The Model SS 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 System is composed
of a transmitting unit (EMITTER), and a receiving unit (RECEIVER). The
entire system is control reliable Category 4 (per IEC 61496). A single
fault anywhere within the Model SS 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 SS protects an area by projecting a curtain of infrared light.
The infrared emitters and receivers face each other across the field to
be protected. Each emitter/receiver pair is spaced along the length of
the pylons at regular intervals from .5", up to 8" depending
on the application. The smaller spacing are for finger 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 top, until every beam pair
has been scanned. Two 16 bit computers in the emitter pylon and two 16
bit computers in the receiver pylon control the operation, as well as
cross check each pylon.
The System.
The Model SS employs infrared technology in a small sealed NEMA 4 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 SS: An Emitter pylon
and a Receiver pylon. The Emitter pylon has no outputs, but does contain
a digital CAN data network to allow it to be linked to the Receiver pylon
(although not required for operation). The Receiver pylon contains the
digital CAN data network and two monitored solid state 24vdc outputs.
Both pylons are synchronized to each other either via the CAN data network
or electronically.
System Safety.
The Model SS incorporates redundant, and diverse technology that provides
a backup for every system that could cause an unsafe condition. In the
Emitter pylon, 1 CPU drives the Infrared LED’s while the 2nd CPU
monitors to assure proper signals and timing. Improper operation from
either CPU will turn off the Infrared LED’s. In the Receiver pylon,
1 CPU drives the Infrared receivers while the 2nd CPU monitors to assure
proper signals and timing. Both CPU’s are required to drive the
solid state outputs as well as monitor the condition of the output. Either
CPU can shut down both solid state outputs. Signals shared between CPU’s
are isolated from each other to prevent a failure of 1 microprocessor
causing a failure in the 2nd. Watchdog circuits on the solid state outputs
automatically shut off the outputs should either CPU slow down or lock
up. Solid state outputs are turned on separately to be checked and 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.
Safety Light Curtains • Safety Mat Systems • Ergonomic Palm
Buttons
Punch Press Automation Controls • Punch Press Guards and Controls
Press Brake Guards and Controls
Robotic, Automation and Special Machine Guarding Systems
All products are manufactured to meet or exceed all applicable OSHA and ANSI
standards and are made in the U.S.A.
To speak
to a sales representative in the United States, please call (800) 569-7697.
Request a catalog
or price quote online or send an e-mail.
