Skip to main content

Placeholders for Latch Data

You can temporarily store information that occurs during an alarm and retrieve it via latch variables. For example, when observing a motor speed, the temperature and the current are also recorded.

Latch variables are of the type scalar (8 bytes): STRING or WSTRING.

Tip

Hint: You can configure the alarm visualization in such as way that displayed alarms are filtered by the contents of the latch variables.

When a placeholder is inserted in the alarm message, the actual value is displayed at runtime instead of the placeholder. The following placeholders are supported.

Table 22. Placeholders in alarm messages

<DATE>

Date of change to the current alarm state

<TIME>

Time of the last status change

<PRIORITY>

Priority of the alarm (defined in the alarm class)

<TRIGGERVALUE>

Alarm triggering value

For the output, additional formatting information (as known from the C function printf) can be specified within angle brackets.

<ALARMID>

Alarm ID as displayed in the first column of the alarm table

<CLASS>

Name of the alarm class (defined in the alarm)

<ALLDEFAULT>

Full information about the alarm

<CURRENTVALUE>

Actual value of the latch variable

For the output, additional formatting information (as known from the C function printf) can be specified within angle brackets.

Example:

strAlarmmMessage : STRING := 'Der Wert beträgt <CURRENTVALUE %d>';

<LATCH1>

Data from the first latch variable at the time when the alarm was triggered

For the output, additional formatting information (as known from the C function printf) can be specified within angle brackets.

Tip

You can use more than two latch variables. To do this, insert additional columns from the context menu.

<LATCH2>

Data from the second latch variable at the time when the alarm was triggered

For the output, additional formatting information (as known from the C function printf) can be specified within angle brackets.

<LATCH<n>>

Data from an additionally inserted latch variable (via the context menu) at the time when the alarm was triggered

The index <n> in the variable name is automatically incremented.

For the output, additional formatting information (as known from the C function printf) can be specified within angle brackets.

<ALARM>

TRUE: Alarm state = Active

FALSE: Alarm state <> Active

<STATE>

Alarm state: <STATE>

  • The alarm is not active.

    Normal := 0

  • A state which indicates that the alarm condition is fulfilled but the alarm is not yet in the "Active" state.

    Pending := 1

  • The alarm is active.

    Active := 2

  • The alarm is no longer active, but needs to be confirmed.

    WaitingForConfirmation := 3

  • The alarm is active and has already been confirmed. The alarm still need to be become inactive.

    ActiveAcknowledged := 4

  • Alarm is inactive and need to be acknowledged.

    InactiveUnacknowledged := 5

For more information, see: Alarm Class



For more information, see: Using Latch Variables to Filter Alarm Events

: