IDEC FS1A Controller - Manual (Page 389)

APPENDIX
A-1
APPENDIX
APPENDIX
Minimum Distance
The minimum distance is the distance required to minimize the risk of contact with the hazard in
the danger zone.
Be sure to maintain a sufficient minimum distance while taking into consideration the stopping
time of the entire system, including the reaction time of the SafetyOne and the reaction time of
any connected devices. If sufficient minimum distance is not maintained, the machinery may not
be able to come to the sudden stop before a person meets a hazard, resulting in death or serious
injury.
Calculating the minimum distance when connecting a safety light curtain
■ For ISO 13855-2002
You must take the following 5 points into consideration when determining the minimum distance.
1. Reaction time of the safety light curtain and SafetyOne
(The time it takes for the safety outputs of the SafetyOne are turned OFF after the safety light
curtain is shaded)
2. Stopping time of the machinery
(The time it takes for dangerous machinery operation to come to the stop after the safety
outputs of the SafetyOne are turned OFF)
3. Size of the minimum detectable object of the safety light curtain
4. Speed of the detected object entering the danger zone
5. Height of the maximum allowable optical axis of the safety light curtain
Parameters
S: Minimum distance (mm)
K: Speed of the detected object, arm or leg entering the danger zone (mm/s)
Tc: t1+t2
t1: Reaction time of the SafetyOne (s)
t2: Preset OFF-delay time of the SafetyOne (s)
T1: Reaction time of the safety light curtain (s)
T2: Maximum time from when the safety output of SafetyOne is turned OFF to when the hazard
is stopped (s)
C: Additional distance calculated from the minimum detectable object of the safety light curtain
(mm)
H: Height of the maximum allowable optical axis of the safety light curtain
β: Angle of the ground surface and the safety light curtain to the direction of entry