The tag elements which have read/write access can be modified. However, these elements can only be updated as a whole; writes to an individual element item is not allowed.
The following table shows the result of writing to each of the tag elements:
|Element Name||Write allowed||Write Result|
|Not specified (unqualified tag reference)||Yes||Write to the Field element and propagate the value to the I/O Device.|
|Field||Yes||Write to the Field element and propagate the value to the I/O Device.|
|Valid||No||Will not succeed|
|Override||Yes||Write to the Override element|
Write to the Override Mode element.
See the appropriate function references for the available override mode values.
Note: When the tag is in Override mode, an unqualified tag reference will refer to the Override element
Write to the Control Mode element
The Value item can be one of the following:
0 – Control inhibit mode is Off.
1 – Control inhibit mode is On.
Note: When Control inhibit mode is On, writing to the Field element is prohibited.
|Tag Status||No||Will not succeed|
If you determine that the tag value is incorrect because of a sensor or communication interuption, the tag value may need to be overridden. The Override element tag element is used to store the overridden tag value. For further information refer to Controlling and Overriding Tag Values.