Specifications

Main Properties
PlantScape Server and Client Configuration Guide 133
Note that, regardless of this “physical” rollover value, the accumulator point PV
continues to increase indefinitely until it reaches its maximum value or until it is
reset by an operator.
Range High Value
You also need to specify the value that represents the highest available range for
this point. This is only used to scale the height of the PV indicator.
Scale Factor
The scale factor is a multiplier (usually close to 1) that is used to convert the raw
counts of the totalizing device into engineering units. For example, if you are
measuring totals in megalitres, and the counting device uses 1 count to indicate 1
megalitre, the scale factor would be 1; if it uses 1 count to indicate 2 megalitres,
the scale factor would be 2.
Meter Factor
A meter factor is a multiplier that is used for calibration purposes.
Every time the controller’s counter value is scanned, the PV value is determined
by the following formula:
PVnew = PVold + ( SF × MF × Rawcounts )
Summary of Point Parameters and Addresses
The names of the parameters reflect their most common usage. They can,
however, be used to hold any controller values.
Because PlantScape can store and manage multiple values in the one point, you
can use a single point to monitor and control a complete loop.
Part Description
PVnew The new PV
PVold PV at the last scan
SF The scale factor
MF The meter factor
Rawcounts The change in the counter value since the last scan. If the new raw
count is less than the old raw count, the counter is assumed to have
rolled over.
plscpcg.book Page 133 Monday, May 28, 2001 10:11 AM