Micromod Micro-PWC: 53PW6000 MicroPWC Configuration Guide - Manual (Page 320)

Micro-PWC CONFIGURATION GUIDE
300 Historical Block Data Collection
Click on the Computations button. The Historical Tag Computations window ( Figure 10-4 ) will be dis-
played.
The Historical Tag Computations window is composed of a matrix of toggle buttons which allow the user to
select individually the desired combinations of computation rate and computation type. Each row in the
matrix represents a computation rate; each column represents a computation type. By default, all buttons
are deselected and displayed in gray and appear raised. Click the toggle button which corresponds to the
desired computation rate and computation type. Selected buttons are displayed in yellow, and appear
pushed in.
Use the Number Retained text entry box at the end of each row to define the number of values to be
retained for each computation type selected for that computation rate. Once the retention limit has been
reached, the value obtained by each new computation will replace the oldest value. Because the retention
limit is defined on a per computation rate basis, it is not possible to set the Number Retained to a different
value for different computation types with the same computation rate. For example, it is not possible to set
a different Number Retained for the hourly/average and hourly/minimum values. However, it is possible to
configure different retention limits for hourly/average and daily/average values. Enter
inf (infinity) in the
Number Retained text entry box to retain all values collected; otherwise, enter a numeric value (zero is not
a valid numeric value). To retain no data for a particular computation type, all toggle buttons for the compu-
tation type must be deselected.
10.3.9 Configuring Multiple Historical Blocks
Once the configuration of an Historical Block is complete, click Apply. The current configuration session
will be saved, and the Historical Block Configuration window will remain open so that additional Historical
Blocks can be configured.
TS00218A
Figure 10-4. Historical Tag Computations Window
✎ Notes 1. No checks are performed to validate collection rate vs. computation rate. The
user must consider the collection rate of the data and take care to configure
appropriate computation rates; i.e., while it is technically feasible to perform hourly
computations on data which is collected once a day (daily), such a configuration
would result in many unnecessary and non-productive computations.
2. The amount of available disk space and the number, frequency and retention
rate of other collections on the system should be considered carefully when
configuring the retention time.