Terminology - Mitsubishi Electric Melsec-QS Series Safety Application Manual

TERMINOLOGY

Term
Safety component
-related
Safety system
Safety functions
Safety measure
Category
SIL
Risk
Risk assessment
Link ID
Target failure measure
NC
NO
Close contact
Open contact
Dark test
A
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Equipment such as the safety compatible sensor and actuator.
System executing a safety functions to be required.
Functions to be realized for protecting a human from machinery hazards.
Measure for reducing the risk.
Safety level standardized in EN954-1. The safety level is classified into 5 levels of B and 1 to 4.
Safety level which is standardized in IEC61508. The safety level is classified into 4 levels of SIL1
to SIL4.
Degree of hazards, which is the combination of the occurrence probability and degree of an injury
and a health problem.
To clarify hazards in machinery and assess the degree of the hazards.
Unique network identifier which is given to each network of the CC-Link Safety system.
Target value of reliability for each SIL level standardized in IEC61508. There are PFD and PFH
depending on the operation frequency of the safety functions.
Abbreviation for normal close contact which is normally closed, but opened when a switch or other
function is operated.
Abbreviation for normal open contact which is normally opened, but closed when a switch or other
function is operated.
Same as NC.
Same as NO.
Outputs a pulse to turn OFF the input/output when it is ON, and performs the failure diagnostics to
contacts including external equipment.
Description