Rockwell Automation 440L GuardShield PAC Type 4 Safety Light Curtain - Manual (Page 8)

GuardShield™ PAC Safety Light Curtain Installation Instructions
6
Original instructions
Examples of Range of Use
The GuardShield PAC safety light curtain operates as a proper
protective device only if the following conditions are met:
• The control of the machine must be electrical.
• The controlled machine must be able to be stopped any
where in the machines stroke or cycle.
• The transmitter and receiver must be mounted such that
access to the hazard is only through the light curtain’s
protective field.
• The restart button must be located outside the hazardous
area such that it cannot be operated by a person working
inside the hazardous area.
• The statutory and local rules and regulations must be
observed when installing and using the device.
Safety Functions
The GuardShield PAC safety light curtain offers a variety of
functions, which are integral to the system.
Operating modes, functions and features of the GuardShield PAC
system are activated through dip switch settings.
Guard Only
When in the guard only mode of operation, the light curtain
operates as an on/off device, meaning the OSSD outputs switch
off/on according to an obstruction or clearing of the detection
field. The GuardShield PAC is shipped from the factory in the
guard only mode.
Start Interlock
The start interlock prevents the OSSD outputs from switching to
ON state after power up of the system with the protective field
unobstructed. A manual reset of the system is required for the
GuardShield PAC to enter the ON state.
This can be accomplished by one of two methods.
• Actuation of a momentary N.O. push button
• Interruption and restoration of the protective field within
one second.
Activation of this mode of operation and selection of the resetting
method is through dip-switch settings. Indication of this mode of
operation is through illumination of a yellow LED on the
GuardShield PAC’s receiver.
Restart Interlock
The restart interlock mode of operation prevents the OSSD
outputs from switching to ON after interruption and clearance of
the protective field. A manual reset of the GuardShield PAC
IMPORTANT
The protective system must be tested for
proper operation after each and every
change to the configuration.
IMPORTANT
Start interlock is not available in GuardShield
PAC light curtains with ArmorBlock Guard I/O
connectivity.
system is required. Resetting of the system is accomplished
through a momentary N.O. push button or key switch.
Configuration and activation of this mode of operation is through
dip-switch settings. The Restart Interlock mode is indicated by the
illumination of a yellow LED on the GuardShield PAC’s receiver.
External Device Monitoring (EDM) or Machine
Primary Control Element (MPCE) Monitoring
The External Device monitoring function (EDM) is an input signal
to the GuardShield receiver from the Final Switching Device (FSD),
usually relay contactors, which control the hazardous motion of
equipment or machinery. The EDM circuit is required to see a
change of state of the FSD within 300ms of the restoration of the
GuardShield’s sensing field after its interruption. Detection of an
unsafe condition such as a welded contact causes the
GuardShield receiver to go to a lockout condition (OSSDs OFF).
The activation and use of this GuardShield functionality usually
allows the GuardShield’s OSSDs to be connected directly to a
machine’s FSD and attain a Category 4 safety circuit. It is necessary
to have the EDM circuit connected to two separate FSDs which
are wired in series to attain the Category 4 rating. Activation of
this functionality is accomplished by setting the EDM dipswitch
no. three to the OFF position and then performing the “Teach”
function. It is also necessary to connect the GuardShield receiver’s
EDM (yellow) wire to a N.C. output from the FSD.
System Testing
The GuardShield PAC performs a complete system self-test at
power up and switches to the ON state if the system is properly
aligned and the protective field is unobstructed and the start/
restart interlock modes of operation are deactivated.
External Test (Machine Test Signal)
A test cycle of the system can be triggered by an external test
signal to the GuardShield PAC’s transmitter. Supplying or
removing a signal (+24V DC) via a N.C. or N.O. switch at the test
input deactivates the transmitter for the duration of the test
signal, simulating an interruption of the protective sensing field.
IMPORTANT
It is not possible to have both “Start Interlock”
and “Restart Interlock” configured at the
same time in the GuardShield PAC.
Configuring “Restart Interlock” behaves the
same as “Start Interlock” at power up, i.e., a
reset of the system is required at power up.
Restart interlock should always be configured
for the GuardShield PAC light curtains. The
reset switch should be located outside of the
work cell and positioned so that a clear view
of the work cell is possible.
Restart interlock is not available in
GuardShield PAC light curtains with
ArmorBlock Guard I/O connectivity. this
functionality must be configured and
through the safety PLC.
IMPORTANT
EDM is not available in GuardShield PAC light
curtains with ArmorBlock Guard
I/O connectivity.