From the way that you’re writing to the sd card
EBD_STRING $ = “$ dtHT $ ftT $ et” + LAST_TIME $ + “$ st” + LASTTMS $
You’re grabbing data from the historical log and if you disable the historical logging (data stored locally on the Ewon) then you won’t be able to grab any data and write it to the SD card with your current script.
If you want to write historical logs to the SD card without having the logging enabled, you’ll need to do a good amount more scripting if you’re not going to be using the EBDs
As for how these tags are being logged though, you can either set them up for deadband logging (the value will log each time that the value changes by the value of the deadband)
ex:
if the deadband is set to 1, each time the tag value changes by at least 1, the value will be logged.
Another option is setting up a logging interval where it will log ever x seconds.
The last option is to setup the tags to log using the BASIC IDE and the function Logio.
The tags will only log if you have the “Historical logging Enabled” box checked off.