Abbreviations - ABB ACS580-04 Hardware Manual

146 Safe torque off function

Abbreviations


Abbr. Reference
Cat. EN ISO 13849-1
CCF EN/ISO 13849-1
DC EN/ISO 13849-1
FIT IEC 61508
HFT IEC 61508
MTTF EN/ISO 13849-1
D
PFD IEC 61508
avg
PFH IEC 61508
PL EN/ISO 13849-1
SC IEC 61508
SFF IEC 61508
SIL IEC 61508
SILCL EN 62061
SS1 EN 61800-5-2
STO EN 61800-5-2
T1 IEC 61508
Description
Classification of the safety-related parts of a control system in respect
of their resistance to faults and their subsequent behavior in the fault
condition, and which is achieved by the structural arrangement of the
parts, fault detection and/or by their reliability. The categories are: B, 1,
2, 3 and 4.
Common cause failure (%)
Diagnostic coverage
Failure in time: 1E-9 hours
Hardware fault tolerance
Mean time to dangerous failure: (The total number of life units) / (the
number of dangerous, undetected failures) during a particular
measurement interval under stated conditions
Average probability of dangerous failure on demand
Average frequency of dangerous failures per hour
Performance level. Levels a...e correspond to SIL
Systematic capability
Safe failure fraction (%)
Safety integrity level (1...3)
Maximum SIL (level 1...3) that can be claimed for a safety function or
subsystem
Safe stop 1
Safe torque off
Proof test interval