Delta VFD-ED Series User Manual

Chapter 16 Safe Torque Off Function | VFD-ED
16-3
16-2 Description of STO’s Functions
The STO (Safe Torque Off) function is to cut off the motor’s power supply to prevent the motor from
producing torque force. The STO function is run by two independent hardware circuits to control the
drive signals emitted by the motor’s current, and then to cut off motor drive’s power module output in
order to safely stop the motor drive.
The following table describes the terminal functions.
Signal Channel Status of Photo Coupler
STO
Signal
STO1
–SCM1
ON (High) ON (High) OFF (Low) OFF (Low)
STO2–SCM2
ON (High) OFF (Low) ON (High) OFF (Low)
Drive Output Status Ready
STL2 mode
(Torque output off)
STL1 mode
(Torque output off)
STO mode
(Torque output Off)
Table 16-2
 STO is Safe Torque Off
 STL1–STL3 means an STO internal hardware error.
 STL3 means STO1–SCM1 and STO2–SCM2 has an internal circuit error.
 STO1–SCM1 ON (High): means STO1–SCM1 has connection to a +24 V
DC
power supply.
 STO2–SCM2 ON (High): means STO2–SCM2 has connection to a +24 V
DC
power supply.
 STO1–SCM1 OFF (Low): means STO1–SCM1 has no connection to a +24 V
DC
power
supply.
 STO2–SCM2 OFF (Low): means STO2–SCM2 has no connection to a +24 V
DC
power
supply.

Delta VFD-ED Series Specifications

General

Brand	Delta
Model	VFD-ED Series
Category	DC Drives
Language	English