More than likely, when you create your graph, the scaling will not be correct for the expression you entered. Fortunately, DAQFactory provides quite a few ways of setting the scaling of your graph.
Scaling Properties:
The scaling of an axis is initially determined by the settings in the properties box. If you open the properties box for the graph and select the Axes sheet, you will see a list of the thirteen possible axes along the left side. You can select any of the axes and the scaling parameters for that axis, along with the rest of the parameters for that axis, will be displayed in the rest of the box. Although all the axes parameters are available, only the axes that have traces assigned to them are displayed. Multiple axes are explained a little later.
For all but the bottom axis, there are two scaling parameters, Scale From and Scale To. These determine the minimum and maximum values for the axis. You may notice that these parameters are actually expressions, so you can enter in fixed values if you would like, or you can enter in a more complex expression such as Max(channel). If the bottom axis is displaying time, you can also have DAQFactory automatically set your scaling parameters so that the most recent data point is always displayed, and the traces scroll across the graph. Instead of using the Scale From and To parameters, you will use the Time Width parameter. Check the box to the left of Time Width then enter the width of the bottom axis in seconds in the field to the right. This field, like the Scale From and To, is an expression, so you can use a fixed value or a complex expression.
Even though you can quickly access the scaling parameters by double clicking on the desired axis, changing the scaling by always going to the properties box can be somewhat cumbersome. Because of this, DAQFactory provides several features for zooming and autoscaling.
Autoscaling:
To autoscale a graph, simply right click on the graph, select Autoscale from the popup, then choose the desired axis to autoscale from the submenu. This will scale the axis to completely display the traces on the axis. With stacked axes, which axes get autoscaled depends on where you right click. You can also use Autoscale From which does the same thing as autoscale, except that it replaces the minimum axis scaling with the value from the Autoscale From property for the axis, available on the Axes sheet of graph property page. If the maximum axis scaling value is less than this value, then it is replaced instead.
Zooming:
DAQFactory provides several zooming options. To zoom in a graph, click and drag a box around the area you would like to zoom in to in your graph. Right click inside the zoom rectangle and select the desired zoom axes. You can also zoom out, which adjusts the desired axes proportional to the zoom rectangle size. Once you are zoomed in, you can restore the previous zoom by selecting Zoom Previous from the regular graph popup which appears when you right click on your graph anywhere but inside the zoom rectangle. You can also pan the graph by holding down the Shift key and click and dragging inside the graph.
Freeze / Thaw:
The autoscaling, zooming, and panning options discussed so far will freeze the scaling of the graph on the axes in which they apply. In this case when we are referring to an axis we are referring to all the Y axes, or the X axis, not just a single Y axis. A frozen axis does not use the Scale From, Scale To, or Time Width parameters from the graph parameters box. Therefore changing these parameters will not have any affect on the graph scaling if the axis is frozen. Likewise, a frozen X axis will not automatically scroll. The easy way to tell if an axis is frozen is to look at the focal rectangle around the graph. A non-frozen, or thawed graph will display the rectangle in green. If the X axis is frozen, then the left and right sides of the rectangle will be drawn in purple. If the Y axes are frozen, then the top and bottom sides of the rectangle are drawn in purple. You can freeze an axis manually, or restore / thaw an axis by right clicking on the graph and selecting Freeze / Thaw then selecting the desired axes. Thawing a particular axis will cause the scaling to revert back to the settings in the properties box. Freezing the X axis on a time graph manually can often be handy when you want to stop the constant march of your data across the graph, and is especially useful in this situation when using markers. If you like your new scaling and would like to set the scaling properties of an axis to what is displayed, you can open the axis sheet and press the Copy from Zoom button. This will make the scaling match the current max and min values of the axis. Note that this will overwrite any complex expressions you may have entered for these parameters.
Zoom In/Out Time:
DAQFactory provides one other zooming feature that does not affect the freeze / thaw status of the graph. This is Zoom In Time and Zoom Out Time. You can access these options from the same menu as the other zooming functions. These work just like Zoom In / Out Horiz, except that on a time graph, these functions do not freeze the graph, but instead change the Time Width parameter directly.
