Siemens SIMATIC ET 200AL, System Manual

Page: 942 / 2255

Parameters/address space
4.4 Address space
Digital I/O module F-DI 4+F-DQ 2x24VDC/2A, 4xM12 (6ES7146-5FF00-0BA0)
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Equipment Manual, V1.0, 05/2021, A5E51082342-AA
A capacitive load that does not meet the load curve (see "Switching of loads (Page 86)") can
result in a passivation of the output in case of a process value change or switch-on test, even
if the dark test is disabled.
You can only reach up to SIL 2/Cat. 3/PL d with the dark test disabled.
WARNING
Loss of SIL 2/Cat. 3/PL d rating, loss of output control due to potential undetected faults
With the dark test disabled, an output that is turned on for more than 1 year may not be
able to be turned off.
SIL 2/Cat. 3/PL d requires that there is a signal change from "1" to "0" at the corresponding
output at least once a year.
Ensure the "0" signal has a duration of at least 2 seconds. It is not enough to simply turn off
the supply or load voltage of the F-module and turn it on again.
WARNING
Loss of cross-circuit detection between channels
When you use the function "Disable dark test", cross-circuits between channels with "1"
signal are not detected.
You must take this into consideration for your application and respective requirements of
your product standards.
You must also take into consideration the respective requirements of your product
standards regarding error detection time.
4.4 Address space
Note
The F-DI 4/F-DQ 2 Fail-Safe module uses more I and Q memory than required for the physical
number of inputs and outputs on the module. The extra bytes carry the PROFIsafe safety
status and data integrity information. The number of input (I) bytes and output (Q) bytes that
the F-DI 4/F-DQ 2 Fail-Safe module requires depends upon which PROFIsafe profile your fail-
safe CPU uses.
Module PROFIsafe profile Input (I) bytes
required
Output (Q) bytes
required
F-DI 4+F-DQ 2x24VDC/2A,
4xM12
V2.4 (with S7-300/S7-400) 7 5
V2.6 (with ET 200pro,
ET 200SP and S7-1200/1500)
8 6