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8
OMRON SCIENTIFIC TECHNOLOGIES INC.
Fremont CA USA
Tel: 1/888/510-4357 in USA and Canada
© OSTI 1209 PN99584-0050 Rev. E
Original Instructions
28
Table 7-1
SWITCH A
SWITCH B
Auxiliary Output Operating Mode
7
7
Auxiliary Outputs on in RUN (Follow) state
OPEN/OFF
OPEN/OFF
Auxiliary Outputs on in FAULT (Alarm) state
CLOSED/ON
CLOSED/ON
Auxiliary Output Operating Mode Switch Settings
NOTE! Replace controller cover and retention screws after changing system configuration. See
Section
for details.
8 S
AFE
M
OUNTING
D
ISTANCE
Li
g
h
t Cu
rt
a
in
D
s
Ds is the minimum s afe dis tanc e
between the light c urtain s ens ing
field and the point of operation
hazard (pinc h point).
8
▲
!
WARNING!
Never install a 4700 system without regard to
the safety distance. If the 4700 system is mounted too close to the
point of operation hazard, the machine may not stop in time to
prevent an operator injury.
A 4700 system must be mounted far enough from the machine
danger zone so the machine will stop before a hand or other
body part reaches the hazardous area. This distance is called
the safety distance. It is a calculated number based on a
formula. See Figure 8-1
for an
illustration of the safety distance.
Regardless of the calculated distance, a 4700 system should
never be mounted closer to the point of operation hazard than
allowed by Table 0-10 in OSHA 1910.217.
Figure 8-1 Safe Mounting Distance
8.1 US S
AFE
D
ISTANCE
F
ORMULAS
In the United States two formulas exist to properly determine the safety distance. STI recommends the
formula provided by the American National Standards Institute (ANSI) which incorporates additional
factors when compared to the formula required by OSHA.
The ANSI formula given below is for a normal approach to the light curtain.
D
s
= K x (T
s
+ T
c
+ T
r
+ T
bm
) + D
pf
Where:
D
s
=
minimum safety distance, in inches, between the 4700 system detection zone and the nearest point
of operation hazard.
K =
hand speed constant in inches per second. The ANSI standard value is 63 inches/second which
assumes the operator starts a hand motion toward the point of operation from rest. According to ANSI
B11.19-1990,
“The value of the hand speed constant, K, has been determined by various studies and
although these studies indicate speeds of 63 in./sec. to over 100 in./sec., they are not considered
conclusive determinations. The user should consider all factors, including the physical ability of the
operator, when determining the value of K to be used.”
T
s
=
the stop time of the press (or machine) in seconds, measured from the final de-energized control
element. Measured at maximum closing velocity.