Pinnacle Systems CA - Manual (Page 8)

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Introduction
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Introduction
Model CA Product Overview
Cascading safety light curtains provide the user the
ability to connect additional sets of light curtains
by daisy chaining multiple emitters and receivers
together. The interconnecting cables are factory
supplied and the user defines length. The
cascading of safety light curtains provides mulitple
areas of guarding in any plane (X, Y, Z), while
utilizing the control reliable dual safety outputs
from the Category 4 safety device for the safety
outputs to the machine control. The ability to guard
multiple areas on irregular shaped machines by
cascading safety light curtains reduces wiring
and provides a lower cost yet effective machine
guarding solution.
The Model CA Cascading Safety Light Curtain is an
infrared safety light curtain that is designed
to the IEC 61496 standard. When properly
installed, it protects the machine operator by
passing an invisible infrared light beam across
an area to be guarded and examining whether
or not the light beam(s) are blocked. If the light
beam(s) are blocked, monitored solid state
outputs will open, issuing a “STOP” command
to the machines normally closed (N.C.) “STOP”
circuit. The Model CA System is composed of
transmitting units (EMITTERS), and receiving
unit (RECEIVERS). The entire system is control
reliable Category 4 (per IEC 61496). A single fault
anywhere within the Model CA will not prevent at
least one of the solid state outputs from opening
up, (allowing a “STOP” command) when either
a beam is broken or an internal fault occurs.
Theory of operation.
The Model CA Cascading Safety Light Curtain protects
an area by projecting a curtain of infrared light.
The infrared emitters and receivers face each
other across the fi eld to be protected. Each LED
pair is spaced along the length of the pylons
at regular intervals from .5” (12mm), up to 8”
(203mm) depending on the application. The
smaller spacing are for fi nger guarding, the larger
spacing are for body protection. The emitter/
receiver pairs are scanned sequentially (one at a
time) by a very short pulse of infrared light starting
from bottom (cable end), and working up to the
end, until every beam pair has been scanned. Two
16 bit computers in the fi rst emitter pylon and two
16 bit computers in the fi rst receiver pylon control
the operation, as well as cross check each pylon.
The System.
The Model CA Cascading Safety Light Curtain employs
infrared technology in a small sealed NEMA 4 (IP
67) aluminum housing with an infrared passing
(daylight filtering) acrylic lens. This system
provides harmless invisible protection and an
unobstructed view of the guarded area. There are
two parts to the Model CA: An Emitter pylon and a
Receiver pylon. The Emitter pylon has no outputs.
The Receiver pylon contains two monitored
solid state 24vdc outputs. Both pylon sets are
synchronized to each other electronically as they
are connected together with the interconnect cables
to the top and bottom of the next set of pylons.
System Safety.
The Model CA Cascading Safety Light Curtain
i n c o r p o r a t e s r e d u n d a n t , a n d d i v e r s e
technology that provides a backup for every
system that could cause an unsafe condition.
External Device Monitoring (EDM).
A method in which the Model CA Category 4 cascading
safety light curtain logic monitors the state of
various external control devices. The control
devices are external and not part of the Model
CA light curtain pylons. A lockout or stop signal
will result if an unsafe state is detected in an
external device. The External Device Monitoring
(EDM) is an optional function of the Model CA
safety light curtain for monitoring the status of
external devices such as gate and door switches,
safety switches or the main control element of the
drive (MPCE). Solid state outputs are turned on
separately to be checked and to assure neither
output has been shorted, before fully turning on.
Design Criteria.
Designed to meet IEC 61496-1 & 2, UL 1998, UL subject
491, OSHA, ANSI, CSA, ANSI-RIA R15.06-1999
Microprocessor redundancy for both Emitter and
Receiver pylons
Redundant, monitored, 24vdc solid state outputs (PNP)
Watchdogs on CPU’s and outputs prevent unintentional
output during lockups.