SMC Networks LECSN-T Series - 13.1.5 Specifications

13. USING STO FUNCTION
13 - 4
13.1.5 Specifications
(1) Specifications
Item
Specifications
Safety function
STO (IEC/EN 61800-5-2)
Safety performance
ISO/EN ISO 13849-1 category 3 PL e, IEC/EN 61508 SIL 3,
EN 62061 SIL CL3, EN 61800-5-2
Mean time to dangerous failure
(MTTFd)
MTTFd ≥ 100 [years] (Note)
Diagnostic converge (DC)
DC = Medium, 97.6[%] (Note)
Average probability of dangerous
failures per hour (PFH)
PFH = 6.4 × 10
-9
[1/h]
Number of on/off times of STO
1,000,000 times
CE marking
LVD: EN 61800-5-1
EMC: EN 61800-3
MD: EN ISO 13849-1, EN 61800-5-2, EN 62061
Note 1.
This is the value required by safety standards.
2.
The safety level is determined by the setting value of [Pr. PF18 STO diagnosis error detection time] and
whether or not STO input diagnosis by TOFB output is performed. For details, refer to the function
column of [Pr. PF18] described in section 5.2.6.
(2) Function block diagram (STO function)
Base power
supply for
upper arm
Base power
supply for
lower arm
Shut-off signal (STO1)
CN8
Monitor signal (TOFB1)
Shut-off signal (STO2)
Monitor signal (TOFB2)
Shut-
off
Shut-
off
Servo motor
M
Pow er
module
(3) Operation sequence (STO function)
STO2STO1
ON
OFF
ON
OFF
ON
OFF
ON
OFF
0 r/min
(8 ms)
Servo motor speed
EM2 (Forced stop 2)
Magnetic contactor
Base circuit
(Supplying energy to
the servo motor)