Trigger modules – Digital tab

Trigger properties

Trigger name and comment

In the trigger properties, you may enter a trigger name and comment.

Trigger parts

A trigger expression consists of one or several parts. Each part is an expression itself. With the OR function, these parts can be combined. Therefore, the trigger is 1 (TRUE) if one of its parts is 1 (TRUE).

The example in the figure above shows 2 parts: TriggerEdge([02:18],10,0,0.1) and TriggerLevel([0: 0],0.1,0).

The result:

If you want to add another trigger part, click the button showing the green plus symbol.

If you want to edit a trigger part, make sure that the part in question is selected. Consequently, all changes made in the settings below apply to this part.

If you want to remove a trigger part, click the button showing the red X symbol.

Trigger configuration tabs

Those expressions can be more or less complex, depending on the nature of the process or machinery. Five different trigger types are available for the most common situations.

• Edge

• Level

• Constant

• Change rate

• Custom

The characteristics of these trigger types are described in the table below. You will find the small drawings also in the dialog itself.

Trigger type	Explanation	Comment
Edge		Short trigger pulse duration after dead time.
Level		Short trigger pulse duration after dead time.
Constant		Duration of the trigger after dead time as long as the condition is fulfilled.
Change rate		Duration of the trigger after dead time as long as the condition is fulfilled.
Custom	Any logical expression or combination of trigger functions.	Full range of functions of the expression editor available. Note that the result must be a digital signal.

Example of the use of an expression for a user-defined trigger.

For information about how to use triggers as start or stop triggers for Data Storage refer to Trigger mode.