GCPro issue: many devices, same MIDI channel

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
Post Reply
scoesh
Posts: 6
Joined: Sat Jun 20, 2009 9:19 pm

GCPro issue: many devices, same MIDI channel

Post by scoesh » Sat Jun 20, 2009 9:28 pm

Whenever I attempt to assign more than one device to the same MIDI channel on the GCPro, I get transmission drop outs. The effect unit I am trying to control just doesn't respond.

Is this an issue with the effect unit or the GCPro?
Thanks.

alfonso
Posts: 27
Joined: Wed Jun 10, 2009 2:03 am

Re: GCPro issue: many devices, same MIDI channel

Post by alfonso » Sun Jun 21, 2009 12:13 am

You cannot send, say, different values for the same data in the same channel. You cannot send, for example two different prg.changes in the same channel or 2 values of the same CC....MIDI messages are coming out from the same port and the different channels have sense because you can connect several devices at the same port and have independent data.

What you could do is to program just one device prg. changes for a single MIDI channel, then you can map in the receiving devices how will they respond to that message. It's like the GCP says "Go to Program 22" and each receiving device maps that order to the preset they have in that location or the one you have decided for them in case that alternative mapping is available. You have both devices MIDI connected but they are treated as a single device from the GCP.

That's how MIDI works.

scoesh
Posts: 6
Joined: Sat Jun 20, 2009 9:19 pm

Re: GCPro issue: many devices, same MIDI channel

Post by scoesh » Sun Jun 21, 2009 10:16 am

Can I control my CAE 4x4 audio loops (CC#11-19) with any of the 200 GCpro Presets or are they solely controllable through the instant access buttons?

Josh Fiden
Site Admin
Posts: 177
Joined: Tue Mar 10, 2009 11:36 pm

Re: GCPro issue: many devices, same MIDI channel

Post by Josh Fiden » Sun Jun 21, 2009 12:23 pm

scoesh wrote:Whenever I attempt to assign more than one device to the same MIDI channel on the GCPro, I get transmission drop outs. The effect unit I am trying to control just doesn't respond.

Is this an issue with the effect unit or the GCPro?
Thanks.
The effect unit and the Ground Control Pro are fine. There's an issue with the operator....

On the GCP, you must assign each device to a different channel. Then each target device must be set to respond to that channel.

Setting more than one device to the the same MIDI channel on the GCP is an error. The channel is how a MIDI message is targeted to a specific device. If the GCP has multiple devices set to the same channel, it will send out more than one command to the same device. Since the messages go out about 1 mS apart (1/1000th of a second, fairly fast), many devices will get confused and not respond properly.

If you have more questions, please post them.

Josh Fiden
Founder / CEO

Josh Fiden
Site Admin
Posts: 177
Joined: Tue Mar 10, 2009 11:36 pm

Re: GCPro issue: many devices, same MIDI channel

Post by Josh Fiden » Sun Jun 21, 2009 12:37 pm

scoesh wrote:Can I control my CAE 4x4 audio loops (CC#11-19) with any of the 200 GCpro Presets or are they solely controllable through the instant access buttons?
First, verify which controller numbers your 4x4 responds to, 11-19 would be 9 loops/switches and there are only 8. Those don't look like the standard cc#s.

Set the GCP instant access buttons to the channel and cc# for each 4x4 loop/switch. As you set each one, press cursor right and select "transmit with preset". Now when you create presets, they will also set the state of the 4x4. You can also access the loops/switches directly with the IA buttons.

Josh Fiden
Founder / CEO

Post Reply