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IOServer DDE interface

Application Name


Topic Name

Any Topic Name will be accepted as valid. Should allocate a topic for each device.

Update Rate

The initial update rate of all Topics is IOServer Preferences->DDE Settings->Update Rate. The update of each Topic can be individually set by writing to IOSDDE|TOPIC!UPDATERATE. e.g. Poking 100 to IOSDDE|RTU12!UPDATERATE will set the update rate for Topic "RTU12" to 100ms.

Using IOServer with Excel

To display a 10x10 array from the Modbus Device 'Master'.

1. Select a 10 by 10 area.

2. Type in


3. Press Ctrl-Shift-Enter


Example of a function to write the value at worksheet OPC.A4 to "Master.40001"

Sub TagWrite()
Dim rangeToPoke
Dim channel
channel = Application.DDEInitiate("IOSDDE", "Group")
Set valueToPoke = Worksheets("OPC").Range("A4")
Application.DDEPoke channel, "Master.40001", valueToPoke
Application.DDETerminate channel
End Sub

Using NetDDE from Excel in Windows 2000/XP/NT4

Server Configuration

1. Run %SystemRoot%System32\ddeshare.exe on the computer on which IOServer is running.

2. Add a share in the Shares.DDE Shares.


3. Set Trusted Share Properties in Shares.Trusted Shares.


4. Load mbtcp.io into IOServer.

Client Configuration

Enter the following into a cell in Excel

Where Gateway is the DDE Server Machine name


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Last updated: Mon, 01 Feb 2021 12:47:46 GMT