Skip to Content
avatar image
Former Member

Generate Trend for Dynamically passed Tag Name

Hi All,

Request to provide solution for the below mentioned query

<b>Basis:</b> Availability of tag values fetched from RS SQL DB (app. 40 different equipment tags, updated in RS SQL DB at different intervals by PLC)

<b>Assumption:</b> 4 concurrent users logged in to xMII

<b>Objective:</b>

a. To add tag name dynamically (from a drop down menu) into a trend and display a line chart for the tags selected (Functionality similar to a trend created in PLC SCADA HMI)

b. On return to trend page (in xMII), should display the chart for the tag names added previously.

<b>Procedure followed</b>

a. Select a Start and End Date for the line chart to be displayed

b. Select a tag name from the drop down menu

c. On click of Add button, trend for the selected tag should be displayed on line chart

d. Repeat steps b & c for selection of desired tag names (maximum upto 10 tags) and display trend

e. We are looking at the facility to remove the selected tag from the trend as well

<b>Query:</b>

a. We have 4 different users performing the same activity, for the procedure (steps) mentioned above (for trend display), how to avoid the clash of addition / deletion of the tag names on Line chart performed by these users.

Solution or hints at the earliest is highly appreciated.

Thanks and regards,

Deepak

Add comment
10|10000 characters needed characters exceeded

  • Get RSS Feed

1 Answer

  • avatar image
    Former Member
    Mar 07, 2007 at 04:38 PM

    This is very possible to do and in fact, very common.

    Since your 4 users will be using their own clients and browsers, there is no concern of a clash. Each user will have their own instance of the chart in their own browser.

    Add comment
    10|10000 characters needed characters exceeded

    • Former Member

      Ryan:

      The challenge is that RS/SQL is not, by default, a "Tag" connector. If the underlying query is a SQL query, I recommend dynamically manipulating the "where" clause with the list of selected tags. I would use the [SD] and [ED] tokens and the built-in date selection engine.

      Alternatively, a very cool but little known feature of xMII is called the "Open Connector" - it allows you to model a Tag-based connector by providing SQL queries for listing groups, tags, reading values, etc...with this approach, the user can even right click on the chart and browse/select tags with no coding!

      That's probably the technique I would recommend.

      - Rick