# Learning Lab - Operational Start Up Part 1

Discussion created by Pablo Benvenuto on Sep 12, 2012
I have an interesting Lab for you today that will help you learn how to retrieve process data using the Compressed Data function.

Consider the following scenario, someone at the plant was recently fired because they have not been watching energy usage on startup of a key piece of equipment and operating costs are up 1200 %. This piece of equipment is now yours. You want to determine if there is any deviation between startup operations by examining today and comparing it to the same time period from the day before. The tag you want to use as a metric is CDT158. Your shift begins at 6:30 am in the morning and you want to gather the first 30 values beginning at that time for today and yesterday, and do some quick math to determine the deviation. A ten percent deviation in a positive or negative direction will be considered over / under range. All other outcomes will be considered nominal.

General approach

No worries.  I will use a template that you can download here, or you can use the OSIsoft Virtual Learning Environment and open the template located in C:\Labs\Visuals\Operational Start Up\Workspace.

This task is very straight forward and you may want to give it a shot without reading step by step instructions since you already have the template.  You can open the template and retrieve the first 30 values today using the tag CDT158. We want to compare these values to the previous day’s starting 30 values. Fill in data into all of the fields in the template.  Both queries are using the Compressed Data (Number of values) query. Use cell references for all of the dialog box fields. The formulas used to compare the two queries are found in the upper right portion of the spreadsheet. They both have a single quote inserted before the equal sign so Excel will treat them as strings and not formulas. You can copy and paste the contents and then remove the leading single quote.

Go ahead, give it a try, the results should look like the picture below:

If you are ready to try the step by step solution, go to Part 2.