LogEnabled

[Jonansson]

What did you do in this line? What is the pupose of the LogEnabled command?

SETSYS TAG, “LogEnabled”,1

[Zach_HMS]

Hi Jonan,

The purpose of LogEnabled is to start the logging of the tag value.

reference:

Iterate List or Array of Strings within a Loop

If I have some conditional logic defined and the code I need to run within an IF block is just repeated commands, is it possible to define a list or an array of string values and then have a set of commands iterate through each value one after the other rather than duplicating code? I wasn’t sure if there were any gotchas with running a loop like this if possible within an IF block mattered or not but if so, I’m curious if this is possible if even just not within an IF block, if support could p…

[PJ_IOT]

@Jonansson

So as Zach says, setting that value to 1 means it is true that historical logging for that tag is enabled.

I used a combination of that technique and controlling or setting the deadband value accordingly per that logic to control the frequency of what level of change of a tag will log a new entry in the correlated tag’s historical log.

Typically we would have a control tag and based on it going to true per ONCHANGE I go to a function or routine that sets a tag to “LogEnabled” as true, and also set the deadband with some logic to set the incremental value of that tag for when it logs to the historical log file.

I’d have to look over some of the eWONs in production to give example logic but I’m not even certain I ever used this technique any after testing in production anywhere for the array list loop method.

If you can control the conditional at the PLC level of have sensors send signals if a trigger sensor of tag is true or not, that is always better and keeps the load off the eWON.

Having the conditional control this a the eWON level is however better than processing the data to a database and then cleaning it up and having conditional logic there.

Over the years, I have been able to fine tune data capturing at these levels to be as be optimized as possible so I like having all avenues in the toolbox to use as-needed as I’ve done all those scenarios before so that’s my perspective in a nutshell.