Trigger – On Value Change Video at Inductive University

Transcript

(open in window)

[00:00] When using transaction groups, it is often useful to only have the group execute when values have changed. This might be any value in the group, or might be a specific tag or set of tags that you want to monitor. In transaction groups, there are multiple ways to accomplish this goal. All of which are configured on the trigger tab. So here we have a historical group with several integer values and a boolean value. The first and simplest method of restricting group execution would be to only log when any of the values have changed. This first option here does just that. Enabling the group in this mode will cause the group to execute the first time and then not execute again, until any of the values change. If we wanted to go further and restrict it to specific tags, we could change the mode from all tags to custom, and then select which tags allowed us to execute. For example, integer A or boolean A. Now the group will only execute, when either of those values change, it doesn't require that both of them change. Instead, it's an either or. The third way that we could configure the group would be to set a trigger on a specific tag, much like how we've done it other triggering videos. So for example, if we wanted to change on any change of integer C, we could select it and then select the active on value change. With this setting alone, the group would essentially act the same as if we had selected integer C in the on change condition above. However, both of these headings can be used together for finer grained control. So to summarize, in this particular configuration, we have selected integer a and boolean A in the top on change condition. And then down below, we've set integer C as our specific trigger condition. When use together, this means that the group will first look at these two values integer A and boolean A. And only when one of those have changed we'll look at integer C, if integer C has changed as well, the group will execute. So you see with all of these conditions combined, there's a great deal of flexibility in restricting group execution and logging only the data that you want to log.

When using transaction groups, it is often useful to only have the group execute when values have changed. This might be any value in the group, or might be a specific tag or set of tags that you want to monitor. In transaction groups, there are multiple ways to accomplish this goal. All of which are configured on the trigger tab. So here we have a historical group with several integer values and a boolean value. The first and simplest method of restricting group execution would be to only log when any of the values have changed. This first option here does just that. Enabling the group in this mode will cause the group to execute the first time and then not execute again, until any of the values change. If we wanted to go further and restrict it to specific tags, we could change the mode from all tags to custom, and then select which tags allowed us to execute. For example, integer A or boolean A. Now the group will only execute, when either of those values change, it doesn't require that both of them change. Instead, it's an either or. The third way that we could configure the group would be to set a trigger on a specific tag, much like how we've done it other triggering videos. So for example, if we wanted to change on any change of integer C, we could select it and then select the active on value change. With this setting alone, the group would essentially act the same as if we had selected integer C in the on change condition above. However, both of these headings can be used together for finer grained control. So to summarize, in this particular configuration, we have selected integer a and boolean A in the top on change condition. And then down below, we've set integer C as our specific trigger condition. When use together, this means that the group will first look at these two values integer A and boolean A. And only when one of those have changed we'll look at integer C, if integer C has changed as well, the group will execute. So you see with all of these conditions combined, there's a great deal of flexibility in restricting group execution and logging only the data that you want to log.

We are experiencing playback issues from our video hosting provider. Please check back shortly.

LESSON LIST

Take topic challenge