I’ll update to the latest version. But, do you think the whole control computer including the BeagleBone should be replaced or just its PCB?
Thanks

[harrison]

It should really only be the PCB.
You say you don’t see ANY putty window. That is very strange – if the device crashes it should not be possible for it to close the putty window. The window should stay open at all times, even if you unplugged the control computer from your PC (Though it would throw up an error message in Putty).

If Putty is literally gone, are you sure your PC isn’t restarting or crashing somehow? For example, is it a Windows computer restarting itself to install updates (which happens painfully often if you leave them running overnight!)

If the device itself is crashign then the putty window should remain open and give error messages.

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