Assembly; Calculating The Safety Distance / Total Reaction Time (Total Response Time) For As-Interface Applications - Siemens SIGUARD LS4-4 Anleitung

4.2

Assembly

See in this connection chapter 5, "Planning and assembly instructions", of the LS4-4
Technical Manual.
To assemble the LS4 AS-Interface you should use rather long fastening screws,
with a length of at least 50 mm and a diameter of 5 mm; in other respects the as-
sembly instructions for the SIGUARD LS4 laser scanner will apply here as well. The
borehole measurements may be seen from the scale drawings in chapter 7.
4.2.1 Calculating the safety distance / total reaction time (total response time)
for AS-Interface applications
In general terms, the calculation that applies is in accordance with the following
formula, in keeping with EN 999, where S is the safety distance between the danger
zone and the protective field:
S = (K xT) + C
C = 1200 mm – 0,4 H
Here
S is the minimum safety distance between protective field and danger zone,
in mm
K is the speed of approach of the person or part of the body, in mm/ms
T is the overtravel time of the machine + the reaction time of the optoelec-
tronic protective device (AOPD) + the reaction time of the AS-Interface
bus system in ms
C is a safety-related constant, to take into account penetration of the danger
zone before the protective facility is triggered, unit in mm
C is the minimum value of the safety-related constant (850 mm), unit in mm
MIN
H is the height of the registration of measurement data taken from the
reference point, unit in mm
d is the resolution of the scanner (70 mm, covering the entire protective
field), unit in mm
See in this connection chapter 5.4.8 of the Technical Manual for the SIGUARD LS4
laser scanner
The additional bus system reaction time that is required by the AS-Interface and the
AS-Interface safety monitor, coming to a maximum of 40 ms (when the full resources of
the AS-Interface system are installed, with 31 slaves), must be added to the response
time T.
C = 850 mm
MIN
H = 15(d - 15 mm)
MIN
H = 1000 mm
MAX
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