Operating mode during start-up (warmstart)
The response of the positioner to the warmstart is determined by the parameter
FSAFE_TYPE (fail-safe action).
If FSAFE_TYPE is set to "adjust to fail-safe value", the positioner switches to automatic opera-
ting mode and adjusts to the value determined by the parameter FSAFE_VALUE.
If FSAFE_TYPE is set to "adjust to last set point value" or "fail-safe position determined by
spring action", the device remains in fail-safe position. As soon as a valid set point SP is
transmitted to the positioner, the operating mode changes to automatic.
If the status of the transmitted set point is "bad" or the positioner has not been successfully in-
itialized, it remains in fail-safe position (out of service) in K1.51 version. In K1.6 and higher,
the behavior for a BAD set point status is determined by the FSAFE_TYPE parameter.
Monitoring parameters FSAFE_TIME, FSAFE_TYPE, FSAFE _VALUE
The action determined by the FSAFE_TYPE (fail-safe action) parameter is triggered by the fol-
lowing events:
Start-up of the positioner (warmstart)
Elapsing of the DP watchdog through interruption of the cyclic communication with a Mas-
ter Class 1 (not applicable, when communication is terminated properly).
Elapsing of FSAFE_TIME in Automatic or Remote Cascade operating mode, when the
status of the reference variable, SP or RCAS_IN, valid in this operating mode is set to "in-
itiate fail-safe".
Receipt of a DP-"Global Control" service for which the clear bit is set (not yet applicable
for version K 1.30).
By setting the status of the reference variable used in the valid operating mode to "bad", the
actuator always moves to the fail-safe position determined by the spring action (for firmware
version K 1.30 to K1.51). In version K1.6 and higher, the behavior for a BAD set point
status is determined by the FSAFE_TYPE parameter.
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EB 8382-1 EN
How to implement the PROFIBUS Master Class 1
Summary of Contents for 3785 series
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