98
P/N 133487
Banner Engineering Corp.
•
Minneapolis, U .S .A .
www .bannerengineering .com • Tel: 763 .544 .3164
SC22-3 Safety Controller
Instruction Manual
Appendix A
A.11.6 Mute on Power-Up
If selected, the Mute on Power-Up function will initiate a mute
when power is applied, the Mute Enable input is closed (if
configured), the safety device inputs are active (closed), and
either M1-M2 or M3-M4 (but not all four) are closed .
If Auto Reset is configured, the Controller allows 2 seconds for
the input devices to become active (closed) to accommodate
systems that may not be immediately active at power-up .
If Manual Reset is configured, the first valid reset after the output
device is active (closed) will result in a mute cycle if all other
conditions are satisfied .
WARNING . . .
Mute on Power-Up
The Mute on Power-Up function should be used
only in applications where:
• Muting the System (M1 and M2 closed) when power is applied
is required, and
• Using it must not, in any situation, expose personnel to any
hazard.
A.11.7 Corner Mirrors, Optical Safety Systems, and Muting
Mirrors are typically used with safety light screens and
single-/multiple-beam safety systems to guard multiple sides
of a hazardous area . If the safety light screen is muted, the
safeguarding function is suspended on all sides . It must not
be possible for an individual to enter the guarded area without
being detected and a stop command issued to the machine
control . This supplemental safeguarding is normally provided
by an additional device(s) that remains active while the Primary
Safeguard is muted . Therefore, mirrors are typically not allowed
for muting applications .
A.11.8 Multiple Presence-Sensing Safety Devices
Muting multiple presence-sensing safety devices (PSSDs) or a
PSSD with multiple sensing fields is not recommended unless it
is not possible for an individual to enter the guarded area without
being detected and a stop command issued to the machine
control . As with the use of corner mirrors (see Section A .11 .7),
if multiple sensing fields are muted the possibility exists that
personnel could move through a muted area or access point to
enter the safeguarded area without being detected .
For example, in an entry/exit application where a pallet initiates
the mute cycle by entering a cell, if both the entry and the exit
PSSDs are muted, it may be possible for an individual to access
the guarded area through the “exit” of the cell . An appropriate
solution would be to mute the entry and the exit with separate
safeguarding devices .
WARNING . . .
Guarding Multiple
Areas
DO NOT safeguard multiple areas, with mirrors or
multiple sensing fields, if personnel can enter the hazardous
area while the System is muted, and not be detected by
supplemental safeguarding that will issue a stop command to
the machine.