The C1 connector includes the power supply (24VDC required) and the safety inputs STO STO-A and-B.
STO Input are TUEV certified with specific firmware.

VERY IMPORTANT NOTE Inputs for redundant management Safe Torque Off The circuit is in the stage of approval; at the moment the manufacturer cannot be held responsible for any use for security functions . The servo amplifier cannot be enabled if these inputs are leaved disconnected, in this case the motor will remain without torque and if it is rotating, it will stop for inertia. Is mandatory to drive the STO inputs only when the servo amplifier is disabled

If you do not intend to use the safe inputs STO-A and STO-A just connect them directly to connector 1 of C1 (see diagram below).