Banner EZ-SCREEN­ Safety Light Curtain Systems - Manual (Page 68)

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P/N 133487
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Overview
66
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
EZ-SCREEN
Instruction Manual
Glossary
Fixed Blanking: A programming feature that allows a safety light
screen system to ignore objects (such as brackets or fixtures)
which will always be present at a specific location within the
defined area. The presence of these objects will not cause the
system’s safety outputs (e.g., Final Switching Devices) to trip or
latch. If any fixed objects are moved within or removed from the
defined area, a Lockout condition results.
Floating Blanking: See Reduced Resolution.
FMEA (Failure Mode and Effects Analysis): A testing
procedure by which potential failure modes in a system are
analyzed to determine their results or effects on the system.
Component failure modes that produce either no effect or a
Lockout condition are permitted; failures which cause an unsafe
condition (a failure to danger) are not. Banner safety products
are extensively FMEA tested.
Guarded Machine: The machine whose point of operation is
guarded by the safety system.
Hard Guard: Screens, bars, or other mechanical barriers
affixed to the frame of the machine intended to prevent entry
by personnel into the hazardous area(s) of a machine, while
allowing the point of operation to be viewed. The maximum size
of openings is determined by the applicable standard, such as
Table O-10 of OSHA 29CFR1910.217, also called a “fixed barrier
guard.”
Hazardous Area: An area that poses an immediate or impending
physical hazard.
Hazard Point: The closest reachable point of the hazardous
area.
Internal Lockout: A Lockout condition that is due to an internal
safety system problem. Generally, indicated by the red Status
indicator LED (only) flashing. Requires the attention of a
Qualified Person.
Key Reset (Manual Reset): A key-operated switch used to reset
a safety light screen system to RUN mode following a Lockout
condition, or to enable machine operation following a Latch
condition. Also refers to the act of using the switch.
Latch Condition: The response of the safety light screen Safety
Outputs (e.g., OSSDs) when an object equal to or greater than
the diameter of the specified test piece enters the defined area.
In a Latch condition, safety outputs simultaneously de-energize
and open their contacts. The contacts are held (latched) open
until the object is removed from the defined area and a manual
reset is performed. A latching output is used most often in
perimeter guarding applications. (See Trip Condition.)
Lockout Condition: A safety light screen condition that is
automatically attained in response to certain failure signals (an
internal lockout). When a Lockout condition occurs, the safety
light screen’s safety outputs turn OFF; the failure must be
corrected and a manual reset is required to return the system to
RUN mode.
Machine Primary Control Element (MPCE): An electrically
powered element, external to the safety system, which directly
controls the machine’s normal operating motion in such a way
that the element is last (in time) to operate when machine
motion is either initiated or arrested.
Machine Response Time: The time between the activation of
a machine stopping device and the instant when the dangerous
parts of the machine reach a safe state (are brought to rest).
Minimum Object Sensitivity (MOS): The minimum-diameter
object that a safety light screen system can reliably detect.
Objects of this diameter or greater will be detected anywhere in
the defined area. A smaller object can pass undetected through
the light if it passes exactly midway between two adjacent light
beams. Also known as MODS (Minimum Object Detection Size).
See also Specified Test Piece.
Muting: The automatic suspension of the safeguarding function
of a safety device during a non-hazardous portion of the
machine cycle.
OFF State: The state in which the output circuit is interrupted
and does not permit the flow of current.
ON State: The state in which the output circuit is complete and
permits the flow of current.
OSHA (Occupational Safety and Health Administration): A
U.S. Federal agency, Division of the U.S. Department of Labor,
that is responsible for the regulation of workplace safety.
OSSD: Output Signal Switching Device. The safety outputs that
are used to initiate a stop signal.
Part-Revolution Clutch: A type of clutch that may be engaged
or disengaged during the machine cycle. Part-revolution
clutched machines use a clutch/brake mechanism, which can
arrest machine motion at any point in the stroke or cycle.
Pass-Through Hazard: A situation that may exist when
personnel pass through a safeguard (at which point the hazard
stops or is removed), and then continue into the guarded area.
At this point the safeguard may not be able to prevent an
unexpected start or restart of the machine with personnel within
the guarded area.
Point of Operation: The location of a machine where material
or a workpiece is positioned and a machine function is
performed upon it.