VB 6.0 Send Data Example

Impact AIT
Visual Basic 6.0 Edition

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›Data Exchange - TCPIP - VB6
›Data Exchange - TCPIP - VB6 - Receive Data

Transfer data to and from a Datalogic device

Notes: The default AIT root distribution folder for this application is: /Datalogic/IMPACT/AIT/Data Exchange/TCPIP

Note: If you receive the following error message when you attempt to run any of the included sample files,
Component 'MSWINSCK.OCX' or one of its dependencies not correctly registered: a file is missing or invalid
you need to install the Visual Basic 6.0 Run-time Files that include the file MSWINSCK.OCX.

Part 2 – Create a listener to receive data from the device

Modify the vision program
Modify the Visual Basic Project

Modify the vision program created in Part 1 (Go to Part 1)

1. Start VPM and open the vision program file modified in Part 1 (Light Bulb Inspection TCPIP.vp). (Note: The completed sample program is in the AIT distribution subfolder /VisualBasic6/Example1/IMPACT Files/Light Bulb Inspection TCPIP.vp.)

2. Add a new task to the program and rename it to Send TCPIP Message.

3. Select None for the trigger event. See example

4. Add a TCP/IP Out tool from the Data tool group.

5. Select the task and click the Add Input button. In the TCP/IP Out tool, select the Input String property. This will promote the tool's property to a task input. See example

6. Select the TCPIP Event Received task.

7. Steps 8 through 10 will set up a Data Tool to send the parsed incoming IP address into a TCP/IP Out tool so a response can be sent to the correct Datalogic device.

8. Add a Data Set tool (from the Data tool group) after the Basic tool named Parse Incoming String.

9. Set the Data Set tool's Data Type to String and rename it to Change IP Address.

10. Click the Create Patch icon in the Data Set tool's value property. In the Basic tool (Parse Incoming String) select the property named ip_address_string. See example

11. Click the Create Patch icon in the Change IP Address Data Set tool's Destination Port property. Select the task tab named Send TCP/IP Message. In the TCP/IP Out tool, select the property named IP Address. See example

12. Steps 12 through 14 will set up a Data Tool to send the parsed incoming Port Number into a TCP/IP Out tool so a response can be sent to the correct device port.

13. Add a Data Set tool (from the Data tool group) below the first Data Set tool. Set the tool's Data Type to Integer and rename it to Change Port Number. See example

14. Click the Create Patch icon in the Change Port Number Data Set tool's property value. In the Basic tool (Parse Incoming String) select the property named port_number_int. See example

15. Click the Create Patch icon in the Data Set tool's Destination Port property. Select the task tab named Send TCP/IP Message. In the TCP/IP Out tool, select the property named Port Number. See example

16. Add a Call Task tool from the Programming tool group below the second Data Set tool (named Change Port Number). Rename it to Send Response Message.

17. In the Call Task tool's Task value field, select Light Bulb Inspection TCPIP.Send TCPIP Message from the drop down list. See example

18. In the Call Task tool's Input String value field, enter the string "This is the response message" without the quotes. This string will be sent back to the received IP address and Port Number.

19. Save the file and unlock VPM. Click the online/offline button in VPM to put the device online.

Modify the Visual Basic project created in Part 1 (Go to Part 1)

1. Start Microsoft Visual Basic 6.0. (Note: This sample code is in the AIT distribution subfolder /VisualBasic6/Example1/Project.)

2. From the project explorer, select the project Impact_TCPIP.

3. Add a new Winsock control to the form and rename it to Data From Device.

4. Add a new label control to the form and rename it to Received_Data.

5. Delete the value in Received_Data’s caption.

6. Double click on the form and replace all existing code with the following code. (You may select and copy the code from this page.)

Private Sub Connect_Click()
  'Set the IP address and port number of the Datalogic device
   Data_To_Device.Close
   Data_To_Device.RemoteHost = IPAddress.Text
   Data_To_Device.RemotePort = CInt(PortNumber.Text)
   'The device has to be online before it can receive any TCPIP events
     If Data_To_Device.State = sckClosed Then
        Data_To_Device.Connect
     End If
End Sub
Private Sub Data_To_Device_Connect()
     'Send IP Address and port number information to the device
     Data_To_Device.SendData Data_To_Device.LocalIP & "," & Data_From_Device.LocalPort & vbCrLf
End Sub
Private Sub Form_Load()
     'Set the local port number to listen on
     Data_From_Device.LocalPort = 5150
     'Display the IP address and port number of this PC
     Me.Caption = "Local IP Address = " & Data_To_Device.LocalIP & ", Port Number = " & Data_From_Device.LocalPort
     'Start listening for data
     Data_From_Device.Listen
End Sub
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
     'Close the ports
     Data_To_Device.Close
     Data_From_Device.Close
End Sub
Private Sub Data_From_Device_ConnectionRequest(ByVal requestID As Long)
     'A connection request had been received, close the port and accept the connection
     If Data_From_Device.State <> skclosed Then
      Data_From_Device.Close
     End If
     Data_From_Device.Accept requestID
End Sub
Private Sub Data_From_Device_DataArrival(ByVal bytesTotal As Long)
     Dim strData As String
     'Extract the incoming data
     Data_From_Device.GetData strData
     Received_Data.Caption = strData
End Sub

7. Save the project.

8. Make an executable file from the project then run the executable. What does the program User Interface look like?

When you click the Connect button, the Visual Basic program sends the displayed IP Address and Port Number to the Datalogic device. When the device receives the TCPIP message, it runs the TCPIP Event Received task in the vision program Light Bulb Inspection TCPIP.

The TCPIP Event Received task sets the IP Address and Port Number on the TCP/IP Out tool to what was received, then runs the TCP/IP Out tool. This sends the message contained in the tool's Input String property back to the Visual Basic program. This program is listening on the displayed port for a response. When the message is received, the Visual Basic program extracts the message string and displays it in the Caption field of the Received_Data label control.