Hi,

I'm trying to read values every second from an RTD server to an Excel
spreadsheet using a macro. Problem is when I run the macro, values from
the RTD server is not updated. I've tried to set the calculation mode to
manual, and then force a calculation everytime I want to read data, but
it doesn't work. It gives me the same value all the time. Here's the
code I'm using:

Public Sub Start_Logging()

Dim x As Integer

Dim intNewHour As Integer
Dim intNewMinute As Integer
Dim intNewsecond As Integer
Dim varWaitTime As Variant

blnLogg = True
x = 1

Application.Calculation = xlCalculationManual

Worksheets("Sheet1").Activate
ActiveSheet.Cells(1, 1).Select

Do
'Set logging to every second
intNewHour = Hour(Now())
intNewMinute = Minute(Now())
intNewsecond = Second(Now()) + 1
varWaitTime = TimeSerial(intNewHour, intNewMinute, intNewsecond)
Application.Wait varWaitTime

'Do full calculation
Application.CalculateFull

'Write new value to cells
ActiveSheet.Cells(x, 1).Value = TIME
ActiveSheet.Cells(x, 2).Value = ActiveSheet.Range("e2").Value

x = x + 1

DoEvents

Loop Until blnLogg = False

Application.Calculation = xlCalculationAutomatic

End Sub

If I place a comment mark in front of the "do" and "do until..." and
"application.calculation....", so I have to run the macro everytime to
read/write values, it's working. So the problem has something to do with
the Do...Loop.

The blnLogg is a flag I use, so I can stop updating pressing another
button, setting the flag to false.

Running Windows XP SP2, Excel 2003.

Regards,

Anders Frafjord