Version 10.12.2019
WERAC Elektronik GmbH
page 17
during safety mode 2, always bypassing is activated. This particularity must be considered in
the risk assessment. See also the safety guidelines at the end of chapter 6.11.5.
As soon as one contact of the active contact pair opens, it is checked if the second contact
pair was closed correctly and another safety mode is requested. If so the safety mode is
passed to the one related to the other contact pair, if not the current mode is stopped and the
light grid guarantees the safety function.
The reduced resolution mode can be activated and deactivated both in OSSD off mode (when
the light grid is interrupted) and in normal mode when the light grid is unobstructed. The
blanking function will only effect the light grid in normal mode.
6.11.7.2 After power ON
A special function is included in the reduced resolution mode after power ON. After system
start and the system self-tests the mode reduced resolution is activated directly if the function
is selected, i.e. both contacts of contact pair 1 are closed/ switched ON.
Once the reduced resolution is activated the same monitoring sequences and operations are
carried out as described in 6.11.7.1.
Caution, risk of injury
When using the switched reduced resolution, in particular the special function after power on it
must be ensured that an accumulation of faults does not lead to a loss of the safety function
for reaching the performance level PL e, category 4 in accordance with EN ISO 13849-1. For
this reason, appropriate measures must be taken on the application side, which may also
include fault exclusions (e.g. at the switches).
Caution, risk of injury
When using the function reduced resolution the lines specified for bypassing were no longer
evaluated, when contact pair 1 is closed. The guarded area then is reduced by the blanked
lines. In the bypassed areas no monitoring takes place. I.e. only when hazards in the blanked
areas can be excluded by using other measures, e.g. a locked and monitored rolling door and
a restart lock, the use of reduced resolution is permitted.
Caution, risk of injury
When using both functions (blanking and bypassing) in mode 2 it must be ensured that the
different priorities of the functions were considered in the risk assessment and the passing
from one function to the other does not generate a hazardous situation.
6.11.8 Operation with Fixed Blanking
If mode 3 has been defined in the teach-in procedure, fixed blanking is permanently active.
This means that the selected lines are always blanked and must be interrupted at all times to
enable the OSSDs.
Caution, risk of injury
When using both functions (fixed blanking and bypassing) it must be ensured that the different
priorities of the functions were considered in the risk assessment and the passing from one
function to the other does not generate a hazardous situation.
7
Commissioning and regular inspections
The commissioning engineer must have all the requisite information on the machine and the
mounted ESPE (ESPE = electro-sensitive protective device, in this case SAFETY 40 safety
light curtain with WGN 100 or WGN 110 control unit) available. The inspection must extend to
the perfect interaction of the ESPE with the controller of the power-driven machinery and the
setup in compliance with these safety regulations. With all inspections always check the safety
guidelines of the machine manufacturer (e.g. the manufacturer of the presses).
