Xylem DH-21 - Manual (Page 67)

DH-21
Using the Graphical “W ATER LOG” Software 4-21
It is important to realize that the faster scan rate will not start until the sensor sees the change, so
some of the changing data at the first may be lost. Determine what losses are acceptable, and
what reporting times are needed to set up this mode of operation.
Again, note that this check is on the level parameter only, not the temperature, and the value
entered will be in the same units as set in the coefficients options. For example, if the coefficients
units are set to feet, the hyper limit will also be in feet.
4.4.3.4 Hyper-Delta Logging Mode Option
The Hyper-Delta Mode shown in Figure 4-12 is a combination of both the Hyper Mode and the
Delta Mode.
Logging Rate:
This is just like in the Linear Mode.
Delta Limit:
The Delta Limit sets the point that determines if the scanned data is to be logged or not.
Each time the sensor takes a reading, it will compute the absolute difference between this
reading and the last logged reading. If the difference between the new value and the last
logged value is less than the delta limit, the sensor will not log the new data. If the
difference between the scanned value and the last logged data is greater than the delta
limit, the new data will be logged.
Hyper Limit:
The Hyper Limit will be expressed in the units of measure specified under the conversion
options with inches, feet, meters, PSI, etc., being common units for this field. As long as
the difference between the current scanned level and the last logged level is less than this
set hyper limit, the scan rate will stay at the regular rate. If the difference is greater than
the set hyper limit, the scan rate will jump to a faster preset scan rate.
Hyper Divisor:
The Hyper Divisor is used to determine the faster scan rate. The faster scan rate is
calculated by taking the regular scan rate and dividing it by the hyper divisor. The hyper
divisor must be able to be divided into the regular scan rate without a remainder or it will
default to 1. For example, if the regular scan rate is 1 minute, the following hyper divisors
are valid: