Delta MH300 Series User Manual

Chapter 17 Safe Torque Off FunctionMH300
17-5
17-4 Failure Rate of the Drive Safety Function
The relevant safe loop parameters are shown as Table 17-3.
Item Definition Standard Performance
SFF Safe failure fraction IEC61508
S1–DCM = 88.35%
S2–DCM = 88.2%
HFT (Type A
subsystem)
Hardware fault tolerance IEC61508 1
SIL Safety integrity level
IEC61508 SIL 2
IEC62061 SILCL 2
PFH
Average frequency of dangerous
failure [h-1]
IEC61508
1.36 x 10
-9
PFD
av
Probability of dangerous failure on
demand
IEC61508
5.99 x 10
-6
PTI Proof test interval IEC61508 1 year
Category Category ISO13849-1 Category 3
PL Performance level ISO13849-1 d
MTTF
d
Mean time to dangerous failure
ISO13849-1 High
DC Diagnostic coverage ISO13849-1 Low
Table 17-3 Relevant safe loop parameters
17-5 Reset the Parameter Settings
Use Pr.06-44 to specify the reset method when an STO alarm occurs.

06-44
STO Latch Selection
Default: 0
Settings
0: STO Latch
1: STO no Latch
 Pr.06-44 = 0: STO Alarm Latch. After you clear the cause of the STO Alarm, use a Reset command
to clear the STO Alarm.
 Pr.06-44 = 1: STO Alarm no Latch. After you clear the cause of the STO Alarm, the STO Alarm
clears automatically.
 All of the STL1–STL3 errors are “Alarm Latch” mode (in STL1–STL3 mode, the Pr.06-44 function
is not effective).

Delta MH300 Series Specifications

General

Brand	Delta
Model	MH300 Series
Category	DC Drives
Language	English