Safe Torque Off Terminal Function Description - Delta C2000 Plus Series User Manual

17-2 Safety Torque Off Terminal Function Description
The Safe Torque Off function (STO) is to cut off the power supply to motor through the hardware,
thereby the motor could not produce torque.
The STO function controls the motor current driving signal through two hardware circuits
respectively and thus cut off the inverter power module output in order to achieve the status of safety
stop.
Operation principle Description as following table 1:
Table 1: Terminal operation description
Signal Channel
STO1–SCM1
STO signal
STO2–SCM2
Driver Output status
 STO means Safe Torque Off
 STL1–STL3 means Safe Torque Off hardware abnormal.
 STL3 means STO1–SCM1 and STO2–SCM2 internal circuit detected abnormal.
 STO1–SCM1 ON (High): means STO1–SCM1 has connection to a +24 V
 STO2–SCM2 ON (High): means STO2–SCM2 has connection to a +24 V
 STO1–SCM1 OFF (Low): means STO1–SCM1hasn't connection to a +24 V
 STO2–SCM2 OFF (Low): means STO2–SCM2hasn't connection to a +24 V
ON (High) ON (High)
ON (High) OFF (Low)
STL2 mode
Ready
(Torque output off)
17-3
Chapter 17 Safe Torque Off Function | C2000 Plus
Photo-coupler Status
OFF (Low)
ON (Low)
STL1 mode
(Torque output off)
DC
DC
OFF (Low)
OFF (Low)
STO mode
(Torque output off)
power supply.
power supply.
power supply.
DC
power supply.
DC