Excel: Not unable to update automatically after trigger - excel

Question

I have a cell A1 which extracts values from a server every n seconds, however using the macro below (which is currently used) is not suitable:
Dim preVal As String
Dim count As Integer
'Intention is if cell A1 changes, record changes to Column C and Column D
Private Sub Worksheet_Change(ByVal Target As Range)
If Target = Range("A1") Then
Call cellchange(Range("A1"))
End If
End Sub
Private Sub cellchange(ByVal a As Range)
'If row is empty, filled into that row, if not skip to next one
If a.Value <> preVal Then
count = count + 1
'copy the value of A1 from sheet 1
preVal = Sheets("Sheet1").Range("A1").Value
Cells(count, 4).Value = a.Value
'copy the values of time of which data change detected
Cells(count, 3) = Now()
End If
End Sub
In a simplest way, the cell A1 will be updated every few seconds from a server, so I need the macro to be updated/trigger when it detects changes in cell A1 that are not from human input.

Answer 1

You need to use something that really checks if your target cells is updated. usually application.intersect are used. Here I am using address property.
Dim preVal As String
Dim count As Integer
'Intention is if cell A1 changes, record changes to Column C and Column D
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.address = Range("A1").address Then
cellchange target
End If
End Sub
Private Sub cellchange(ByVal a As Range)
'If row is empty, filled into that row, if not skip to next one
If a.Value <> preVal Then
count = count + 1
'copy the value of A1 from sheet 1
preVal = Sheets("Sheet1").Range("A1").Value
Cells(count, 4).Value = a.Value
'copy the values of time of which data change detected
Cells(count, 3) = Now
End If
End Sub
Hope it helps.
Regards,
M