Rockwell Automation Allen-Bradley 140M, User Manual

Page: 30 / 192

30 Rockwell Automation Publication 450L-UM001F-EN-P - March 2022
Chapter 4 Safety Function
Two setups that cause a teach-in blanking error:
• Case A: Number of objects > 4
• Case B: Top and Bottom end interrupted.
Figure 13 - Teach-in Blanking Error
Table 6 on page 33 shows the reaction of the OSSD outputs with Fixed Blanking
deactivated and activated for different use cases.
Teach-in Blanking Procedure
The procedure to teach a new fixed blanked object is similar to the procedure
to conduct a confirmation of a changed configuration (
Confirmation of a New
System Configuration on page 59 ) with the help of the optical push button.
The optical push button ( Figure 14 on page 31 ) must be activated two times for
5 seconds ( Figure 15 on page 31 ). Between the two activations, a break of a
maximum of 2 seconds is allowed. The following two descriptions describe the
same process that is shown in
Figure 15 on page 31 .
IMPORTANT Fully test the protective field with the provided test rods according to
the instructions given in
Regular Inspection on page 109 .
The configuration and activation of fixed blanking creates a hole to the
left and/or right of the object in the protective field. (Objects are
indicated in black in
Figure 13 on page 30 .) If the fixed object that is in
the protective field does not entirely fill the area between the
GuardShield transmitter and receiver, it is necessary to obstruct access
to the hazard by additional means. Hard guarding the open area can
accomplish this obstruction. Open areas are indicated blue in
Figure 13
on page 30 .
Hard guards refer to mechanical barriers.
ATTENTION: A fixed blanking zone changes the resolution of the 450L-E
safety light curtain system (see Resolution with Blanking on page 34 ). This
change must be considered when calculating the safety distance.
A B