Safety Stop (Sto) Test; Specifications; Function Block Diagram - Fuji Electric Alpha7 VV User Manual

CHAPTER 2 WIRING
 Employ double [EN1+] and [EN2+] inputs (with redundancy circuit) to ensure that the safety stop
function (STO) is not lost due to a single fault.
If a single fault is detected by the safety cutoff circuit, an alarm is output to external devices, and
the servo amplifier slowly stops the motor (free-run stop), even if the [EN1+] and [EN2+] status is
ON. (The alarm output function does not guarantee that an alarm will be output for all single faults,
2
however, compatibility with EN ISO13849-1 PL=e Cat. 3 is possible.)
 The safety stop function (STO) is not designed to completely cut off the power supply and motor
electrically. Cut off the servo amplifier input power supply completely, and begin wiring and
maintenance work after 5 minutes or longer have elapsed.
 A motor rotation equivalent to electrical angle of 180° may occur following a servo amplifier fault.
Employ designs that present no danger based on load conditions.
2.7.2.3

Safety Stop (STO) Test

Conduct a check once a day to ensure that the safety stop function (STO) is functioning normally.

2.7.3 Specifications

2.7.3.1

Function Block Diagram

2-112
Safety Function
Servo amplifier
L1
L2
Power
supply
L3
24 V power
Safety
supply
switch
EN1+
EN1-
EN2+
EN2-
0V
Fig. 2.7.3-1 Function block diagram
U
V
Motor
W
Drive circuit