Configuration
4.9 Data points
4.9.8
"Trigger" tab
Trigger
Data points are configured as a static value or as an event using the "Type of transmission"
parameter:
Saving the value of a data point configured as an event
Saving the value of a data point configured as an event in the send buffer (message
memory) can be triggered by various trigger types:
● Threshold value trigger
The value of the data point is saved when this reaches a certain threshold. The threshold
is calculated as the difference compared with the last stored value, refer to the section
Threshold value trigger (Page 79).
● Time trigger
The value of the data point is saved at configurable intervals or at a specific time of day.
● Event trigger (Trigger tag)
The value of the data point is saved when a configurable trigger signal is fired. For the
trigger signal, the edge change (0 → 1) of a trigger tag is evaluated that is set by the user
program. When necessary, a separate trigger tag can be configured for each data point.
Resetting the trigger tag in the bit memory area / DB:
If the memory area of a trigger tag is in the bit memory or in a data block, the CP resets
the trigger variable itself to 0 (zero) as soon as the value of the data point has been
transferred. This can take up to 500 milliseconds.
Note
Fast setting of triggers
Triggers must not be set faster than a minimum interval of 500 milliseconds. This also
applies to hardware triggers (input area).
Note
Hardware trigger
You need to reset hardware triggers via the user program
Transferring the value of a data point configured as an event
You specify whether the value of a data point is transferred to the communications partner
immediately after the trigger fires or after a delay in the "Transmission mode" parameter.
Transmission mode
The transmission mode of a frame is set in the "Trigger" tab of the data point. With the
option, you specify whether messages of events are sent immediately or following a delay:
● Immediate transfer - Spontaneous
The value is transferred immediately.
78
Operating Instructions, 12/2016, C79000-G8976-C365-02
CP 1243-1