Test PSTN Connection

Associated with: Direct or Shared outstations that can fallback to PSTN

WARNING

UNEXPECTED BEHAVIOR OF APPLICATION

Use the Test PSTN Connection method with care. Always check an outstation’s current activity before deciding whether to use this action.

To check whether an outstation is currently processing a request, look at its entry in the Outstations List’s Current Request column. You can also check an outstation’s current activity via, for example, the Events List or the outstation’s Status display.

Failure to follow these instructions can result in death, serious injury, or equipment damage

The Test PSTN Connection method is available only on an outstation on which:

• PSTN fallback is supported and enabled (see Direct - PSTN Fallback)
• Your User Account is allocated the Diagnostic security permission.

With an outstation on which PSTN fallback is available, communications will automatically ‘fall back’ to using an available PSTN channel, should ClearSCADA detect that the direct communications has failed (see Direct - PSTN Fallback). Similarly, if an outstation is configured to Download Configuration via PSTN, communications will automatically switch to PSTN for the duration of a download (see Define an Outstation’s PSTN Properties).

To confirm that communication from ClearSCADA to the outstation using PSTN will succeed should it be needed, you can test the availability of the PSTN line using the Test PSTN Connection method. You can configure a Schedule Object to perform the test on a regular basis (for example,once a week) to verify the PSTN connection on a regular basis.

The Test PSTN Connection method does the following steps:

• Drops the current connection between ClearSCADA and the outstation.
• Dials the outstation using the configured PSTN settings. If the call fails (including any retries) then an alarm is raised to alert the user.
• Restores the normal connection between ClearSCADA and the outstation.