Describes the intended maximum value of the tag. Depending on how the tag was built, this might be the true maximum value or just an indication.
Span Lo is used by some Scaling Types to "re-scale" the value read from the PLC. For some Scale Types, Span Lo is the minimum value of the Tag. For other, Scale Types, SpanLo is for Display Use only. For example, if No Scale is selected, the SpanLo appears on Trends and Displays, but is informational only. The actual value can exceed Span Lo if no scale is used. (See Scaling Type for more details).
Span Lo is used by Trends, Overviews, and user built animation to determine the Minimum Value of the Tag. For example, if a tank is filled by a Tag, the Span Lo is used to determine the tag' value for an empty Tank. This field is for ANALOG tags and parameters only.
-99,999,999,99 to 99,999,999,999
Field Type: analog
Configuration: Span Low
Tag field: .SPANLO