Light desks · betagrandMA3 and onPC

The tempo on a speed master over OSC.

Beta

Built from the grandMA3 manual (OSC /cmd, Master 3.1 At BPM) and tested against a simulation. Not yet confirmed on a real grandMA3 or onPC.

How it works

The grandMA3 takes command line commands over OSC (address /cmd, text). LJ Link sends the command for the speed master there.

1. OSC input on the desk

Menu → In & Out → tab OSC.
At Interface choose the network port through which the LJ Link computer is reachable.
Add a line (or use one) with these values:
Field Value
Mode UDP
Port 8000 or another free port, the same in LJ Link
Prefix empty
Receive Command Yes (otherwise commands are ignored)
EchoInput Yes for testing: incoming messages show in the System Monitor
Switch on Enable Input. When OSC arrives, its title bar lights yellow.

Field	Value
Mode	`UDP`
Port	8000 or another free port, the same in LJ Link
Prefix	empty
Receive Command	Yes (otherwise commands are ignored)
EchoInput	Yes for testing: incoming messages show in the System Monitor

Info

With a prefix such as gma3 the desk expects /gma3/cmd. LJ Link sends to /cmd, so leave the prefix empty.

2. Speed master

Assign the effect or sequence to a speed master (the first is Master 3.1).
Test on the command line: Master 3.1 At BPM 120, Enter.

3. Set up in LJ Link

Light desk link → grandMA3 / grandMA3 onPC (OSC).
Address of the desk (onPC on this computer: 127.0.0.1). The search does not find a grandMA3 yet.
Port as on the desk, e.g. 8000. Command Master 3.1 At BPM {bpm}.
Save, Send test. With EchoInput the message shows in the System Monitor.

Problems

You see	Cause	Fix
Enable Input never lights	wrong port, wrong interface, firewall	same port? right interface? allow in the firewall
lights, but nothing happens	Receive Command `No` or a prefix	`Receive Command = Yes`, prefix empty
master changes, effect does not	effect on another master	assign the effect

Help us test

Tried it on your desk? Post the result in our Discord or report it: desk, software version, what worked and what did not. That is how beta and alpha become stable.

Something missing or wrong?

Ask in our Discord or report a problem. Reports from real gear help most, also when something does not work.