Roland GR-540 User Manual page 379

Connecting Two or More Instances of This
Machine to a Single Computer
(Connecting Multiple Units with a USB Cable)
When connecting multiple instances of this machine to a single computer with a USB cable, you must change
the USB number of each machine so that the computer can distinguish between output destinations. The
machine's default setting is "A." When connecting two or more machines, the second machine and every
machine thereafter must be configured with a setting other than "A" so that the machine can distinguish the
output destination of the data.