Yes! It would be incredibly useless if they couldn't.
What am i doing wrong?
I wish I knew! Mine worked exactly correctly the very first time I connected it.
Likely one or both of the pedals is connected backwards, try reversing the In and Out connections on the Ernie Ball pedal. If that does not work try getting each pedal working when it is the only pedal connected, then test with both connected. Also you are not saying if you have configured the pedal within the Ground Control Pro preset for what CC# it is to transmit and what target device it is to send this message to.
I am in the process of doing exactly what you are doing with your expression pedals. I have a G Major 2 and I am wanting to use an Ernie Ball pedal (on order) to control whammy and crybaby effects on the G-major 2 and get a Mission TT switch for the delay tap tempo on the G Major 2 and my Line 6 echo pro. I am also wanting to connect both of these to my GCP (which is also connected to the GCX audio switcher).
Did you manage to overcome your initial difficulties? I'd love to find out so that I can possible order one of these mission latching pedals.
I am sorry its taken so long to reply. My rig has been in storage the last few months. You've probably got this sorted by now but i will explain my solution anyway for anyone else that might need a read.
It is possible as JohnClark says to do all these things. I was doing a few things wrong!
My solution ;
I have connected my Ernie Ball expression pedal to pedal 1 on GCP and set cc# to 10
I have connected my Mission TT to pedal 2 on GCP and set cc# to 20
On G major Setup>Mod>Tap Tempo Set this to cc#20
In Global I have Tap Master set to preset.
Pedal 2 and Tap Tempo
Make sure to set GCP to the same cc# as the G major 2 as above.
To use Tap Tempo make sure to turn OFF all modifier ie M1 M2 M3 M4 in said preset. (this was my mistake)
In the preset settings set the Tempo 1/4 or 1/8 etc NOT ignored.
I have this working on Delay, Trem, Univibe, Panner etc. It works great.
I use the Mission TT to set all tempos.
Pedal 1
A bit different to the above you will need to make sure the cc# is the same on both units but with this pedal for whammy, Univibe speed select etc you will need to use the modifier functions and set the response curve in % terms.
Hope this helps anyone who has had the same problems as i did.
