Safety Monitoring Functions; Safe Torque Off (Sto) - Mitsubishi Electric RV-FR Series Instruction Manual

4.5 Safety Monitoring Functions

This chapter provides the functional overview and configuration method of the safety monitoring function.

Safe torque off (STO)

4.5.1
(1) Overview
This function electrically shuts off the motor driving energy according to input signals from external devices.
It corresponds to stop category 0 of IEC60204-1.
(2) Operation sequence
(a) STO start conditions
<SS1 command or emergency stop>
To trigger the STO function, input the SS1 command or the emergency stop signal. Inputting the SS1
command or the emergency stop signal causes the robot to start decelerating and, after the robot stops
safely, the STO function starts. For details on the sequence, see chapter 4.5.3 .
(No external signal can directly start the STO function.)
<When an error occurs>
The STO function is triggered if:
The robot fails to stop within a deceleration monitoring period while SS1 is running.
・
The robot fails to stop within a deceleration monitoring period while SS2 is running
・
An internal error occurs which hinders the robot control
・
(b) Program operation state
Program operation suspends during the STO monitoring. To resume, it is necessary to cancel all the SS1
start conditions and then perform program start operation.
(c) Operation restrictions
Operation restrictions during SS1/STO monitoring are shown in following table.
Operation
Servo-on
Program operation start
JOG operation
Opening or closing hand
(3) Configuring monitoring conditions
There are no parameters concerning the STO function.
Table 4-5: Operation restrictions during SS1/STO monitoring
Available
✓
Unavailable Remarks
Performing the servo-on operation
✓
during the SS1/STO monitoring
causes error
prohibited during SS1/STO).
The ALWAYS program does not
✓
stop.
The ERROR
performed.
✓
For the TB operation only.
4 SAFETY MONITORING FUNCTIONS
H2270 (Servo-on
program is not
Safety Monitoring Functions 4-41