Data Logger Setup

Data Logger Setup
Setup:

There are two methods of setting up the HP 34970A Data Acquisition unit for testing the DEIMOS Dewar temperature gradients.

From the front panel: Start at channel 101 and with the "measure" button, select OHMS, 1K RANGE & 5 ½ DIGITS.

Set the screen to OHMS again with the "measure" button, and rotate the knob counter-clockwise to "COPY CONFIG". Press the "measure button to get "PASTE TO", and select the next channel. (Channel 102 will be selected automatically.) Continue this process until all the channels are configured.

Bring up dlogger.exe on your PC. If you have not already done so, establish communications between the Data Logger and The PC.

Connect an RS-232 cable between port 2 on your PC and the RS-232 port on the back of the Data Logger. You will probably need a null modem cable for this connection.

From the Data Logger window, select "Instrument/Communications Setup/Change Settings".

Select: COM 2, 19200 baud, None, 8 bits and XON/XOFF. (Check that these are the same settings setup on the Data Logger.)

Select "Create a new setup" Fill in the lines in the Excel-looking chart. (An easy to do this is to set up the first line, and then cut-and-paste the rest as a group.) Select: Scans = 1 through 15, Function = 2w ohms, Range = 1K, Resolution = 5.5 digits and the rest are default settings.

Now click on the "Download icon". It looks like a page of graph paper with a blue down-pointing arrow to the right. Then accept " Continue with the Download operation".

Scanning:

Once you are set up, you need to select the type of scan you are going to perform. On the Data Logger push the "Interval" button. (Note: if there is no response from the buttons, see if you are still in "RMT" mode. If you are, push the "Shift" button once.) Select "INTERVAL SCAN", push the button again and with the knob and "left" button above, select 5-minute intervals. With the button and knob again, select "CONTINUOUS".

Start the scan by pushing the "Scan" button. This will erase all the old data and begin a continuous set of 5- minute scans. At the end of each five-minute interval the data from the diodes will be recorded.

When you are finished scanning, push and hold the "Scan" button until it responds with "SCAN STOPPED". The Data Logger can now be turned off because the data is stored in non-volatile memory. It will only be lost if you reset or start another scan.

Transferring Data from Data Logger to PC:

Be sure you have established communications between the data logger and your PC.

Run Dlogger.exe (Click on the Data Logger icon if you have set up a shortcut.).

"Cancel" the welcome window

Click on Instrument / Communications Setup / RS-232 / HP34970A / COM2 / OK
Click on Instrument / Upload Setup

CAUTION: Under some circumstances, if you upload the setup without the data, the data will be lost. Be sure that the "Upload Options / Include data in upload" box in the lower left of menu is checked.
The data is uploaded, and the setup is displayed on a new screen.
Click on "File" and select "Export Data", "Save" data to disk and note the file name. (Check that it is not a file that already exists.) Click "OK"

Data Reduction:

Once you have uploaded the data, locate ".csv" file that is readable by Excel.

Open Excel and import the new file. Answer the formatting questions and graph the file using the Graph Wizard.