4.2.24         Span Lo

This value appears on displays, trend and dialog boxes describing the intended maximum value of the tag.  For some Scaling Types, this is a hard limit. For No Scale and other scaling types, it is an indication only that may be ignored

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, Span Lo is for Display Use only.   For example, if No Scale is selected, the Span Lo 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.

Range:                    -99,999,999,99 to 99,999,999,999
Field Type:            analog
Tag field:               .SPANLO