Diagnostics For Changeover Contact Sensor Type - Siemens SIMATIC ET 200SP HA Manual

5.3

Diagnostics for changeover contact sensor type

Diagnostics for change-over contact sensor type
With the change-over error diagnostics, the switchover between two input channels is checked.
If there is a signal change in a change-over contact channel and there is no signal change at
the other contact change-over channel after the tolerated switchover time, the diagnostics
module returns a change-over error.
The tolerated switchover time between the two channels is set to the fixed value of 300 ms.
Change-over sensors are always assigned to two adjacent channels: The NO channel is set
according to the encoder type on channel 0, 2, 4, 6, 8, 10, 12 or 14, the respective associated
NC channel 1, 3, 5, 7, 9, 11, 13 or 15 must be deactivated.
Principle of change-over contact diagnostics
If the digital inputs of a channel group are configured as "change-over contacts", the module
for this channel group carries out diagnostics for the change-over contact sensor type.
If the plausibility check is negative, the following happens:
● The module identifies the value status of the NO channel as "invalid" (QI = "0").
● The module creates a diagnostics entry for the NO channel.
● If the change-over contact error diagnostics is enabled, a diagnostics interrupt is triggered.
The digital input signal and the value status are only updated for the NO channel. The digital
input signal is 0 and the value status is "invalid" (QI = "0") for the NC channel. This channel is
only used for a validity check of the sensor.
Please note the following special features for change-over contact diagnostics:
● If the normally open and normally closed contact signals are not plausible after 300 ms, a
change-over error is output as diagnostics information.
● If there is already a fault (QI = 0, e.g. a wire break), the module will no longer perform
diagnostics for change-over errors.
● There are different diagnostics options depending on the type of change-over contact.
Depending on the sensor type, a change-over error can have different causes.
– In the case of connected change-over contacts, a change-over error may also be the
– In the case of unconnected change-over contacts, a change-over error may also be the
– If a wire break or short-circuit can be detected with the particular sensor type but its
Digital Input Module DI 16xNAMUR HA (6DL1131-6TH00-0PH1)
Manual, 11/2017, A5E39293880-AB
result of a short-circuit (sensor is not defective; there is a short-circuit).
result of a wire break.
diagnostics is not enabled, instead of the wire break or short-circuit diagnostics
information, the change-over error diagnostics information is displayed if this is enabled.
5.3 Diagnostics for changeover contact sensor type
Displays and interrupts
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