Command handshake timeout

The

FactoryTalk Batch

Server uses a command handshake protocol ensuring 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, and the batch is 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 as well as 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.

In order 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.

The

Batchsvr.ini

file contains an item used to configure the length of time, in seconds, that the

FactoryTalk Batch

Server waits for a command handshake before issuing a timeout. If the item is not included in the

Batchsvr.ini

file, it defaults to

60

. The valid range is 5 to 600.

This value is read when the

FactoryTalk Batch

Server starts. If you change the value, stop and restart the server.