Echelon LNS DDE Server - Manual (Page 76)

The Al- 1.Node Object 0.Node_Directory item would be reformatted as a
UNVT_u_long, by using the -t option as follows:
Al- 1. Node Object 0.Node_Directory –t#8011223344556677[1].UNVT_u_long
This item specifies the AI- 1 device, the Node Object 0 L
ON M ARK object, and the
Node_Directory network variable member of the L ON M ARK object. The format is
specified as the format defined for program ID 8011223344556677, with a selector of
1, and a format name of UNVT_u_long.
Requesting a One-Time Network Variable Update
To request a one-time update, your client application sends a DDE Request message
to the LNS DDE Server. The LNS DDE Server responds with the requested value.
The format of the request is application dependent. The following sections describe
how to request a one-time update in Excel and InTouch.
Requesting a One-Time Network Variable Update Using Excel
Three separate functions are required to request a one-time network variable update
using Excel. They are the Excel DDEInitiate(), DDERequest(), and DDETerminate()
functions. To call these functions, you must implement a Visual Basic for
Applications (VBA) macro for each value to be requested. VBA is included with
Excel.
The request macro will typically be called from an ActiveX control such as a button.
To request a one-time network variable update using an Excel button control, follow
these steps:
1. Create or open an Excel spreadsheet and select the worksheet that will contain
the button.
2. If the Control Toolbox is not displayed, point to Toolbars on the View menu, and
then select Control Toolbox.
3. Click the Command Button control on the Control Toolbox.
4. On the worksheet, drag the control to the size you want.
5. To set the properties for the control, right-click the control, and then select
Properties on the shortcut menu.
6. To add VBA macro code to the control, right-click the control, and then select
View Code on the shortcut menu. The VBA editor will be opened, and a new VBA
function will be created for your button code.
7. Enter the following code:
Dim Channel As Long
5-6 Reading and Writing Network Variables