Inovance SV660F Series Safety Function Guide

STO
‑75‑
6 STO
6.1 Overview
Figure 6‑1 Schematics of the STO function
Safe Torque Off (STO) is a safety function that complies with IEC 61800‑5‑2:2016. It is
built into Inovance SV660F series servo drives.
The STO function inhibits the control signal of the power semiconductors on the drive
output end, preventing the drive from generating torque at the motor shaft end.
The STO function prevents movement of the motor by two redundant external
hardware signals (STO1 and STO2) that block the PWM signals from being outputted
to the power layer of the servo drive. STO1 and STO2 input signals must be both
active to allow the servo drive to operate normally.
See the following table for the STO function.
STO1 input STO2 input PWM signal
H H
Normal
L H
Inhibited
H L
Inhibited
L L
Inhibited
STO (safe torque)
Description
Cuts off the power of the motor.
Description
The safe torque off (STO) function brings the machine safely into a no‑
torque state and prevents it from unexpected start. If the motor is
running when STO function is activated, it coasts to stop.
Safe state
Disables the PWM gating signal of the drive.
Operating mode High demand mode or continuous mode
6.2 Function Use and Monitoring
Function Use
The keypad displays the STO function state and error information.
See the following table to identify the cause of a fault and the action to be taken.
Contact Inovance technical support if the fault persists after corrective actions listed
in the following table are taken.
Fault codes related to the STO function are listed in the following table:

Inovance SV660F Series Specifications

General

Brand	Inovance
Model	SV660F Series
Category	Servo Drives
Language	English