system.tag.read

Description

Reads the value of the tag at the given tag path. Returns a qualified value object. You can read the value, quality, and timestamp from this object. If the tag path does not specify a tag property, then the Value property is assumed.

Syntax

system.tag.read(tagPath)

Parameters

String tagPath - Reads from the given tag path. If no property is specified in the path, the Value property is assumed.

Returns

QualifiedValue - A qualified value. This object has three sub-members: value, quality, and timestamp.

Scope

All

Examples

This example would read a value and display it in a message box.

qv = system.tag.read("[]EastSection/ValveG/HOA_bit")

system.gui.messageBox("The value is %d" % qv.value)

This example would check the quality of a tag value, and write it to the database if the quality is good

qv = system.tag.read("[]EastSection/ValveG/HOA_bit")

if qv.quality.isGood():

   system.db.runPrepQuery("INSERT INTO VALVE_TABLE (HOA) VALUES (?)", qv.value)