• drive-to-drive (D2D) communication implemented by application programming.See the firmware manual of the drive for the related parameter settings.Enable bus termination on the units at the ends of the drive-to-drive link. Disable bustermination on the intermediate units.Use shielded twisted-pair cable with a twisted pair for data and a wire or another pair forsignal ground (nominal impedance 100 to 165 ohm, for example Belden 9842) for the wiring.For best immunity, ABB recommends high quality cable. Keep the cable as short as possible.Avoid unnecessary loops and parallel runs near power cables such as motor cables.The following diagram shows the wiring between control units.ZCU-12XD2DXD2DXD2DJ3J3 J3123BABGND123BABGND123BABGNDZCU-14, BCU-x2XD2DXD2DXD2D1234BABGNDSHIELD1234BABGNDSHIELD1234BABGNDSHIELDTermination ON Termination ONTermination OFFSafe torque off (XSTO, XSTO OUT)See chapter The Safe torque off function (page 313).Note:The XSTO input only acts as a true Safe torque off input on the inverter control unit.De-energizing the IN1 and/or IN2 terminals of other units (supply, DC/DC converter, or brakeunit) will stop the unit but not constitute a true safety function.Control units of the drive 307