6
Operating instructions
Safety light curtain / safety light grid
SLC440COM Series
SLG440COM Series
EN
Calculation of the safety distance to ISO 13855 and ISO 13857
The safety distance depends on the following elements:
• Stopping time of the machine (calculation by run-on time
measurement)
• Response time of the machine and the safety light curtain and the
downstream safety-monitoring module (entire safety guard)
• Approach speed
• Resolution of the safety light curtain
Calculation of the safety distance for safety light curtains
SLC440COM
The safety distance for resolutions 14 mm up to 40 mm is calculated by
means of the following formula:
(1) S = 2000 mm/s * T + 8 (d - 14) [mm]
S = Safety distance [mm]
K = Approach speed
T = Total reaction time (machine run-on time, reaction time of the safety
guard, relays, etc)
d = Resolution of the safety light curtain
The approach speed is covered with a value of 2000 mm/s. If value S ≤
500 mm after the calculation of the safety distance, then use this value
If value S >= 500 mm, recalculate the distance:
(2) S = 1600 mm/s * T + 8 (d - 14) [mm]
If the new value S > 500 mm, use this value as safety distance
If the new value S < 500 mm, use a minimum distance of 500 mm
Example:
Response time of the safety light curtain = 10 ms
Resolution of the safety light curtain = 14 mm
Stopping time of the machine = 330 ms
S = 2000 mm/s * (330 ms + 10 ms) + 8(14 mm - 14 mm)
S = 680 mm
S = > 500 mm, therefore new calculation with K = 1600 mm/s
S = 544 mm
Safety distance to the hazardous area
Limit of the hazardous
point
Safety distance (S)
Protection field
marking
Tool - upper part
Signal to stop the
hazardous movement
Standstill of the hazardous
movement
t
n
= t
B
- t
A
Tool - lower part
t
A
S
t
B
≤ 75 mm = max. distance for protection against stepping over
To prevent persons from stepping over the protection field this dimension must be
imperatively respected and observed
4.3 Alignment of the sensors
Procedure:
1 Emitter and receiver must be fitted parallel to each other and at the
same height
2 First turn the emitter and then the receiver so that the front covers
are opposite each other until the integrated signal lamp lights up
green (operating mode automatic) or yellow (operating mode restart
interlock)
3 Adjust the emitter and receiver so that they are in the middle of the
angular range for a green or yellow indication Fix the position with
the two screws for each mounting bracket
4.4 Setting mode
In this operating mode, the signal strength is indicated by blue light
pulses on the indicator; the safety switch outputs OSSD always remain
in the OFF state The better the alignment, the higher the frequency of
the light pulses Alignment is optimal when the pulsed signal switches
over to continuous light If there is no optical synchronisation between
the emitter and the receiver, a light pulse is emitted every three
seconds
4.4.1 Automatic setting mode
To activate the setting mode, the lower beam of the AOPD (seen from
the connecting cable side) must be interrupted for 10 seconds on
system start-up
Once the setting mode has been started, there will be a blue light pulse
from the signal light
If there is sufficiently good alignment for a period of 20 seconds, the
setting mode will be terminated automatically, whereupon the AOPD will
restart with a reset followed by a self-test
4.4.2 Activating setting mode with 5-pin cable connection
Apply a voltage of +24V on the "Reset" input for at least 2 seconds
when the system starts (eg by pressing the reset pushbutton) The
receiver unit starts in setting mode The pushbutton can be released as
soon as the indicator changes from red to blue
Display
Blue indicator
Signal status
static ON
best possible
pulses at 20 Hz
Good
pulses at 10 Hz
adequate
1 Hz
signal strength too low
(signal reserve, contamination)
1 pulse every three
seconds
no signal
4.5 Safety distance
The safety distance is the minimum distance between the protection
field of the safety light curtain and the hazardous area The safety
distance must be observed to ensure that the hazardous area cannot
be reached before the hazardous movement has come to standstill
The safety distance between the safety light curtain / light
grid and the hazardous point must always be respected and
observed If a person reaches the hazardous point before the
hazardous movement has come to a standstill, he or she is
exposed to serious injuries
To calculate the minimum distances of the safety guards with
regard to the hazardous point, ISO 13855 and ISO 13857
must be observed
