Probe operation

Once connected to the device, the probe can perform various functions.

When connected to the device, the probe can perform the following functions:

  • Get historical data
  • Request heartbeats
  • Listen for unsolicited alarms
  • Interrupt the unsolicited alarm state
  • Send a disconnection warning

The probe operates in the following states, as described below, to perform it's functions:

  • Connection state
  • Login state
  • First Heartbeat state
  • Resynchronization Initialization state
  • Resynchronization Processing state
  • Unsolicited state
  • Periodic Resynchronization Initialization state

Connection state

The ConnectionTimeout property specifies the length of time allowed for the probe to make the connection.

If the probe connects successfully within the time specified by the ConnectionTimeout property, the connection is confirmed and the probe proceeds to the Login state.

Login state

The probe sends a CONNECT-REQUEST command (or primitive) to the interface. This command includes an authentication key. You must specify the authentication key using the AKey property.

If the probe receives no response from the interface within the length of time specified by the LoginTimeout property, it attempts to reconnect and log in again. If the probe receives a CONNECT-REJECT response, the connection has been rejected by the interface and the probe exits. If the probe receives a CONNECT-CONFIRM response, the connection has been confirmed and the probe proceeds to the First Heartbeat state.

First heartbeat state

The probe sends a HEARTBEAT-REQUEST command to the interface to ensure that the connection is active.

If the probe receives no response from the interface within the length of time specified by the HeartbeatTimeout property, or if the response is not the expected heartbeat response, the probe reconnects and logs in again. If the probe receives a HEARTBEAT-CONFIRM response from the interface, the heartbeat has been confirmed and the probe proceeds to the Resynchronization Initialization state.

You can instruct the probe to skip the First Heartbeat state by setting the HeartbeatInterval property to 0.

Resynchronization initialization state

The probe requests the list of active alarms that exist in the element manager.

Resynchronization processing state

The probe receives all outstanding active alarms from the element manager. At the end of the data stream, the probe receives a DATA-END-NOTIFICATION response. The probe then proceeds to the Unsolicited state.

The SynchronisationTimeout property specifies the length of time that the probe waits to receive notification at the end of a resynchronization.

Unsolicited state

The probe receives all unsolicited alarms as they are generated by the element manager.

While in this state, the probe sends periodic heartbeats to the interface when the device becomes idle. To specify the length of time of the heartbeat interval, use the HeartbeatInterval property.

Note: If the HeartbeatInterval property is set to send heartbeats without any idle period and the RestartOnIdleTimeout property also allows the sending of heartbeats to the device, the resulting frequency of heartbeat requests may affect the performance of the probe.

You can limit the number of heartbeats that the probe sends to the device using the RestartOnIdleTimeout property. If this property is set to 0, the probe sends unlimited heartbeat requests to the device.

If the ResynchInterval property is set to a value greater than 0, the probe proceeds to the Periodic Resynchronization Initialization state once the specified length of time has elapsed. A value less than 0 adversely affects the performance of the probe.

Periodic resynchronization initialization state

The probe requests the list of active alarms that exist in the element manager using the LIST-CURRENT-ALARMS-REQUEST command.

If the probe receives no response from the device within the length of time specified by the RequestTimeout property, or if the response is not the expected list of current alarms, then the probe waits for the length of time specified by the ResynchInterval property before trying to reconnect.

If the probe receives a LIST-CURRENT-ALARMS-CONFIRM response, the confirmation has been received and the probe returns to the Resynchronization Processing state.