Using Standard VB objects with HMI

[Jesse]

Is it possible to use a standard combo box and have it send values to different locations such as different N files depending on what option the operator selects, and I'm pretty new to coding so if it is what would that look like?

[Archie]

Yes. Sometimes it involves a bit of coding. In the Tips & Tricks section is a short tutorial on turning a standard windows control into an AdvancedHMI control.

[Jesse]

Ok so I have my Combobox made and I have a 3 "items" in it. I used the code from a basic label for it and in the properties its has PLCaddress, value, keypad etc.
Now all my experience is with PLCs I have barley any with structured text. My 3 Items are Heat, Soak, and Carbon. If you could show me the code that would give me a properties option of PLCaddressHeat I think I could figure out the rest.
 
Thanks.

[Archie]

Do you want the control to write the values to the PLC when the selection is changed, or do you want it to read from the PLC and update the value based on what it read from the PLC?

[Jesse]

If the operator selects the item heat I will need the textbox to pop up where operator will enter a number it will then write that value to an N file
at the same time when heat is selected it needs to also write a 3 to another N file

The 3 will be a constant it will never change.

[Jesse]

or instead of a plcaddressheat option could you should me the code that would be like..

If Combobox1.text = "heat" Then


       TextBox1.Visible = True
      ' here is the part I don't know how to do (sending a value to slc/clx)
 Else
       TextBox1.Visible = False
       '........

End If

[Archie]

If Combobox1.text = "heat" Then
       TextBox1.Visible = True
      ' here is the part I don't know how to do (sending a value to slc/clx)
 Else
       TextBox1.Visible = False
       '........
End If

EthernetIPforCLXCom1.Write("MyTag",3)

or

EthernetIPforPLCSLCMicroCom1.Write("N7:0",3)

[Jesse]

Works just like I was hoping for, Thank you! you made a great program!

[Jesse]

I apologize in advance for asking so many questions, but as i said I'm new at VB programing.

Heres the deal: in the image I attached to this there are 40 comboboxes and 40 text boxes and each line represents a step so there for instance line 1 has a label step one then a combobox then a text box, so 40 lines, in each text box there will be 13 items (heat, soak, ramp, .. etc.) dependend on what step it is and on what item was selected it is going to send a value 1-13 (heat= 1, soak = 2, ramp = 3, etc.) to an N file N20[0] through N20[39] (step 1 = n20[0], step 2= n20[1], etc.).

And on top of that the value of the text box will be sent to a F file corresponding to it's step so (step 1 textbox.text = F21[0], and so on..)

Once the operator has entered in all of these items and values they will click the send to PLC button. Now I wrote a piece of code to test it and it worked with an If statement.

That code is only for the first step and there are 40 and doing this with an if statement just seems like the wrong way of doing it to me because its going to be so long and messy. So I was wondering if you could put me on the right track of writing this code if you know of a better way?

Thanks.

Private Sub btnPLC_Click(sender As System.Object, e As System.EventArgs) Handles btnPLC.Click

        If OpCodeBox1.Text = "HEAT" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 1)
        ElseIf OpCodeBox1.Text = "CARBON" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 2)
        ElseIf OpCodeBox1.Text = "NULL OPCODE" Then
            EthernetIPforCLXCom1.Write("F21[0]", 0)
            EthernetIPforCLXCom1.Write("N20[0]", 0)
        ElseIf OpCodeBox1.Text = "RAMP" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 3)
        ElseIf OpCodeBox1.Text = "SOAK" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 4)
        ElseIf OpCodeBox1.Text = "TEMP LIMIT TIME" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 5)
        ElseIf OpCodeBox1.Text = "CARBON LIMIT TIME" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 6)
        ElseIf OpCodeBox1.Text = "AMMONIA EVEN" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 7)
        ElseIf OpCodeBox1.Text = "END OF CYCLE EVENT" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]",
        ElseIf OpCodeBox1.Text = "SPARE EVENT" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 9)
        ElseIf OpCodeBox1.Text = "PROBE BURNOFF EVEN" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 10)
        ElseIf OpCodeBox1.Text = "TEMP DEVIATION" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 11)
        ElseIf OpCodeBox1.Text = "CARBON DEVIATION" Then
            EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)
            EthernetIPforCLXCom1.Write("N20[0]", 12)
        End If
    End Sub

[Archie]

How about something like this.... In your drop down boxes put a value in parentheses after the text

HEAT (1)
CARBON (2)
NULL OPCode (0)

Then extract that value to write to PLC. Your code always writes OpText1.Text to F21[0], so that line only needs to be there once.

