Fault Tolerance - SICK TR4 Betriebsanleitung

GB
Chapter 5
WARNING
146
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Electrical installation
5.2

Fault tolerance

If the device does not appear to function after the application of the
supply voltage (e.g. Status/Diag LED does not flash), the safety
switch must be replaced.
The supply voltage is reverse-polarity protected. The contacts
In A/In B and Out A/Out B are short-circuit protected.
A cross-circuit between In A and In B or Out A and Out B is detected
by the safety switch. A cross-circuit in the cable can be prevented by
laying the cable with protection.
A short-circuit on In A or In B to 24 V DC is detected. It is imperative a
simultaneous short-circuit on In A and In B to 24 V DC is excluded by
laying the cable with protection.
Cables must be laid with protection!
To prevent the accumulation of errors, for applications as per SIL3
(IEC 61 508) and category 4 (EN ISO 13 849) it is imperative to lay the
cables with protection.
Operating Instructions
TR4
8014465/2012-05-07
Subject to change without notice