User manual

Using SIMATIC PCS 7 OSx @aGlance1-10
SIMATIC PCS 7 OSx 4.1.1 @aGlance
Using the SIMATIC PCS 7 OSx @aGlance Functions (continued)
Some clients read a null text string as no change and do not update the
value. For example, if the value of a TEXT tag changes from “Boiler 1 On” to
null (empty), then some clients see no change and continue to read the value
as “Boiler 1 On.” The
Null2Blank command replaces the null value with
blanks that these clients can read as a changed value. Whenever you intend
to request data from a TEXT tag for either a hot or a cold link, run the
Null2Blank command from the Command function first.
 ServerName — the prefix osx must appear in front of the OSx station
name.
 Command — enter the following:
null2blank
NOTE: Client_Login, Node_Roles,andNull2Blank are server-specific
extensions to the @aGlance
Command function. Refer to your client
documentation to determine how to send these commands to O Sx @aGlance.
To retrieve a list of tag names, your client must provide the server with the
following parameters.
 Server Name — the prefix osx must appear in front of the OSx station
name.
 Match String (optional) — enter a text search string. You can use the
standard wildcard * (match any) and ? (match single) characters.
 Start Index (optional) — enter an integer. The server uses the index as
a placeholder when there is more data to return than there are output
locations. A value of zero directs the server to return values starting at
the beginning of its database.
 Output — designate a location for the list of tag names.
 Tag Count — enter an integer that represents the number of entries in
the output.
Reading Null Text
Strings
Getting Tag Names