Smithco Envizio Pro Installation & Operation Manual - Manual (Page 94)

Chapter 6
84 Envizio Pro and Envizio Pro II Installation and Operation Manual
Prescription Maps and Variable Rates
With the optional VRA feature enabled, the Envizio Pro or Envizio Pro II is capable of using a prescription map
to variable rate product application for a single product.
Envizio Pro or Envizio Pro II field computer uses the shapefile format for prescription maps used to provide
variable rate product control. If the variable rate feature is activated, a prescription map, created using GIS
(Geographic Information Systems) software capable of creating shapefiles, may be transferred to the field
computer. These shapefiles must be in a polygon shape format that complies with the ESRI (Environmental
Systems Research Institute) shapefile specifications and must also be in the WGS (World Geodetic System)
84 datum.
Shapefiles for prescription maps must be saved to the rxMaps folder to allow the field computer to locate and
save the required .shp, .shx and .dbf files to internal memory. Each of these files should be saved to the
rxMaps folder on the USB drive used to upload files to the field computer. Refer to the File Structure section on
page 143 for more information.
To ensure peak performance of the field computer during variable rate applications, create maps with the
minimum number of zones. Maps with too many zones may yield undesired results or limit performance of the
field computer. To help limit the number of zones within a map, use the equipment, or Guidance, width as a
guide. The smallest zones on the map should be no smaller than the width of the equipment applying the
product. For example, if the boom on a sprayer is 90 feet wide for each swath, zones within the prescription
map should not be less than 90 feet square.
If the prescription map contains zero rate zones, the system must have either a PWM or Fast valve controlling
product. The valve type and valve cal programmed on the field computer must be set to PWM Close or Fast
Close mode, depending upon which valve is installed in the system. See the Prescription (Rx) Settings section
on page 108 for additional prescription map set up information.
Note:
If the optional AccuBoom system is enabled, AccuBoom will turn off sections valves in zero rate
zones.
Loading Rx Maps
Prescription maps are loaded onto the field computer using the File Maintenance features described in the File
Maintenance section on page 128.
Prescription maps must have one .shp, .shx and .dbf file for each map. If any of these files are missing from the
rxMaps folder, the field computer will not be able to load the prescription map.
Note:
Names of prescription map files loaded on the field computer cannot begin with a space.