User Documentation

Data recorder
System manual
2696790000/02/04.2020
87
Information
If manual recording is selected for a profile, note that calls from DataRe-
cApiSampleValues are not only necessary for data recording, but also for
state transformations in the profile. For automatic recording, the calls and
the state transformations associated with them are made by the configured
task. This must be implemented in the application for recording manually.
For example, a call from DataRecApiSampleValues involves the following
additional steps, which can cause a state change from waiting to record-
ing:
● Testing of a configured start-trigger condition for their occurrence
● Testing for the expiration of a start delay set with DataRecApiSetRec-
Count
Furthermore, in the case of the SingleShot buffer type, DataRecApiSample-
Values causes a state change from recording to stopped when the end of
the buffer is reached.
The recording mode (standard or change-based) of a profile can be config-
ured using the DataRecApiSetRecMode function. In the change-based
mode, the tolerance value can then be changed using DataRecApiSetVar-
Tolerance or enabled using DataRecApiRemoveVarTolerance.
Information
In the change-based modes, note that a profile only detects changes of
variable values in the course of the call from DataRecApiSampleValues.
Writing the application to the monitored variable alone does not cause any
recordings!
Using the DataRecApiSetRecCount function, the following limitations can be
set:
● Start delay: Number of calls by DataRecApiSampleValues after the start
of recording, which do not generate any recordings, but instead imple-
ment a countdown for the recording.
● Number of the recordings to be stored: Number of calls by DataRe-
cApiSampleValues (without start delay) until the automatic recording
stop.
Special case in the change-based recording mode with a monitored variable:
The mere number of calls from by DataRecApiSampleValues is not a part of
the number of recordings to be stored, since not every call needs to be
stored. Instead, only the actual recording calls of the function are those
which count. In the remaining modes, by contrast, the pure calls to DataRe-
cApiSampleValues do count.
You can set a trigger using DataRecApiSetTrigger and rescind it again us-
ing DataRecApiRemoveTrigger.