WEG SCA06 User Manual page 22

Commissioning
NOTE!
Simultaneously activation of the STO inputs means that the time between
the activation or deactivation of the inputs must be less than 1 s. This
time is also known as discrepancy time. If the time is longer than 1 s,
a fault code "F0160" will be shown on the display of the product. To
reset the fault code, it is necessary to set the STO switches to the same
state and then turn off the 24 Vdc power supply of the servodrive and
turn it on again.
NOTE!
Test pulses present at OSSD outputs are tolerated and do not trigger
the STO function since they do not last more than 1 ms.
22 | SCA06