7-31 Before Using the Products2 Preparation3 Connection4 Setup5 Adjustment6 When in Trouble7 SupplementSafety input/output signalCautionFor list of connector pin numbers, refer to P.2-22,Signal Symbol Pin No. Contents ControlmodeSafetyinput 1SF1+ 4 • Input 1 that triggers STO function. This input turnsoff the upper arm drive signal of power transistor.• When using the function, connect this pin in a wayso that the photocoupler of this input circuit turns offto activate STO function. Compatibleall controlmodeSF1− 3Safetyinput 2SF2+ 6 • Input 2 that triggers STO function. This input turnsoff the lower arm drive signal of power transistor.• When using the function, connect this pin in a wayso that the photocoupler of this input circuit turns offto activate STO function.SF2− 5Safety input 1 or 2 enables STO to operate within 5 ms, causing motor output torque toturn off.• Safety equipment self-diagnosis L pulseSafety output signal from the safety controller and safety sensor may include L pulse forself-diagnosis.To prevent the L pulse from mis-triggering STO function, the safety input circuit hasbuilt-in filter that removes the self-diagnosis L pulse.Therefore, if the off period of safety input signal less than 1 ms, the safety input circuitdoes not detect this “off” event.To validate this “off” period, turn off the input signal for more than 5 ms.Safety inputsignalServo driverOperateL pulse for self-diagnosis1 ms or shorter 5 ms or shorter5 ms or moreSTO state7 1. Safety functionSupplement Input & output signals