Echelon LNS DDE Server - Manual (Page 77)

Channel = DDEInitiate(Application, Topic)
Value = DDERequest(Channel, Item)
DDETerminate (Channel)
Following is a description of the parameters:
Application The DDE application as a string. By default, this is
“LNSDDE” for the LNS DDE Server.
Channel A DDE channel number created by the DDEInitiate()
function, as a long.
Item A DDE item as a string, as described in Specifying a Network
Variable earlier in this chapter.
Topic A DDE topic as a string. For network variables, this will be
an LMNV, DevNV, or NV topic as described in Topics in
Chapter 4 and in Specifying a Network Variable earlier in this
chapter.
Value The returned value from the one-time update request. This
will typically be assigned to a worksheet cell.
8. To return to Excel from the VBA editor, select Close and Return to Microsoft
Excel on the File menu.
9. To exit design mode and enable the ActiveX control, click Exit Design Mode on
the Control Toolbox.
Example
Private Sub btnReadSwitch4_Click()
Dim channel As Long
channel = DDEInitiate("LNSDDE", "LNS DDE Test.HVAC.LMNV")
Sheet1.Range("E21") = DDERequest(channel, _
"DI- 1.SW- 4.Digital.State")
DDETerminate (channel)
End Sub
Requesting a One-Time Network Variable Update Using
InTouch
The WWRequest function is used to request a one-time network variable update
using InTouch. To call this function, you must implement an InTouch action script
for each value to be requested. The action script will typically be called from an
InTouch button. To request a one-time network variable update using an InTouch
button, follow these steps:
1. Open an InTouch application project in WindowMaker and open the window that
will contain the button.
2. Click the Button tool on the Draw Object toolbar.
LNS DDE Server User's Guide 5-7