This article discusses the procedure for setting up a configuration for a cell with multiple robots. Creating and editing a configuration for a multi-robot cell is the same procedure as for a single-robot cell, except that a tooling mounting would need to be added for each robot.
The following procedure assumes that a cell is already created and multiple robots are already loaded in it.
Create a configuration
Open the cell in the cell editor.
In the Cell tree, select the cell.
In the Cell Settings pane on the right, next to Configuration repository, select the
button to add a new configuration. 
Select the Edit button to edit configuration options.
For the first robot, set Tooling mounting options.
Tooling mounting frame: Select the tooling mounting frame for that specific robot.
Default tooling: Select the default tooling for the robot. Note that the same tooling cannot be used by different robots.
Default user frame: Optional. You can apply a default user frame to a given robot.
Select Add tooling mounting.
Set Tooling mounting options for the second robot.
Repeat steps 6 and 7 for any additional robots.
Set a Path mounting frame and Default home position, as you would for a single-robot configuration. Also set other common options, as needed.
When you are finished making changes to the configuration, click OK.
You can create more than one configuration for a multi-robot cell. For example, you could create one configuration with only one robot active and the other robots idle. Then, you could create a second configuration with all robots active. When programming a part, you could then easily select the cell configuration needed.