The control unit 53
Safe torque off (XSTO, XSTO OUT)
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 brake
unit) will stop the unit but not constitute a true safety function.
FSO-xx safety functions module connection (X12)
See the user manual of the FSO-xx module. Note that the FSO-xx safety functions module
is not in use in supply, DC/DC converter or brake units.
SDHC memory card slot
The BCU-x2 has an on-board data logger that collects real-time data from the power modules
to help fault tracing and analysis. The data is stored onto the SDHC memory card inserted
into the SD CARD slot and can be analyzed by ABB service personnel.