Reference Manual
748384-C
September 2003
Rosemount Analytical Inc. A Division of Emerson Process Management
Introduction 1-35
NGA2000 Reference
c. Troubleshooting
I only get one data point…
You probably are not writing the
DATA_INDEX correctly. Verify that this
variable is indeed being written. Excel does
not tell you if it has failed to poke a value.
Common reasons for this include having the
wrong network address, trying to poke a
variable or a value, rather than a spread-
sheet cell address, or a typo in the variable
name.
You may also not be waiting long enough
for the analyzer to respond. In the Excel
example above, the macro writes
DATA_INDEX, then reads DATA_POINT
and does so repetitively until the index re-
ported in this variable is the same as that
requested.
I get lots of data, but it has a discontinu-
ity in it…
The time rolls over after 24 hours. Each
point is stored at a particular segment of
memory, overwriting the point stored 24
hours earlier. So if you read the points from
1 to 96, somewhere the day will switch from
today to 24 hours ago.
Use the reported time cell to sort the data
so it is an appropriate order.
The data seems to be full of garbage…
The analyzer stores internal data in volatile
memory. If there is loss of power, this
memory is reset. When this happens, the
internal storage is set to nonsense values,
and the analyzer starts recording data in the
area in the memory appropriate to the time
of day, if it knows what that is from a net-
work update. Only the section of memory
that has been filled since the power failure
will have any meaningful data in it.
