38
Collecting Data:
The RS-232 / RS-485 output updates to the screen many times per second. Very
short-term events can be captured simply by disconnecting (there are two telephone
symbol icons at the top of the HyperTerminal® screen for disconnecting and
connecting) immediately after the event in question. The scroll bar can be driven up
to the event and all of the data associated with the event can be selected, copied,
and pasted into Microsoft® Excel® or other spreadsheet program as described below.
For longer term data, it is useful to capture the data in a text file. With the desired
data streaming to the screen, select “Capture Text” from the Transfer Menu. Type
in the path and file name you wish to use. Push the start button. When the data
collection period is complete, simply select “Capture Text” from the Transfer Menu
and select “Stop” from the sub-menu that appears.
Data that is selected and copied, either directly from HyperTerminal® or from a text
file can be pasted directly into Excel®. When the data is pasted it will all be in the
selected column. Select “Text to Columns...” under the Data menu in Excel® and a
Text to Columns Wizard (dialog box) will appear.
Make sure that “Fixed Width” is selected under Original Data Type in the first dialog
box and click “Next”. In the second dialog box, set the column widths as desired,
but the default is usually acceptable. Click on “Next” again. In the third dialog
box, make sure the column data format is set to “General”, and click “Finish”. This
separates the data into columns for manipulation and removes symbols such as
the plus signs from the numbers. Once the data is in this format, it can be graphed
or manipulated as desired.
For extended term data capture see page 39.
Data Format:
The data stream on the screen represents the flow parameters of the main mode
in the units shown on the display.
For mass flow controllers, there are six columns of data representing pressure,
temperature, volumetric flow, mass flow, set-point, and the selected gas
The first column is absolute pressure (normally in psia), the second column is
temperature (normally in °C), the third column is volumetric flow rate (in the
units specified at time of order and shown on the display), the fourth column is
mass flow (also in the units specified at time of order and shown on the display),
the fifth column is the currently selected set-point value, the sixth column
designates the currently selected gas. For instance, if the controller was ordered
in units of scfm, the display on the controller would read 2.004 scfm and the last
two columns of the output below would represent volumetric flow and mass
flow in cfm and scfm respectively.
+014.70
+025.00
+02.004
+02.004
2.004
Air
+014.70
+025.00
+02.004
+02.004
2.004
Air
+014.70
+025.00
+02.004
+02.004
2.004
Air
+014.70
+025.00
+02.004
+02.004
2.004
Air
Pressure
Temp
Vol. Flow
Mass Flow
Set Point
Gas
MC-Series Mass Flow Controller Data Format
Note:
On units with the totalizer function, the sixth column will be the totalizer
value, with gas select moving to a seventh column.
