Omron MiniSafe 4800 Series Installation And Operating Manual page 20

5 D
ETECTION
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5 .1 F
A Fixed Blanking pattern may consist of more than one Fixed Blanked area. Individual Fixed Blanked
OMRON Scientific Technologies Inc. Fremont CA USA
USA: 800.556.6766 Canada:866.986.6766
Mexico and South America: 847.843.7900 All other countries: 510.608.3400
O
PTIONS
Warning!
Use of Fixed or Floating Blanking, Floating Blanking and Reduced Resolution will
make an MS4800 system less sensitive to objects in the detection zone. Improper use of these
features can result in severe injury to personnel. Fixed Blanking may require a hard barrier
guard. Fixed Blanking, Floating Blanking and Reduced Resolution may require an increase in the
safety distance. Read the following section carefully.
B
I X E D L A N K I N G
Fixed Blanking is only available on MS4800A and MS4800S systems.
Additional Hard Guarding
Light Curtain
Figure 5-1 Adding Hard Guarding to Light Curtain when Using Fixed Blanking
Fixed Blanking allows a system to blank optical beams and record the exact pattern. A system can
record and store a single pattern. The protected zone's object detection is then based on the stored
pattern. All obstructed optical beams recorded during the selection must remain blocked and all clear
beams recorded during the selection must remain clear for the system to enter or remain in the
MACHINE RUN state.
areas must be separated by at least one beam that is always clear. A Fixed Blanking area may not
crossover between "flexible" segment boundaries.
"Each Fixed Blanked area has a size and positional tolerance of +/-1 beam to allow for small positional
variations where only the beams on the edges of the blanked area are allowed to change. Because of
this position tolerance, a reduction of the optical resolution occurs on the border areas of the Fixed
Blanking patterns. See Table 5-1 Tolerance Effect of Fixed Blanked area on Resolution. The effect of
this tolerance also allows the number of blocked beams to change by +/- 1 beam. For example, a Fixed
Blanked area of 8 blanked beams is allowed to increase to 9 beams or decrease to 7 beams and the light
curtain will remain in MACHINE RUN." If there is a one or two beam gap between objects the objects
cannot use their beam tolerances to close the gap and combine into one single fixed blanking area. In
addition if there is a one beam gap between objects, the object closest to the entry encap cannot use the
clear beam towards its tolerance even if the adjacent object moved in the same direction by one beam.
Obstruction
Light Curtain
17
5
© OMRON STI 0715 PN99804-0010 Rev. R