Trending/logging of data values has been part of the HMI
from the initial release. Trending was accomplished by storing data values, at
a user configured frequency (1 second or greater), to an internal database. The
“logged” data can be linked to a graphic trend element and displayed as a
scrolling trend. The data can also be exported to various formats.
Today we added a feature to allow a graphic trend element to
connect to a database, using ODBC, and fetch the stored data. An external
program can be used to store the data to the database or the HMI ODBC data
logger feature can be used. The ODBC data logger can store data at 100
millisecond or greater intervals.