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Syntax for dde addresses, Scanning for new tag values – Rockwell Automation FactoryTalk View Site Edition Users Guide User Manual

Page 659

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B

S

ETTING

UP

DDE

COMMUNICATIONS

FOR

HMI

TAGS

B–3

• •

B • Pl

aceh

old
er

2. In the Address box, specify the DDE item.

Type the DDE address for the tag. The DDE item name and format depend on the
DDE server, and are not validated by FactoryTalk View.

Syntax for DDE addresses

The syntax for DDE tag addresses is:

DDE : Application|Topic!Item

There are no spaces:

Between the application name, the vertical bar, and the topic name.

Between the topic name, the exclamation mark, and the item name.

For more information about addressing syntax, see the documentation supplied with the
DDE server.

Scanning for new tag values

When an HMI server containing tags is running, it must periodically update its tag values
in the value table.

For applications using DDE, values are updated by the server at the rate specified in the
server product. When the server detects a change, it provides the changed value to
FactoryTalk View.

For details about setting the poll rate, see the server documentation.