How can I change the logging interval for the DSC module?

[Brian_Beal]

I have logging set up for shared variables, but I don't need to log continuously.  Is there a way to change the logging interval?

[AdnanZ]

Hi Brian,

I hope you are doing well! When you say that you don't want to log continously, does this mean that you would like the shared variable to be logged in a fixed time interval of say 30 seconds? You should be aware that the DSC logs data everytime a tag value changes by an amount that is higher than the log deadband value you have defined for the tag in the Tag Configuration Editor. So, if that was your concern, then the DSC module does take care of that situation. Please be sure to let me know. More information can be found at
How to log data at different logging rate in LabVIEW DSC

[Brian_Beal]

Adnan-

That is exactly what I needed to know.  That is an efficient way of doing it.

Thanks,

Brian

[Brian_Beal]

It appears that the deadband is in percent instead of actual units.  Why is that?  I would prefer absolute units.

[AdnanZ]

Hi Brian,

I hope you are doing well! Deadband's, in terms of percentages, are more easier to program with. These links could provide more information:
What is a Deadband? What Types of Deadbands Exist? How are Deadbands Configured in OPC and the LabVI...
Deadbands and Scaling with Memory Tags in LabVIEW DSC

[Brian_Beal]

Thanks for the answer.  Yes, my project is coming along, and I think I am the backside of the learing curve for the DSC module. 

One more deadband question:  When configuring alarms, do I have to enable scaling for my variable for the deadband to work.  Since the alarm deadband is a percentage of full scale, what does it use for full scale if I don't have scaling enabled?

Thanks,

Brian

[AdnanZ]

Hi Brian,

I am glad your project is going well. You don't need to enable scaling in order for deadband to work. Deadband is just the the minimum percentage of a given range or amount by which a measured value must vary in order for the device or computer to register a change. If you enable scaling, then you need to set the deadband to reflect that.

[Brian_Beal]

Adnan-

My question regarding alarm deadband was whether or not I had to enable scaling.  The definition of alarm deadband is based on percentage of full scale range.  Without enabling scaling, what is the full scale range of the variable?  I understand the deadband for logging is a percentage change from the last logged value.

Brian

[Donald]

---

Brian Beal wrote:

My question regarding alarm deadband was whether or not I had to enable scaling.  The definition of alarm deadband is based on percentage of full scale range.  Without enabling scaling, what is the full scale range of the variable? ...

---

Unless this part of the DSC module has changed in newer versions:

Scaling does not have to be enabled, and the values used to define the full range are the default values of Raw Zero Scale and Raw Full Scale (on the Scaling page of the SharedVariable properties dialog) which are 0 and 100.