4.4.4
Cascading
Important information
DANGER
Risk of ineffectiveness of the protective device
The length of cable between 2 cascaded systems must not exceed 3
m.
b
Use the shortest possible cables between the devices of a cascaded system.
b
Protect the cascaded system from manipulation with an optimized length of cable
or with cable routing under a cover.
DANGER
Hazard due to lack of effectiveness of the protective device
Persons and parts of the body to be protected may not be recognized in case of non-
observance.
b
Maintenance work, alignment work, fault diagnoses, and any changes to the inte‐
gration of the protective device in the machine must only be carried out by quali‐
fied personnel.
b
The effectiveness of the protective device must be checked following such work.
NOTE
When 2 or 3 safety light curtains are used in a cascade and the connecting cables are
later interchanged, if may be necessary to deactivate any guest configurations and
manually re-teach the restart interlock.
Integrating a safety light curtain in a cascade
Cascading allows up to 3 safety light curtains to be connected, e.g.
for reliable pres‐
ence detection. The connected devices act like a long safety light curtain. Only one
device, the host, is connected to the control cabinet. The second device, guest
1, is
connected to the host. The 3rd guest
2, is connected to guest
1.
Advantages of cascading:
•
Rapid connection, no additional external circuitry required
•
No optical mutual interference between the protective fields within a cascade.
Host and guests are operated automatically and without configuration with the
alternating beam coding.
•
Resolution and protective field heights of the individual systems may be different
PROJECT PLANNING
4
8012624/10OM/2018-08-09 | SICK
O P E R A T I N G I N S T R U C T I O N S | miniTwin4
35
Subject to change without notice
