You can connect two machines together with copy connector. When you set up a copy job on one machine (the main machine), data is transferred to the other (the sub-machine) so that copies can be made on both machines simultaneously (Connect Copy).
You can complete large volume copy runs in shorter time.
Even if one machine runs out of paper, or stops because of a paper jam, the other machine can still continue to finish the job.
See "Connect Copying", Copy/ Document Server.