Hi, as I met the same problem I would like to give you the solution.
NUM_FOB = 2
PORT_FOB = 0
BAUD_FOB = 115200
flock1 = viz.add('flockofbirds.dls')
flock2 = viz.add('flockofbirds.dls')
This is the way you can connect 2 FOB together.
After these few lines, you can link your viewpoint, objects or other stuff to the sensors.
Best Regards