Honeywell SYA14 Series Manual page 571

TIMING CONDITIONS
•
The 8 ms minimum time difference between the two SMs inputs guarantees the
detection of a permanent short circuits of one or both of the SMs inputs. Physically,
the 2 sensors must be slightly apart.
•
If a new transition of a sensor SM occurs during a muting sequence, the muting
sequence is immediately stopped to avoid the permanent muting of the safety
function. The relative position of sensors SMs and EMs define a minimum distance
between 2 successive moving objects.
•
In the conveyor mode, the object must interrupt the safety light curtain detection
beams, before releasing both sensors SMs and 6s max. after the actuation of the
second sensor SMs.
One-way muting using 2 sensors
The following example is a variant of the previous application, where two thru-scan (or
retro-polarized) photoelectic controls SM1 & SM2 are used to start a muting sequence
and where the electrical connections are made in such a way that the release of the
protective equipment beams stops the muting sequence (refer to the figure 4.18 of the
chapter 4.9.1 Use in the conveyor mode). The sensors could also be ultrasonic sensors,
inductive proximity sensors or limit switches (correct operation of these sensors is
monitored by the muting module). This installation enables the muting of the protective
equipment in one direction only. It is recommended on applications where the entry and
the exit points of the material into the dangerous zone are different.
IMPROPER INSTALLATION
•
The distance between sensors SM1 & SM2 shall not allow a person to actuate both
sensors within the preset time frame.
•
Both beams must be interrupted within a preset time frame 8 ms < t < tmax. The
setting of the timing tmax also sets the muting maximum duration ∆max : select the tmax timing
corresponding to the shortest muting duration ∆max enabling the object transfer (refer to
chapter 2.4.2 SM inputs).
Failure to comply with these instructions could result in death or serious injury.
ADDITIONAL PROTECTIONS
Additional hard guardings must be designed and installed in such a way that people
cannot enter the dangerous area without being detected by the protective equipment.
Particularly, a person following parts vehiculed towards the dangerous zone shall be
detected when interrupting the safety light curtain detection field.
Failure to comply with these instructions could result in death or serious injury.
107004-15 EN FR26 ROW 0899 Printed in France 37