Hey, i have developed a custom app which uses a lot of direct .Write calls to the COM object, which in this case is a CLX driver. So when I do the .write is there any reason I can't just go back to back with them? Do I have to put a thread sleep in there? Is the .Write function ASync or Sync? Can I get some result verifying that the write was successful?
Here's my code for example where the HMI is controlling the process of the machine through writing of values. It's necessary this way unfortunately based on the machine design.
Public Sub RunUserProgram()
While Globals.CycleStart
Dim cmdComplete As Boolean = False
For i = 0 To MainMDIParent.childFormProgramEditor.MarkingOrder.Controls.Count - 1 'Ensures they're executed in the right order
For Each c As Control In MainMDIParent.childFormProgramEditor.MarkingOrder.Controls() 'Loop through every entity
Dim tempControl As EntityBaseClass = c
If tempControl.entityID = i And tempControl.EntityCheckState = CheckState.Checked Then
MainMDIParent.childFormProgramEditor.SetEntityBgColor(c, Color.LimeGreen)
If TypeOf c Is MoveEntity Then
ProcessMoveEntity:
Dim entity As MoveEntity = c
If entity.Axis = "X" Then
PLC.Write("cmdAxis", 1)
ElseIf entity.Axis = "Z" Then
PLC.Write("cmdAxis", 2)
ElseIf entity.Axis = "A" Then
PLC.Write("cmdAxis", 3)
End If
If Globals.loggingMode = Globals.LoggingModeSelection.Debug Then MainMDIParent.childFormMain.UpdateMachineActivity("Sending target data: " & entity.TargetPos)
PLC.Write("cmdTarget", entity.TargetPos) 'Send the Target Position to the PLC
Thread.Sleep(100)
Call MainMDIParent.childFormMain.UpdateMachineActivity("Verifying Command Position " & entity.Axis & ": " & entity.TargetPos)
'While Not verifyCmdPos(entity.TargetPos) And Not Globals.AbortActive
' System.Threading.Thread.Sleep(100)
' 'targetOK = verifyCmdPos(entity.TargetPos)
'End While
RetryVerifyTarget:
If Not verifyCmdPos(entity.TargetPos) Then
Dim resultDlg As Integer = MessageBox.Show("Failed to verify Taget Position data", "Data Transmit Failure", MessageBoxButtons.RetryCancel, MessageBoxIcon.Error)
If resultDlg = DialogResult.Retry Then
GoTo RetryVerifyTarget
Else
GoTo CancelOperation
End If
End If
Call MainMDIParent.childFormMain.UpdateMachineActivity("Moving " & entity.Axis & " to: " & entity.TargetPos)
PLC.Write("cmdMoveCommand", 1) 'Write the command down to the PLC to move
Thread.Sleep(100)
Call MainMDIParent.childFormMain.UpdateMachineActivity("Waiting for Move Done")
While Not verifyMoveDone(entity) 'Loop to check that the move is complete and axis is in position
If Globals.AbortActive Then GoTo CancelOperation
Thread.Sleep(100)
End While
Call MainMDIParent.childFormMain.UpdateMachineActivity("Target Move Completed")
ElseIf TypeOf c Is TriggerBurnEntity Then
Dim entiy As TriggerBurnEntity = c
Call MainMDIParent.childFormMain.UpdateMachineActivity("Triggering Laser")
PLC.Write("cmdLaserTrigger", 1)
Thread.Sleep(100)
ElseIf TypeOf c Is LoadProgramEntity Then
Dim entity As LoadProgramEntity = c
Call MainMDIParent.childFormMain.UpdateMachineActivity("Changing Laser Program to: " & entity.ProgramNumber)
PLC.Write("cmdProgramNumber", entity.ProgramNumber)
Thread.Sleep(100)
PLC.Write("cmdPrgChg", 1)
Thread.Sleep(100)
ElseIf TypeOf c Is LotNumberEntity Then
Dim entity As LotNumberEntity = c
Call MainMDIParent.childFormMain.UpdateMachineActivity("Updating Lot Number: " & MainMDIParent.childFormMain.tbLotNumber.Text)
PLC.Write("cmdLotNumber", Globals.LotNumber)
Thread.Sleep(100)
PLC.Write("cmdBlockNumber", entity.BlockNumber)
Thread.Sleep(100)
PLC.Write("cmdProgramNumber", entity.ProgramNumber)
Thread.Sleep(100)
PLC.Write("cmdLotChange", 1)
Thread.Sleep(100)
ElseIf TypeOf c Is ChangeMarkingStateEntity Then
Dim entity As ChangeMarkingStateEntity = c
entity.parseBlockValues(entity.BlockNumbers, entity.StateCommand)
System.Threading.Thread.Sleep(100)
Exit Sub 'Skip the command complete from PLC since we arent using it.
End If
End If
Next
Next
CancelOperation: 'TODO Insert code to handle an error
End While
End Sub
