Command handshake timeout

The
FactoryTalk® Batch
 Server uses a command handshake protocol to ensure that commands issued to phases are handled in a serial manner and are not lost or overwritten. The protocol has a configurable timeout period. When a command handshake timeout condition occurs, an error is generated in the phase object that represents the phase. The batch is then placed on HOLD, based upon the configured hold propagation settings. This allows the operator to disconnect the server from the affected phase should the timeout period expire. Without this feature, the server must be shut down and restarted if the phase stops responding.
When a command handshake timeout period occurs, the step representing the troubled phase in the
SFC
 display turns red and a failure is generated for the phase. The message PHASE NOT RESPONDING is shown on the status bar when the step is selected. It is also displayed in the
Phase List Display
 area of the
Phase Control
 window when the phase is selected.
A
System Message
 event type is logged into the electronic batch record. The description includes the fact that a time-out occurred and the type and ID of the command that timed out. In addition, the event is recorded in the
FactoryTalk Batch
 Server log file with a severity status of SEVERE and the description is the type and ID of the timed-out command.
If a communication error is detected while the command handshake is in process, the command handshake timer is stopped. The timer is reset and restarted if communication is successfully restored. If the command handshake completes after the timeout period, then the commands that are pending the handshake completion are processed. However, the error must be cleared before the batch can be restarted.
To restart a batch, you must issue the CLEAR_FAILURES command. If the command handshake completes successfully, the error is cleared and the batch can be restarted. Otherwise, the error is not cleared and the batch is not restarted. The operator should check the execution status of the process-connected device.
You can add a
FactoryTalk Batch
 Server extended property to configure the length of time, in seconds, that the
FactoryTalk Batch
 Server waits for a command handshake before issuing a timeout. If you do not configure this property, the timeout defaults to
60
. The valid range is 5 to 600.
To add a command handshake timeout property
  1. Open
    FactoryTalk® Administration Console
     and sign into the
    FactoryTalk
     Network Directory.
  2. In the
    FactoryTalk Administration Console
    Explorer
    , do one of the following:
    • For a new
      FactoryTalk Batch
       Server, right-click the application or the area name and select
      Add New Server
      FactoryTalk Batch Server
      .
    • For an existing
      FactoryTalk Batch
       Server, expand the application or the area name, right-click the server, and select
      Properties
      .
  3. In the
    FactoryTalk Batch
     Services Properties dialog, select the
    Advanced
     tab.
  4. In the
    Extended properties
     area, select
    Add
    .
  5. In the
    Add Extended Property
     dialog, enter a
    Name
     of
    CommandTimeOut
     and a
    Value
    , in seconds. If you do not enter a
    Value
    , the timeout defaults to
    60
    . The valid range is 5 to 600.
  6. Select
    OK
    .
  7. Select
    Apply
     to save the data in the
    Advanced
     tab.
  8. Because the
    CommandTimeOut
     value is read when the
    FactoryTalk Batch
     Server starts, if you change the value, you must stop and restart the server.
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