Code: [Select]

Dim ValueToWrite as integer
Dim StartOfValue As Integer = ComboBox1.Text.LastIndexOf("(") + 1
Dim LengthOfValue As Integer = ComboBox1.Text.LastIndexOf(")") - StartOfValue
ValueToWrite = CInt(ComboBox1.Text.Substring(StartOfValue, LengthOfValue))
EthernetIPforCLXCom1.Write("N20[0]", ValueToWrite)
EthernetIPforCLXCom1.Write("F21[0]", OpText1.Text)


[Jesse]

Thank you, took me a little bit of research to see what you're doing there but I figured it out, that will probably work though 2 of my items are actually going to have numbers in parenthesis already but I don't think it would cause a problem, is there possibly another solution though?

[Archie]

You can get a little more advanced and populate the combobox in code and use a dictionary collection to cross reference the integer value to the string:

Code: [Select]

'* Declare a class scope dictionary object
    Private d As New Dictionary(Of String, Integer)

'*** Double click a blank spot on the form to get to this load event
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        d.Add("Null OpCode", 0)
        d.Add("Heat", 1)
        d.Add("Carbon", 2)

        For Each item In d
            ComboBox1.Items.Add(item.Key)
        Next
    End Sub

'* When the button is clicked, look up in the dictionary collection (d)
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        EthernetIPforCLXCom1.Write("N20[0]",  CStr(d(ComboBox1.Text)))
    End Sub


[Jesse]

So I decided to go with the dictionary way. It works really well and saved me a lot of code, although there's still something I'm not sure how to do now. Sorry this VB has really been a learning curve for me. But if the operator/user ever selects NULL OPCODE in a combobox that will be the last step and after that the rest of the comboboxes and text boxes will just be blank and i plan for their visibility to go false and the N and F files that they're linked to, to receive values of zero. How would I go about that? I tried if statements for the visibility but then the blank combos only go invisible if you try to change the index.

[Archie]

This is once again an advanced technique that will seem overwhelming until you get a very good understanding of .NET, never the less it is more compact than brute forcing it.

The code takes advantage of the Tag property, which is a general purpose property only there for the programmers use. First you must go into each ComboBox on the form and set a value in the Tag property to tell the code which order they are in (1,2,3,...). This also build on the dictionary lookup code from above. I tried to comment it in detail to help you understand how it works.

Code: [Select]

   '* After the next line, add the full list of comboboxes on your form so this event will fire when any of them are changed
    Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged, ComboBox2.SelectedIndexChanged, ComboBox3.SelectedIndexChanged
        '* First we must find the lowest Tag value of the box with a null value selected
        Dim NullBoxTagValue As Integer = 9999
        '* Go through each control on the form
        For Each ControlOnForm As Control In Me.Controls
            '* only process comboboxes with something in the Tag property
            If TypeOf (ControlOnForm) Is ComboBox Then
                If ControlOnForm.Tag <> "" Then
                    '* Did we find a ComboBox with a value of null?
                    If ControlOnForm.Text <> "" AndAlso d(ControlOnForm.Text) = 0 Then
                        '* is this Tag value less than what we already found?
                        If ControlOnForm.Tag < NullBoxTagValue Then
                            NullBoxTagValue = ControlOnForm.Tag
                        End If
                    End If
                End If
            End If
        Next

        '* Now we can go through and enable/disable boxes that are higher than the null
        For Each ControlOnForm As Control In Me.Controls
            '* only process comboboxes with something in the Tag property
            If TypeOf (ControlOnForm) Is ComboBox AndAlso ControlOnForm.Tag <> "" Then
                '* If we are greater than the null box, then disable
                If ControlOnForm.Tag > NullBoxTagValue Then
                    ControlOnForm.Text = ""
                    ControlOnForm.Enabled = False
                Else
                    ControlOnForm.Enabled = True
                End If
            End If
        Next
    End Sub


[Jesse]

So I used your code except changed one thing:

If ControlOnForm.Text <> "" AndAlso d(ControlOnForm.Text) = 0 Then
If ControlOnForm.Text <> "" AndAlso d(ControlOnForm.Text) = 8 Then (only changed the 0 to

the 8 is for  End of Cycle Event  but now that I did that say I make the 5th combobox an end of cycle event i get an error on the sixth for "The given key was not present in the dictionary." The error is always on the combobox after the End of Cycle Event one.