Siemens SIMATIC ET 200AL, System Manual

Page: 937 / 2255

Parameters/address space
4.3 Explanation of parameters
Digital I/O module F-DI 4+F-DQ 2x24VDC/2A, 4xM12 (6ES7146-5FF00-0BA0)
Equipment Manual, V1.0, 05/2021, A5E51082342-AA
31
"Test 0-signal necessary"
If you have assigned "Test 0-signal necessary", a discrepancy error is not regarded as
corrected until a 0-signal is present at both of the relevant input channels for a duration of at
least 100 ms.
If you are using nonequivalent sensors, which means you have set "Sensor evaluation" to
"1oo2 evaluation, nonequivalent", a 0-signal must be present again at the low order channel
of the channel pair.
"Test 0-signal not necessary"
If you have assigned "Test 0-Signal not necessary", a discrepancy error is regarded as
corrected when a discrepancy no longer exists between the two relevant input channels.
Activated
You can enable the corresponding channel for signal processing in the safety program.
If you disable a channel, channel diagnostics are no longer reported to the F-CPU for the
deactivated channel. Whenever you disable all output channels, you do not have to power
2L+ and 2L+ undervoltage reporting is suspended.
Input filters
The module filters the digital inputs to remove contact bounce and short duration noise. This
parameter assigns the duration of the filter time.
Channel failure acknowledge
Controls whether the channel is automatically reintegrated after a fault clears or requires an
acknowledgement (manual) in the user program. Refer to "Reactions to faults (Page 61)" for
the reintegration procedure.
Note
The configuration of the "F-Parameters": "Reintegration after channel fault" parameter can
determine your ability to modify the "Channel failure acknowledge" parameter's selection.
Sensor supply
You can assign whether to supply 24 V DC power to sensors from the module's integrated
sensor supply (internal) or from an external power supply (external).
Short-circuit tests are not performed for any channel where external power is selected.