This is a short Learning Lab to help you become acquainted with the differences and similarities between PI and Excel time notations.

You can follow this lab by using your production environment or you can obtain a subscription to the OSIsoft Virtual Learning Environment, which allows you to work hands on in any of the Learning Labs published in this community.

We will start with a template in Excel that will allow you to compare PI and Excel times side by side. The template can be downloaded from here and it looks like this:

The spreadsheet contains a number of ranges and points in time listed in column A, and we are going to represent them with PI and Excel notation. First, we will retrieve a PI Tag value using the Archive Value function using the PI time on one column and using the Excel time on a different column. We will then compare the two notations by comparing the time stamps associated with the two values retrieved.

We will start with the simplest of PI Times, which is now and represented by *

Now we can repeat the same process to retrieve the same value with Excel time. The corresponding function in Excel is

Because now is a relative time, the two timestamps in cells C6 and F6 may not exactly match right now, because they were retrieved at different times. What we need to do now is update or recalculate the spreadsheet so that the value is retrieved at the same time. Interestingly and as a side note, F9 will only recalculate volatile functions in Excel, such as NOW(), but not Archive Value which is not a volatile function. In order to recalculate all functions on the spreadsheet at the same time we can press

The next time in the list is 8 hours ago, which can be represented as *

Now select cell

For the last example of a relavtive time we have 2 days ago. We can simply represent this as

Good job making it this far, you are in a roll. So don't waste any time and go to Part 2 of this Learning Lab.

You can follow this lab by using your production environment or you can obtain a subscription to the OSIsoft Virtual Learning Environment, which allows you to work hands on in any of the Learning Labs published in this community.

We will start with a template in Excel that will allow you to compare PI and Excel times side by side. The template can be downloaded from here and it looks like this:

The spreadsheet contains a number of ranges and points in time listed in column A, and we are going to represent them with PI and Excel notation. First, we will retrieve a PI Tag value using the Archive Value function using the PI time on one column and using the Excel time on a different column. We will then compare the two notations by comparing the time stamps associated with the two values retrieved.

**Relative times**We will start with the simplest of PI Times, which is now and represented by *

**.**If you are using the excel template, simply type*****right next to "Now (current time)" and under the "PI Times Abbreviation" column in cell B6. We will now place the PI Tag value and its timestamp right next to it. Select cell**C6**and click on**PI > Archive Value**. in the function dialog window, select the**Tagname**field and click on cell**B1**, where the name of the tag CDT158 is contained. Select the**Timestamp**field and click on cell**B6**where * is. At last select the**time at left**option from the dialog window and click on**OK**. A timestamp will be displayed on cell C6 and its corresponding value on cell D6.Now we can repeat the same process to retrieve the same value with Excel time. The corresponding function in Excel is

**NOW()**. So we can type**=NOW()**in cell**, and we can see that Excel immediately displays the current time. We can select cell****E6****F6**, click on the**Archive Value**function and select cell**B2**for the**Tagname**and cell**F6**for the**Timestamp**. We select the**time at left**option and click on**OK**. The timestamp and value retrieved will be displayed on cell F6 and G6 respectively.Because now is a relative time, the two timestamps in cells C6 and F6 may not exactly match right now, because they were retrieved at different times. What we need to do now is update or recalculate the spreadsheet so that the value is retrieved at the same time. Interestingly and as a side note, F9 will only recalculate volatile functions in Excel, such as NOW(), but not Archive Value which is not a volatile function. In order to recalculate all functions on the spreadsheet at the same time we can press

**CTRL + ALT + F9**. This combination will recalculate all functions, retrieving both values at the same time. Comparing the timestamps we can see that * and NOW() produce the same result with the same timestamp.The next time in the list is 8 hours ago, which can be represented as *

**-8h**in PI. Since Excel stores dates as whole number of days starting at 1900, dates and times are values and therefore can be added, subtracted, and included in other calculations. We can write**=NOW()-(8/24)**. We can now follow the same process as before to retrieve the PI Tag value. Select cell**C7**and click on**Archive Value**. When the dialog window opens, select**B2**as the**Tagname**and**B7**as the**Timestamp**. Select the**time at left**option and click**OK**.Now select cell

**F7**, click**Archive Value**and make the same selections as before in the dialog window, using the Excel time as Timestamp. Once again we will have to recalculate the spreadsheet to compare these relative times. Pressing**CTRL + ALT + F9**will show that these expressions are equivalent because the timestamps and the values retrieved are the same.For the last example of a relavtive time we have 2 days ago. We can simply represent this as

***-2d**in PI notation and as**=NOW()-2**in Excel notation. Every unit in Excel represents a day. We can now retrive the corresponding Archive Value and place the timestamps in cells C8 and F8. Recalculating we see that the times match and the spreadsheet now looks like the picture below.Good job making it this far, you are in a roll. So don't waste any time and go to Part 2 of this Learning Lab.

I'm stuck. I am remoted into the Virtual Learning Lab's Excel.

The instructions say " Select cell

C6and click onPI > Archive Value."Where is this

PIbutton??I can click on

PI Datalink > Archive Value, BUT this doesn't bring up the same menu as the ones shown in the screen shots.What am I missing??

Thank you!