Heartbeat

Init Heartbeat

The "Init Heartbeat" block creates a Heartbeat instance. Based on the client handle (see Init), a scan is performed for each registered target to determine whether an instance of FB_Heartbeat exists. If this is the case, connection monitoring is prepared for each heartbeat found. If no instance of FB_Heartbeat is found at any target, the VI returns the error -8114.

FB_Heartbeat The FB_Heartbeat function block can be found in the Tc3_HeartbeatConnectionMonitoring library and must be created and called in the project for which connection monitoring is being set up.

The block also creates a Heartbeat event. This can then be used to query the status of the connection. As soon as the status of the connection changes, a Heartbeat event is generated. The Heartbeat event has the following event dates:

• HeartbeatHandle: Handle to the Heartbeat instance from which the event was generated.
• TargetAddr: String containing the AMS address (NetId:Port) of the target from which the Heartbeat event was triggered.
• Connection State: Enum that specifies the reason for triggering the Heartbeat event.
• Waiting: Heartbeat initialized, connection monitoring not (yet) started.
• Connected: Connection monitoring started.
• Timeout detected: Connection monitoring has detected an interruption.
• Stopped: Connection monitoring has been stopped.
• Error: An error has occurred during connection monitoring (error code is provided at the Heartbeat output. If more than one target is monitored, only the connection monitoring for the corresponding target is stopped; the others continue to run).
• Reserved: reserved (ignore)

Run Heartbeat

The Run Heartbeat block is used to start and continuously execute connection monitoring. This block is executed until the connection monitoring is stopped with the Stop Heartbeat.

Stop Heartbeat

The Stop Heartbeat block is used to stop connection monitoring.

Release Heartbeat

The Release Heartbeat block releases the handle to the Heartbeat connection monitoring from the memory.

Get RTD Estimate

The Get RTD Estimate block returns the current (maximum) roundtrip delay (RTD) estimate for the selected target. The target can be selected via the "TargetAddr" string. If the string is empty, the target found first is automatically selected. To use this block, it is necessary to execute the Heartbeat connection monitoring (see VIs described above).

Heartbeat

The Heartbeat block uses the Init Heartbeat, Run Heartbeat, Stop Heartbeat and Release Heartbeat blocks internally to enable the use of Heartbeat connection monitoring with just one block. The Heartbeat block also serves as an illustration of how Heartbeat connection monitoring can be used and edited.

Heartbeat connection monitoring is carried out continuously until it is stopped via a control. If the connection monitoring detects an interruption (timeout), an attempt is made to call up a VI (vi path timeout detected). If it is not possible to call the VI, the block and Heartbeat connection monitoring are stopped. At the output of the VI, the target for which an interruption was detected is then displayed via Timeout detected and the TargetAddr. If there are several interruptions, only the first interruption is displayed.