event detection scripting

[Matteo Cusmai]

Hi all,
can I set a datapoint trough Meta Data Point?

I have tried to set datapoint getting value from meta data point variable (my) but it seems no work.
This is the code:

LOG.fatal("before if: " + my.value);
p399.set('f');
return my.value;

Is it possible to manage this kind of logic?

Regards,
Matteo.

[phildunlap]

Hi Matteo,

No, only scripting data sources can call set(). In a scripting data source things like

p1.set(p2.value);

are supported. The trade off with scripts is that they execute on cron only, so once per second is the most often it will run.

If you need to use a single input to determine what to set a particular point, you can use a point link. The variable name for the source point is 'source' and simply "return" the value you wish the target to be set to.

[phildunlap]

...but you could use a meta point computing a value from multiple inputs, returning that as its value, and a point link using the meta point as a source and setting the target point.

Or you could put a 'set point' event handler on a change event detector on the meta point if it's a static value or the value of the meta point you need to set to the control point. There are lots of options.

[Matteo Cusmai]

Hi Phil,
Thanks for the quick answer.
There is some documentation about point links?

[phildunlap]

There is the help (?) within Mango for the Point Links and there are a couple examples around the forum: http://infiniteautomation.com/forum/search/"point link"?in=titlesposts&sortBy=timestamp&sortDirection=desc&showAs=posts