A group is a collection of two or more motors that monitor each other's faults and stop if something is wrong.
Each motor in a group provides feedback that allows Spikemark to know if another motor in its group has experienced an issue so it can stop itself.
Grouped motion is not synchronized motion - it is possible to send motors to different targets positions in the same cue.
This is a nifty feature. Imagine a scenario where you have two motors picking a single truss and you want to make the truss tip up and down. You would want both motors to stop if it went outside its position path, but you still want to have different target positions
Each Stagehand in a group creates an additional connection to Spikemark. This connection is used solely for the purpose of communicating group status’ and operates faster than the regular network connection. When jogging a group, running Move to Position, or running a cue, each Stagehand in the group will monitor this network connection and if it doesn’t receive an “OK” status message every 100ms it will abort motion to all the Motors in the group.