Fig. 15 Route Signal Lines Incorrectly - Beckhoff EK1914 Operating Manual

Fig. 15: Route signal lines incorrectly
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A common signal routing with other clocked signals in a bus also reduces the maximum extension. The
reason for this is that crosstalk of the signals may occur on a long line length and diagnostic messages
appear. If the connection via a bus line is unavoidable, the test pulses can be switched off (Sensor test
parameter). However, this then leads to a reduction in the diagnostic coverage when calculating the
performance level.
The use of contact points, connectors or additional switching contacts in the cabling also reduces the
maximum expansion.
The typical length of a test pulse (switching from 24 V to 0 V and back to 24 V) is approximately 380 µs and
occurs about 400 times per second.
In the step mat mode (parameter: "Short cut is no module fault"), test pulses with a typical length of 750 µs
are generated in addition to the typical test pulse lengths of 380 µs.
EK1914
Distance between cable ducts
Signature lines
Potential sources of interference
Version: 2.0.0
Installation
35