Smart Process Gating
Leuze electronic GmbH + Co. KG
MLC 530 SPG
21
4.2
SPG requirements
General requirements
SPG is used for access guarding for material transport into or out of danger zones. Thus, as with muting,
the following prerequisites are to be satisfied:
• The transport material must completely fill the opening that is to be safeguarded during passage. The
distance to the fixed parts of the protective device must be less than 200 mm. If that cannot be en-
sured, other measures are necessary, e.g.:
• Wicket gates whose actuation is monitored by a safety sensor.
• Additional vertically mounted protective sensors for monitoring the gaps.
WARNING
Severe injuries when riding along on or next to the conveyor belt!
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Make certain that it is not possible for persons to enter or to ride along on and next to the
conveyor belt or transport material during SPG operation.
SPG requirements
SPG can only be used if the following is known to the control:
• The times at which the position of the transport material is no more than 200 mm in front of and no
more than 200 mm after the electro-sensitive protective equipment (ESPE) are known to the control. In
some cases, additional measures may be necessary for position determination, e.g., trigger, sensor,
etc.
• If additional measures are necessary for position determination, they must not come from a source that
is easily tampered with.
If necessary, use the evaluation of additional information, e.g., belt movement signal.
WARNING
Reduce conveyor speed!
If the time at which the object exits the protective field is not known to the control, the conveyor
speed must be reduced to the maximum value that is permissible for automatic gating end:
Operating modes 1, 6: 0.1 m/s
Operating mode 4: 0.4 m/s
Operating mode 5: 0.2 m/s
NOTICE
Transmitter and receiver of the protective device must be mounted in such a way that they can-
not be pushed or damaged by the transport material.
The prerequisites for SPG operation often exist in, e.g., the following applications:
• When exiting a processing cell, the control usually knows when the processing time ends and when the
drive of the transport system must be switched on.
• In the area of conveyor lines, e.g., with cross conveyors, the exact sequence and the precise position
of the transported goods are usually known. With this knowledge, the CS switching signal necessary for
SPG operation can be generated in the control.
Prerequisites for CS switching signal generation
• The CS switching signal may only be generated if the transport material is less than 200 mm away from
the protective field. This prevents people from entering the danger zone while gating is activated.
• The CS switching signal must, e.g., be generated automatically from the process sequence or derived
in the control through time extension.
• The transport material must trigger the protective field violation (PFI) in less than 4 s (2 s in operating
mode 4) after the CS switching signal.
• To prevent persons from entering the danger zone after the end of gating, it must be ensured that the
transport material is less than 200 mm away from the protective field after the end of gating.
