Profiles for WITS Database Points

You can configure WITS database points (except Binary points) to use limits that vary over time, instead of using fixed limits (example limits might be Low, Low Low, High, High High). To do this, you associate limits with a Time Profile. Time Profiles represent the different limits and times. For example, you could configure an analog point to use different limits on Saturday and Sunday to those it uses on Monday to Friday.

You can also configure WITS database points to be a specific value at a specific time. Once again, you do this by using a Time Profile.

Before you can do either of these things, you need to configure Time Profile items in ClearSCADA. For more information, see Configuring Time Profiles in the ClearSCADA Guide to Core Configuration.

To associate a WITS database point with one or more Time Profiles:

1. Log on to ViewX via a user account that has the Configure permission, and then display the Form for the point (see Display a Form in the ClearSCADA Guide to Core Configuration).
2. Select the <Point> tab.

3. In the Profiles section, there is one field for each limit. The number of Profiles fields varies depending on the type of point and the capabilities of your Field Device (see Display a WITS Device Profile). The fields are numbered to match the limits in the Alarm Limits section, so Profile 1 matches Alarm Limit 1, Profile 2 matches Alarm Limit 2 and so on. Use the browse button for each field to locate and select the Time Profile that you want to associate with the limit.

   NOTE: For each limit, you can use a fixed limit or a Time Profile, but not both. For example, if you configure a profile for a limit, you cannot also specify a fixed limit (the field is grayed out).

4. If you want, you can use a Time Profile to set the point to a specific value at a specific time. Use the Control field to specify the Time Profile you want to use.

   Use the Interpolation Time field if you want to set the point to intermediate interpolated values between adjacent vectors in the Time Profile. Enter how frequently, in minutes, you want the Field Device to calculate an interpolated value (for example, every 30 minutes). Enter 0 if you want the Field Device to step between the set values in the Time Profile (that is, no interpolation). The device profile defines what interpolation times the Field Device supports (see Display a WITS Device Profile). Enter an interpolation time that is a whole fraction of a day (there are 1440 minutes in a day).

   NOTE: There is no Interpolation Time field for Binary Point profiles.

   Example:

   In the Control Time Profile: At 16:00 the point is set to a value of 50. At 18:00 the point is set to a value of 90.

   In the Interpolation Time field, you enter 30 minutes.

   In this situation, the Field Device will set the point to a value of 50 at 16:00. It will then set intermediate interpolated values of 60 at 16:30, 70 at 17:00 and 80 at 17:30. The Field Device will then set the point's value to 90 at 18:00.

   If you enter 0 in the Interpolation Time field, the Field Device will set the point to a value of 50 at 16:00, and the point will remain set at 50 until 18:00, when the Field Device will set the value to 90. The Field Device has 'stepped' between the values at 16:00 and 18:00, with no intermediate interpolated values.

5. Save the configuration.

6. When you have completed the point configuration, you will need to download it to the Field Device by using the Outstation item's Download Configuration (WITS Outstation) action.

   If your Field Device does not support download configuration, you will need to make the same changes to the Field Device's configuration locally.

When you have associated a Time Profile with a limit, you can view the effect of the Time Profile by displaying the current Trend for the point (right-click on the point and select Display Current Trend). By default, the Time Profile limit is shown on the Trend along with the alarm limits.