Figure 2. Typical Application
3.3.2 Examples: Inappropriate Applications
Do not use the S4B in the following applications:
•
With any machine that cannot be stopped immediately after a stop signal is issued, such as single-stroke (or full-
revolution) clutched machinery
•
With any machine with inadequate or inconsistent machine response time and stopping performance
•
With any machine that ejects materials or component parts through the defined area
•
In any environment that is likely to adversely affect photoelectric sensing efficiency. For example, corrosive chemicals
or fluids or unusually severe levels of smoke or dust, if not controlled, may degrade sensing efficiency
•
As a tripping device to initiate or reinitiate machine motion (PSDI applications), unless the machine and its control
system fully comply with the relevant standard or regulation (see OSHA 29CFR1910.217, NFPA 79, ANSI B11.19,
ISO 12100, IEC 60204-1, IEC 61496-1, or other appropriate standard)
If the S4B is installed for use as a perimeter guard (where a pass-through hazard may exist, see
on page 18), the dangerous machine motion can be initiated by normal means only after the
safeguarded area is clear of individuals and the external safety monitoring device has been manually reset.
3.4 Control Reliability: Redundancy and Self-Checking
Redundancy requires that S4B circuit components be backed up to the extent that, if the failure of a single component will
prevent effective machine stopping action when needed, that component must have a redundant counterpart which will
perform the same function. The S4B is designed with redundant microprocessors.
Redundancy must be maintained whenever the S4B is in operation. Because a redundant system is no longer redundant
after a component has failed, S4B is designed to monitor itself continuously. A component failure detected by or within the
self-checking system causes a stop signal to be sent to the guarded machine and puts the S4B into a Lockout condition.
A recovery from this type of Lockout condition requires:
•
Replacing the failed component (to restore redundancy), and
•
Performing the appropriate reset procedure.
3.5 Operating Features
The sensing resolution is determined by the emitter and receiver model.
WARNING:
•
Use of automatic (trip) or manual (latch) start/restart
•
Failure to follow these instructions could result in a serious injury or death.
•
Applying power to the Banner device, clearing the defined area, or resetting a latch condition must
not initiate dangerous machine motion. Design the machine control circuitry so that one or more
initiation devices must be engaged to start the machine (a conscious act), in addition to the
Banner device going into Run mode.
Emitter Wiring Options
—An S4B emitter can be connected either to its own power supply or to the receiver cable, color-for-
color. The color-for-color wiring allows the emitter and receiver positions to be interchanged without rewiring.
Status Indicators
—Status indicators on both the emitter and receiver are clearly visible on each sensor’s front panel.
S4B Safety Light Curtain
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