3.3 System Description
Note: This manual refers to an emitter and its receiver, and their cabling as "a System".
Banner EZ-SCREEN LPM emitters and receivers provide a redundant, microprocessor-controlled, opposed-mode
optoelectronic "curtain of light", or "safety light screen". EZ-SCREEN LPM typically is used for safeguarding applications
where the temporary suspension of the safeguard (muting) is periodically required.
CAUTION:
• Mute status must be readily observed
• Failure of the mute indicator should be detectable from the location of the muted device and
prevent the next mute.
• Verify the indicator's operation at suitable intervals. Provide easily observed indication that the
safety device is muted. Select lamp monitoring if the application requires compliance with UL
61496.
The EZ-SCREEN LPM is a two-piece (two-box) system comprising an emitter and a receiver, but no external controller. The
external device monitoring (EDM) function ensures the fault detection capability required by EN ISO 13849-1 Categories 3
and 4 without a third box, a controller or a "smart" (self-checking) safety module required of systems without EDM.
The EZ-SCREEN LPM emitters have a row of synchronized modulated infrared (invisible) light-emitting diodes (LEDs) in a
compact metal housing. Receivers have a corresponding row of synchronized photodetectors. The light screen created by
the emitter and receiver is called the defined area; its width and height are determined by the length of the sensor pair and
the distance between them. The low-profile housing provides maximum sensing within minimum space; its defined area
(sensing area) is equivalent to the height of the housing. The maximum sensing range is 7 m (23 ft), which decreases if
corner mirrors are used. The sensing area extends from end to end of the housing; there is no “dead zone.” Specialty
brackets allow easy mounting of sensors.
In typical operation, if any part of an operator’s body (or any opaque object) of more than a pre-determined cross section is
detected, the solid-state Output Signal Switching Device (OSSD) safety outputs turn OFF. These safety outputs are
connected to the guarded machine’s Final Switching Devices (FSDs) that control the machine primary control elements
(MPCEs), which immediately stop the motion of the guarded machine.
The EZ-SCREEN Low-Profile System with Integral Muting monitor the redundant mute device inputs and automatically
suspend the safeguarding function of a device during the non-hazardous portion of the machine cycle.
In this manual, the term
muting
refers to the automatic suspension of the safeguarding function of the EZ-SCREEN LPM
during a non-hazardous portion of the machine cycle where personnel are not exposed to harm.
The muting function allows material to be manually or automatically fed into or removed from a machine process, without
tripping the EZ-SCREEN LPM. The EZ-SCREEN LPM accomplishes this by using redundant microprocessors that monitor
the status of inputs and outputs, so that a single fault will cause the receiver to issue a stop command to the machine. The
EZ-SCREEN LPM, like all Banner safety products, is extensively Failure Mode and Effects Analysis (FMEA) tested to
establish an extremely high degree of confidence that no internal component will, even if it does fail, cause a failure to
danger. This design philosophy aids machine designers to comply with U.S. control reliability and worldwide standards for
the highest level of safety.
Electrical connections (power, ground, inputs, and outputs) are made via M12 (Euro-style) quick-disconnects or unique RD
(removable disconnect) cordsets, depending on model.
Functions such as Trip/Latch select, Display Invert, Safety Mute Function, Fixed Blanking, Reduced Resolution, Scan Code
Select, and External Device Monitoring are described in
(p. 13) . An auxiliary (aux.) output may be
used to signal the state of the OSSDs to a process controller. All models require a supply voltage of +24V dc ±15%.
Both the emitter and the receiver feature 7-segment diagnostic displays and individual LEDs to provide continuous
indication of operating status, configuration, and error conditions.
3.4 Standard Emitter and Receiver Models—14 mm
Resolution
Pigtail QD Emitter models require mating cordsets with an 8-pin M12/Euro-style connector such as QDE-8..D.
Pigtail QD Receiver models require mating cordsets with a 12-pin M12/Euro-style connector such as QDE-12..D.
EZ-SCREEN Low-Profile System with Integral Muting
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