LOCAL TAG is a user defined local screen tag used within a Graphic Display. Local Screen Tags show up using the VIEWDAQ button of the Point List. Local screen tags are commonly used to animate displays or hold temporary values.
When a User creates a Local Tag File in the Graphics Builder and assigns the Local Tag File to a graphic display. Tags are created with Span Hi, Span Lo and engineering units. Local Tags do not alarm. Users can define the security Level required to change tags. A user must have a level equal to or greater than the Local Screen Tags level.
A common example of Local Tags is a screen tag to animate a spinning fan. Script increments the local tag from 0 to 360 based on the On/OFF state of a digital IO tag.
VIEW TAG is a predefined screen tag also referred to as a "system tag" or "ViewDAQ Tag".
View Tags describe time, date, alarm logs etc (for example %AALMGLOBAL) they show up using the VIEWDAQ button of the Point List. All View Tags begin with the percent sign (%). %A is an analog type, %D is a digital type and %T is a text type. Some View Tags are assigned Level 255 and are READ only.
A user can be assigned the ability to change these tags if he is assigned level 127 (for example View Tag = 127) and the View Tag is not read only.
Setting a users Level = 127 for VIEW TAG, enables him to change the ALL View tags. To users enable users to change only some View Tags, consider using a script or keymacro assigned to a pushbutton.
Pushbutton Keymacros and screen scripts can change most View Tags, regardless of the user's security Area and Level.