#### Working with Alarms and Control Limits

When you right-click inside the List View, you can use the Alarms or Control Limits shortcut menu items.

Menu Item | Description
Alarms | Acknowledge to Current - This menu item acknowledges the selected variables displayed in the alarm colors. Acknowledging out of control or out of tolerance variables has the following effects:

- The date and time of the acknowledgment is recorded.

- The cause is recorded.

- The color status of the variable changes to GOOD. (This taken from legacy Dp documentation. Currently not available in Dp+ 2011. Maybe in a future version?)

- The software recalculates control limits using data from the recorded date/time forward; all previous data is disregarded. (This taken from legacy Dp documentation. Currently not available in Dp+ 2011. Maybe in a future version?)

Set Acknowledge Date - This displays the Acknowledge dialog box.

Acknowledge dialog box

- Last DateTime - Uses the date and time used on your last Acknowledged item. If this is your first Acknowledged item, it uses the current date and time.

- Current DateTime - The date and time for the Acknowledged item is set to your current system time.

- Other DateTime - The drop down provides you with tools to define your own date and time for the Acknowledged item.

- Select cause - This lets you choose the cause to be displayed for the Acknowledged item. Causes can be defined by a user with administrator privileges using the Data Editor tab in Datapage+. Causes can be defined by a user with administrator privileges using the Data Editor tab.

Unacknowledge - This menu item returns out of tolerance or out of control variables to unacknowledged status. The system will calculate control limits for unacknowledged variables using all available data.

View Acknowledged Date - This menu item displays a small message box with the date and time that the selected item was Acknowledged:

Control Limits | The Control Limits menu tab can calculate and freeze control limits at their current values for any selected variable(s). When new data is brought into the database, control limits for these variables will not be affected. You can unfreeze the limits later, if you wish.

Control limits detect signals in the process data, indicating unpredictable or out of control processes.

Set Out of Tolerance/Control - This lets you manually calculate control limit parameters. This option displays the Select Transactions dialog box:

Select Transactions dialog box

Manual Selected - This option will use any transactions you selected manually from the transaction list before accessing this dialog box.

Auto select - This option will use a query you select from the drop-down list.

One month - This check box option lets you select an entire month of transactions. Simply define any day of the month you want and all transactions for that month will be used.

When you click OK, the control limits are automatically calculated in the background.

Usually, when you apply part data to one of the tabs in the main view, the control limits are calculated automatically. This option is useful if you plan on exporting part data to an Excel file without ever applying data to a tab.

See also:

- The Set Control limits menu item contained under the Options toolbar icon of the Data Editor tab.

- Control Limits

Freeze Control Limits - This freezes control limits at their current level for the selected variables, so that the limits will not be recalculated when new data is added to the database.

Unfreeze - This allows the software to recalculate control limits for the selected variables each time new data is added to the database.

View Frozen Control Limits - This displays the frozen control limits for the selected variable.

Note: Use the Calculations dialog box (Tools | Calculations) to view or change the methods used to calculate control limits.