Banner EZ-SCREEN­ Safety Light Curtain Systems - Manual (Page 55)

P/N 68413 rev. A
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Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
EZ-SCREEN Point
Instruction Manual
Glossary of Terms
ANSI (Amer i can Na tion al Stan dards In sti tute): An as so ci a tion
of in dus try rep re sen ta tives which develops tech ni cal stan dards,
in cluding safety stan dards. These standards represent a con sen-
sus from a variety of in dus tries on good practice and design. ANSI
standards rel e vant to application of the EZ-SCREEN System
in clude ANSI B11.1 (me chan i cal pow er press es), ANSI B11.2
(hy drau lic power presses), and ANSI/RIA R15.06 (in dus tri al robots
and robot systems).
Blocked condition: A condition of the EZ-SCREEN Point System
when an opaque object of sufficient size blocks/interrupts the light
beam. When a Blocked condition occurs, OSSD1 and OSSD2
outputs simultaneously turn off within the System response time.
Control reliability: A method of en sur ing the performance integrity
of a con trol system . Control circuits are designed and con struct ed
so that a single failure or fault within the System does not prevent
the normal stopping action from being applied to the machine
when required, or does not create unintended machine ac tion,
but does prevent initiation of suc ces sive ma chine action until the
failure is corrected .
Designated Person: A person or persons identified and des ig nat-
ed in writing, by the employer, as being appropriately trained and
qual i fied to perform a specified check out procedure .
Diverse redundancy: A design feature in which two components
of different design, running from two different instruction
sets (if programmed components), constantly check all system
components, including each other.
Emitter: The light-emitting component of the EZ-SCREEN Point
System, con sist ing of synchronized mod u lat ed infrared LED.
Final Switching Device (FSD): The component of the machine’s
safety-related control system that interrupts the circuit to the
machine primary control element (MPCE) when the output
signal switching device (OSSD) goes to the OFF-state.
FMEA (Failure Mode and Effects Analysis): A testing pro ce-
dure 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 con di tion
are permitted; failures which cause an unsafe con di tion (a failure
to danger) are not. Banner EZ-SCREEN Sys tems are ex ten sive ly
FMEA tested.
Glossary of Safety Terms
Terms shown in italics in the definitions below are themselves defined elsewhere in the glossary.
Forced-guided con tacts: Relay con tacts that are me chan i cal ly
linked together, so that when the relay coil is energized or de-
energized, all of the linked contacts move together. If one set of
contacts in the relay becomes im mo bi lized, no other contact of
the same relay will be able to move. The function of forced-guided
contacts is to enable the safety circuit to check the status of the
relay. Forced-guided con tacts are also known as “positive-guided
contacts,” “captive con tacts,” “locked contacts,” or “safety relays.”
Full-revolution devices: A type of machine drive arranged such
that, once started, the machine can only be stopped when the full
cycle is complete. Examples include positive key clutches and
similar mech a nisms. Banner EZ-SCREEN Systems may not be
used with full-revolution devices.
Hard guarding: Screens, bars, or other mechanical barriers that
prevent a person from entering or remaining in the hazard area
undetected .
Internal lockout: A lockout condition that occurs due to an internal
EZ-SCREEN System problem. Indicated by the red Status indicator
(only) flashing. Requires the attention of a Qualified Per son.
Latch condition: The response of the OSSD outputs (they turn
OFF) when an object blocks/interrupts the light beam of the
EZ-SCREEN Point system, when operating in Latch Output
mode . A manual reset must be performed after all objects are
removed (the beam is clear) to reset the output latch and allow the
outputs to turn ON.
Lockout condition: A condition of the EZ-SCREEN Point System
that is automatically attained when the System detects internal
or certain external errors. A lockout condition causes all of the
EZ-SCREEN Point System OSSD outputs to turn or remain OFF,
sending a stop signal to the guarded machine . To restore the
EZ-SCREEN Point System to Run mode, all errors must be
corrected and a manual reset must be performed .
Machine primary control element (MPCE): An electrically pow-
ered element, ex ter nal to the EZ-SCREEN Sys tem, which di rect ly
con trols the machine’s nor mal operating motion in such a way
that it is last (in time) to operate when motion is either initiated or
arrested .
Machine response time: The time between the interruption by the
EZ-SCREEN OSSDs and the instant when the dan ger ous parts of
the machine reach a safe state by being brought to rest .