Siemens SINUMERIK 840Di sl - Machine Trigger for PLC Timeout Trigger

12/2008 3 Setting up functions
3.4 Fault services
© Siemens AG 2008 All Rights Reserved
ePS Network Services, Function Manual (FH) - Release 12/2008
3-115
Field Content Type
Delete Deleting a comparison operation in the PLC
trigger does not result in the PLC variable
being deleted along with it, but instead
forces the variable to renounce its
participation at the trigger and hides the
logic operation.
If the forcing operation is undone by
selecting the variable again, the
comparison operation reappears as well.
SELECTION
Notice
If the next trigger is triggered before execution of the diagnostics actions is
completed (e.g. save data), the diagnostics actions, e.g. record data, cannot be
executed as parallel trigger evaluation is not possible. The missing of the trigger
and of course the data for this type of event cannot be prevented by the system.
The repeat frequency is generally less than one second, with high interface
demands it may be a few seconds.
3.4.6 Machine trigger for "PLC timeout trigger"
Description of functions
The Timeout Trigger offers the possibility to monitor actions and functions which
could not take place in the time window intended or specified for them.
The real time difference which triggers the trigger if exceeded by the time
configured here for comparison is determined with a definable start and stop signal
from the PLC. The trigger can trigger all actions available in the control monitor.
The same variable or different variables can be used as start and stop signal. All
relational operators permissible for the PLC variables can also be used.
Notice
The logical evaluation whether the timeout value is exceeded, is time-delayed by
the system. This must be taken into account if actions that can only capture
realtime data are triggered by the timeout trigger. It is not possible to capture
precisely timed data from the cycle in which the timeout took place (max. delay in
the minute range).
Due to system dependencies, repeatability of the timeout function is also linked to
the communication runtimes which depend on the demands placed on the
interface between PLC and PC of the operator. As a rule, repetitions of less than
one second can be achieved; with high interface demands it may however be a
few seconds.