Rockwell Automation 440F MatGuard, 440F-C4000 Mat Controllers - Manual (Page 6)

Section 2 - SYSTEM DESCRIPTION
The system comprises one or more interconnected pressure sensitive mats and a control unit. There are
no 'dead zones' within the detection zone. Individual sensor mat sections are available in rectangular
standard sizes and also in specially cut shapes up to the size of the largest standard mat. All sensor
mats have the same construction and operation principle.
Each mat has two conductive plates which are held apart by non-conductive compressible separators.
The mats operate at 24V DC and are connected together in series to form a floor level sensing system
for hazard areas around machinery. The circuit through the mats is monitored by the control unit which,
when the area is clear, provides a signal to the machine control circuit. When any mat is stepped on, the
conductive plates touch and the resistance in the circuit drops. This is monitored by the control unit
which shuts the machine down. Any single electrical fault in the mat, wiring or control unit will be
detected and the control unit outputs will go to a safe (OFF) state. The moulded vinyl sensor mats are
sealed to IP 67.
440F-C28013 Control Unit
The unit comprises of an eight-channel sensing mat system. When any mat is stepped on the control unit
shuts the machine down and indicates on the CHANNEL FAULT STATUS display which mat is operated.
Two operating modes are available: manual reset and auto reset.
IN MANUAL RESET mode the output 'ON' signal can only be restored after the actuating force has been
removed and after a reset. The manual reset is achieved by pushing and releasing the lid
mounted control unit reset button or a remote mounted button. At power-on or following the loss and
subsequent restoration of power, the outputs will be 'off' until a reset signal is received even if the mat is
not actuated.
IN AUTO RESET mode the output 'ON' signal is achieved solely by removal of the actuating force.
For both modes, the safety contacts will always be 'OFF' (open) after the mat is actuated.
Mode selection is covered in more detail in section 5.
Individual sensor mats connect to each other and to the control unit via 4 wires. The control unit has
cross monitored safety relays and it is possible to configure the unit so that an external contactor fault
will be detected.
Compliance with the requirements of EN 954-1 category 3 is achieved for the control unit regarding
electrical faults and can be met for the associated part of the machine control system. Compliance with
the requirements of EN 954-1 category 1 is achieved for the mat sensors.
Section 5 deals with interfacing in detail. The operating principle of the mat is shown in fig. 1.
Fig. 1
When the mat is activated the non conductive compressible separators (shown black) compress into
their recess allowing the two plates to make contact, giving all over sensitivity.
The system is intended for the detection of adult persons with a weight of 35Kg or more. It is suitable for
the detection of adults using walking aids (walking sticks or frames).
THE SYSTEM IS NOT SUITABLE FOR THE DETECTION OF CHILDREN.
THE SYSTEM MUST NOT BE USED WITH ANY ADDITIONAL COVERING ON THE MAT.
MAT AT REST
STEEL
PLATES
MOULDED
VINYL
MAT ACTIVATED
5