Sto (safe torque off) inputs – ElmoMC Gold Line Digital Servo Drives-Gold Guitar User Manual
Page 40
Gold Guitar Installation Guide
Installation
MAN-G-GUTIG (Ver. 1.005)
40
4.8. STO (Safe Torque Off) Inputs
Activation of Safe Torque Off causes the drive to stop providing power that can cause rotation
(or motion in the case of a linear motor) to the motor.
This function may be used to prevent unexpected motor rotation (of brushless DC motors)
without disconnecting the drive from the power supply.
The motor is active only as long as 5 V is provided to both STO1 and STO2. Whenever any input
voltage is no longer present, power is not provided to the motor and the motor shaft continues
to rotate to an uncontrolled stop.
The STO inputs are latched which means that the motor can be re-enabled by a software
command only.
In circumstances where external influences (for example, falling of suspended loads) are
present, additional measures such as mechanical brakes are necessary to prevent any hazard.
This function corresponds to an uncontrolled stop in accordance with Stop Category 0 of IEC
60204-1.
Note:
This function does not protect against electrical shock, and additional measures to
turn the power off are necessary.
The following table defines the behavior of the motor as a function of the state of the STO
inputs:
Signal – STO1
Signal – STO2
Function
Not Active
Not Active
Motor is disabled
Not Active
Active
Motor is disabled
Active
Not Active
Motor is disabled
Active
Active
Motor can be enabled
Table 10: Motor Behavior According to Safety Inputs
Note:
In the Gold Guitar, STO1 also latches a software disable condition.
Pin (J1) Signal
Function
12
STO1
Safety 1 input
11
STO2
Safety 2 input
10
STO_RET
STO return
Table 11: STO Inputs Pin Assignments