Chapter
3
Operating Instructions
UE4155
22
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
8010178/TF82/2010-03-05
Subject to change without notice
Product description
3.6
Selection principles
This chapter is intended for production engineers who need information about the
electronic interfaces and their internal circuitry to realise their applications.
All the circuit elements of the bus node with the exception of the field-signal outputs are
protected from a reversal of the voltage supply.
3.6.1
Field-signal inputs
You may use the field-signal inputs to read the statuses of the following types of outputs
that supply electrical power:
contacts at 24 V, e.g. from components with contact outputs that are driven by an
allocated field-signal output
tested 24
D
V-PNP
D
semiconductor-switching outputs, e.g. from SICK C2000/M2000,
C4000, S3000, among others
untested 24
D
V-PNP
D
semiconductor-switching outputs, e.g. photoelectric switches
Properties
8 × 2 field-signal inputs
safe status is 0 V (idle)
inputs at 0 V that draw current
characteristic according to IEC 61 131
D
2, type 2
each input has its own status display
Yellow
input delay (“debouncing”) is configurable (see chapter 3.5.1 “Functions of the field-
signal connections” on page 17)
Possible error detection
The self-test in the bus node detects when a field-signal input cannot return to the safe
status owing to an internal error. Furthermore, the bus node can identify the following
errors:
discrepancy in the case of two-channels (see chapter 3.5.2 on page 19)
cross-circuit on test signals from other field-signal outputs of the bus node
You must take further measures to detect external errors, as described in the sections
below.
Safe reading of contacts at 24 V
In order to detect errors outside the bus node, the corresponding contacts of field-signal
outputs of the bus node must be fed with test signals. Because every field-signal output
uses a different test signal, you must establish at the configuration stage which field-signal
output the contact must use to obtain its test signal.
In a corresponding configuration the bus node can detect an external short-circuit to other
test signals, to 24 V or to ground.
Note