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Transmitting Commands to Devices from Access

Note: For a list of DDE commands, check out the support article listing WinWedge DDE Commands.

WinWedge makes it very easy for Excel to communicate with the device. This isn't limited to simply logging data from the device to Excel, but WinWedge also enables Excel to send data directly from VBA using WinWedge's SENDOUT and SEND DDE Commands

Sending a Command to the Device using SENDOUT DDE Command

The following code allows you to send any command to your device. In this example, we're sending four characters: an ASCII 27 (an ESC character), a capital 'P', and a carriage return and line feed characters (ASCII 13 and 10).

Function SendCommand()
   Dim Chan As Long
   Chan = DDEInitiate("WinWedge", "COM1")
   DDEExecute Chan, "[SENDOUT(27,'P',13,10)]"
   DDETerminate Chan
End Function

Sending a String to the Device using SEND DDE Command

If you need to send an entire string to the device, you can use the following code:

Function SendString (StringVar$)
   Dim Chan As Long
   Chan = DDEInitiate("WinWedge", "Com1")
   DDEExecute Chan, "[SEND(" + StringVar$ + ")]"
   DDETerminate Chan' terminate the link
End Function

This code can even be used to send an entire table or query out the serial port:

Sub SendQuery()
Dim chan, MyDb, MyQuery, strSend

'set database
Set MyDb = CurrentDb()

'open a table or query that holds the data you wish to send
Set MyQuery = MyDb.OpenRecordset("Deliveries")

'Open DDE Channel to WinWedge
chan = DDEInitiate("WinWedge", "COM2")

'point to first record in the table/query

strSend = "" 'reset string between records

'Generate string to send
For i = 0 To MyQuery.Fields.Count - 1
strSend = strSend & MyQuery.Fields(i) & ","

'trim off last comma and replace it with CR/LF
strSend = Left(strSend, Len(strSend) - 1) & vbCrLf

'send string
DDEExecute chan, "[SEND(" + strSend + ")]"

MyQuery.MoveNext 'point to next record in the query
Loop Until MyQuery.EOF 'while (we have not reached the end of the table/query)

'close DDE channel and clean up
DDETerminate chan
Set db = Nothing
Set chan = Nothing

End Sub

Categories: Macro / Code Sample, Microsoft Access, Data Collection, Serial (RS232), WinWedge

Last Updated: 2014.03.25

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