Wintriss Shadow VI, User Manual

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Shadow VI User Manual 1107200
Introduction to Shadow VI Chapter 1 page 7
Safety Light Curtain
NOTICE
The Occupational Safety and Health Administration (OSHA) and the American National
Standards Institute (ANSI) have issued regulations for the use of presence-sensing devices
such as Shadows. Both of them require control reliability. See Appendix A for more
information.
Control reliability means "the device shall be constructed so that a failure within the system
does not prevent the normal stopping action from being applied to the press when required,
but does prevent the initiation of a successive stroke until the failure is corrected."
Control reliability is another reason why Shadow is an excellent machine guard. All critical
components in Shadow are duplicated so that if one fails, the other will still allow normal
operation to stop the machinery. If a component failure does occur, Shadow will immediately
detect the failure and send a stop signal to the machinery. The light curtain will not allow
operation until the repairs are made.
Another example of control reliability are Shadow's control relays. The control contains
captive-contact relays (2 stop and 1 status relay). The N/O outputs are connected in series to
the press's emergency stop circuit and are always energized (contacts held closed) when the
light field is
not broken. When an obstruction enters the field, Shadow's control circuitry
instantly de-energizes the relays, which results in opening the contacts and breaking the stop
circuit of the press. Shadow's response time from loss of light to relay contacts open is 30 to
40 milliseconds (depending on the size of the optic heads). Even if one of Shadow's control
relay contacts fails closed (contact welds shut), the second relay will still de-energize and a
stop signal will be sent to the machinery. Shadow will also detect the failed relay. It will not
allow further press operation until the relay is replaced. It is highly unlikely that the relay
contacts will fail simultaneously.
Description of Shadow VI indicators
Shadow includes several indicators. Figure 1-1 shows the indicators on the transmitter and
receiver, and Figure 1-2 illustrates the control.
These indicators communicate Shadow's operating status. Use them to troubleshoot your
light curtain (see Chapter 4 troubleshooting guides). If any contradiction exists between the
indicator lights at the receiver and those at the control, make sure you compare your findings
with the information in these troubleshooting guides to solve the problem immediately.
At the Optic Heads
The transmitter has an amber-colored power indicator which remains illuminated when
Shadow has power. There are three indicators on the front of the receiver. The red
indicator means that the light curtain has been interrupted. The orange indicator flashes
when the floating window option is turned "on" at the control (see Chapter 2). The green
indicator means the light curtain is unobstructed.