Downloading of the module parameters
The F-CM AS-i Safety ST then begins to read in code sequences of the safe AS-i slaves on
the connected AS-i bus. At the same time, the module downloads the module parameters
that were stored in the PLC CPU. The module parameters can only be downloaded when the
operating voltage is applied to the interface module of the ET 200SP and the parameters
have been made available by the PLC CPU during startup of the ET 200SP station.
The "Status" LED flashes green until the module parameters are completely downloaded or
the PLC CPU is in STOP state, or the PLC communication is interrupted.
Cyclic data exchange of safe input/output data
When a valid set of module parameters has been downloaded and the PLC CPU is in "RUN"
state, the safe input/output data is evaluated according the parameter assignment and
exchanged with the PLC CPU.
The PROFIsafe protocol is used for the data exchange.
The "Status" LED is lit green during cyclic data exchange.
If the F-CM AS-i Safety ST module starts cyclic data exchange directly after startup, but
communication cannot yet be established on the AS-i bus, the F-CM AS-i Safety ST module
supplies the substitute value "0" in the input image. Passivation is delayed by a maximum of
30 s in this case. As a result, communication can start on the AS-i bus within this time
window without passivation. After this time window, the input/output channels are passivated
if there is no AS-i communication.
Statuses not considered to be errors
The F-CM AS-i Safety ST module does not consider the following statuses to be errors, i.e.
no alarm and no passivation is triggered:
• Waiting for start-up test
• Input/output with value = 0 in the process image without error condition, e.g. normal
opening of the input contacts by pressing an emergency stop button or opening a
Diagnostic information can be read out in the user program using data records. For
information, please refer to Section "Data records for diagnostics (Page 57)".
Fail-safe Module F‑CM AS‑i Safety ST (3RK7136‑6SC00‑0BC1)
Manual, 03/2017, A5E03957059020A/RS-AB/002
3.2 Operating modes of the F-CM AS-i Safety ST