Hope to stock data at every single update&all the sheets stocking synchronized
 

I have the following coding:

Sub Update()
Dim myCell As Range
NextTime = Time + TimeValue("00:00:01")
Range("B5:G7").Copy
Set myCell = Cells(Rows.Count, 2).End(xlUp)(2)
myCell.PasteSpecial _
Paste:=xlPasteValues
With myCell.Offset(0, -1).Resize(3)
.Value = Now
.NumberFormat = "mm/dd/yy hh:mm:ss"
End With
Application.OnTime NextTime, "Update"
End Sub

Thanks a lot Bernie Deitrick last time for helping with this.

Now I hope to improve for 2 points:

1, Instead of every 1 second to stock the undated data, I hope to
stock whenever there is a update in the Range.

2, I hope to synchronize several sheets(say sheet 1, 2 , 3) of this
realisation.

Thanks in advance for all the possible help