MODBUS communication status

[ansab.tp]

Hi,

I want to access the invalid bit of a variable so that i can assign a particular value to an internal variable based on whether the variable status is valid or not. the VB script i am using is written below: (here DI and Test are analog modbus driver variables and VBA is an internal variable of type UINT)

Public Sub test()

Dim i, j, k As Variable
Dim l As Long

Set i = thisProject.Variables.Item("DI")
Set j = thisProject.Variables.Item("Test")
Set k = thisProject.Variables.Item("VBA")
l = thisProject.Variables.Item("DI").StatusValue
'DI1=open and DI2=close
If (l = H0x00040000) Then
k.Value = 5
ElseIf (i.Value = 0 And j.Value = 0) Then
k.Value = 0
ElseIf (i.Value = 0 And j.Value = 1) Then
k.Value = 1
ElseIf (i.Value = 1 And j.Value = 0) Then 'Set thisProject.Variables.Item("VBA").Value= k.Value

End If
End Sub

But this is not working when the variable is invalid. How can i access the invalid bit of the variable?

[herberto]

Why do you want to do this via VBA?

Simply use a Reactionmatrix, watch the Invalid-Bit and link the function "Send value to hardware" to write the desired value to the other variable.

Regards,
Herbert

[ansab.tp]

I can use the reaction matrix in case of different values for one driver variable.Here am using different driver variable for different status of one object. ( eg:- CB open is in one variable, close in another variable) so i need to access it through VBA because the combined element in the Screen changes according to the value of that internal variable. so the red box in the corner which appears when there is a communication error will not appear for the internal variable.

So i need to pass the invalid bit status of the driver variable to one internal variable.

[johannes.foidl]

hi

If you want to pass something from one variable to another you may use the allocations. Use your driver variable as "source variable" and the intern variable as "target variable", this way also the state of the variable is passed on. Check out the zenon help for detailed information on how to create such an allocation.

[ansab.tp]

In our project we have some five thousand odd objects. Since i am already writing a VB script for assigning the conditions like breaker open, close, intermediate etc it would save a lot of development work for me if i can access the invalid bit through VB.

[herberto]

use .StatusString() and check for the "Invalid" Status
-> since a variable can have several variable status you have to search within the status string with VBA function instr()

Also note, if you want to monitor all those variables (reading the variable status) you have to take care that those variables are advised on the driver (you can check this with the medthod .IsOnline)

For the Reactionmatrix
-> you only have to define 1 Rema and you can link this to all the variables you want to monitor...

Regards,
Herbert

[ansab.tp]

thank you....

It is working now....