Technical information

Controller States and Behaviors
56
EIO0000000638 04/2012
Controller States and Output Behavior
Introduction
The XBT GT/GK HMI Controller defines output behavior in response to commands
and system events in a way that allows for greater flexibility. An understanding of
this behavior is necessary before discussing the commands and events that affect
controller states. For example, typical controllers define only two options for output
behavior in stop: fallback to default value or keep current value.
The possible output behaviors and the controller states to which they apply are:
z ControllerLockout Feature
z Managed by Application Program
z Keep Current Values
z Set All Outputs to Default
z Output Forcing
ControllerLockout Feature
The ControllerLockout feature locks or unlocks the controller stop mode. A locked
controller cannot be restarted until the controller is unlocked.
Attempts to restart a locked controller are ignored and a message appears.You can
only initiate lockout once the controller is in STOPPED state. If the controller is in
RUNNING state and you attempt to lockout, the attempt is ignored and a message
appears.
The ControllerLockout is not managed through SoMachine, it is an internal
boolean variable (_ControllerLockout) of the HMI in Vijeo Designer.
For more information on managing this variable, refer to the Vijeo Designer Online
Help.
Managed by Application Program
Your application program manages outputs normally. This applies in the RUNNING
and RUNNING with External Error states.
Keep Current Values
You can select this option by choosing Keep current values in the Behaviour for
outputs in Stop dropdown menu of the PLC Settings sub-tab of the Controller
Editor. To access the Controller Editor, right-click on the controller in the device tree
and select Edit Object.
This output behavior applies in the STOPPED and HALT controller states. Outputs
are set to and maintained in their current state, although the details of the output
behavior varies greatly depending on the setting of the Update IO while in stop
option and the actions commanded via configured fieldbuses. Refer to Controller
States Description (see page 52) for more details on these variations.