ProSoft Technology MVI46-DFNT - Manual (Page 139)

MVI46-DFNT ♦ SLC Platform Reference
EtherNet/IP Client/Server Communication Module User Manual
ProSoft Technology, Inc. Page 139 of 177
October 12, 2010
The C
OMMUNICATION D RIVER
should be set to the ETHIP driver. Make sure the
L OCAL
option is selected in the L
OCAL OR R EMOTE A DDRESSING
section of the
dialog box. You should not have to alter any data on this tab, as RSLinx knows
the communication path. Now click the A
PPLY
button to implement the options
and to establish the topic.
You are now ready to use the DDE link in a DDE client application. The following
example shows how to define a DDE link in an Excel Spreadsheet. It is also
possible to define a DDE link in a Visual Basic program. Any other Windows DDE
client application could be used including SoftLogix and RSSql.
Defining a DDE link in Excel
This is the simplest DDE link to define and should be used to make sure the
Topic is defined correctly before using more advanced applications. Before
attempting to make the link, verify that RSLinx is running and that the DFNT
module is seen. To make a DDE link in Excel, enter the application, topic and
item elements as a formula into a cell. The format for the formula is as follows:
=APPLICATION|TOPIC!ITEM
The "|" character (piping symbol) separates the application and topic fields and
the "!" (exclamation symbol) separates the topic and item fields. For our example
topic of ProLinx1, the entry into the cell is:
=RSLinx|CIP_Sample!'RealData[500]'
This causes the current value at the database double-word offset 500 (starting at
word address 1000) in the DFNT module to be displayed in the cell as a floating-
point value. This value updates at the frequency defined in the Topic
configuration in RSLinx. You can now place any database point in the DFNT
module using the same procedure in your work sheet. Note that the tag array
name is used for the item property and must be enclosed within the quote marks.
This is because the tag array name item reference looks like an Excel work sheet
reference. If you do not include the quotes, a formula error occurs. You can
select any of the defined tag array names defined in the module on your
spreadsheet.
When the items are used for the topic, RSLinx displays the following after
selecting the Active Topic/Items command on the DDE/OPC menu option:
Any DDE compliant program can be used in the same manner. For maximum
utility Visual Basic applications can be used to interface with module’s database
using DDE connectivity.