HMI Controller States Description
This section provides a detailed description of the controller states.
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UNINTENDED EQUIPMENT OPERATION |
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oNever assume that your controller is in a certain controller state before commanding a change of state, configuring your controller options, uploading a program, or modifying the physical configuration of the controller and its connected equipment. oBefore performing any of these operations, consider the effect on all connected equipment. oBefore acting on a controller, always positively confirm the controller state by verifying the presence of output forcing, and reviewing the controller status information via SoMachine (1). |
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Failure to follow these instructions can result in death, serious injury, or equipment damage. |
(1) Note: The controller states can be read in the PLC_R.i_wStatus system variable of the PLCSystem library.
This table describes the controller states:
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Controller State |
Description |
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BOOTING |
The controller executes the boot firmware and its own internal self-tests. It then checks the checksum of the firmware and user applications. It does not execute the application nor does it communicate. |
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INVALID_OS |
There is not a valid firmware file present in the Flash memory. The controller does not execute the application. Communication is only possible through the USB host port, and then only for uploading a valid OS. |
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EMPTY |
There is no application in memory or the application is invalid. |
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RUNNING |
The controller is executing a valid application. |
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RUNNING with Breakpoint |
This state is the same as the RUNNING state with the following exceptions: oThe task-processing portion of the program does not resume until the breakpoint is cleared. For more information, refer to breakpoints management. |
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RUNNING with detection of an External Error |
This state is the same as the normal RUNNING state. |
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STOPPED |
The controller has a valid application that is stopped. See Details of the STOPPED State for an explanation of the behavior of outputs and field buses in this state. |
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STOPPED with detection of an External Error |
This state is the same as the normal STOPPED state. |
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HALT |
The controller stops executing the application because it has detected an Application or a System Error. This description is the same as for the STOPPED state with the following exceptions: oThe task responsible for the Application Error always behaves as if the Update I/O while in stop option was not selected. All other tasks follow the actual setting. |
The following statements are always true for the STOPPED state:
oThe input configured as the Run/Stop input remains operational.
oEthernet, Serial (Modbus, ASCII, and so on), and USB communication services remain operational and commands written by these services can continue to affect the application, the controller state, and the memory variables.
oAll outputs initially assume their configured state (Keep current values or Set all outputs to default) or the state dictated by output forcing if used. The subsequent state of the outputs depends on the value of the Update I/O while in stop setting and on commands received from remote devices.
Task and I/O Behavior When Update I/O While In Stop Is Selected
When the Update I/O while in stop setting is selected:
oThe Read Inputs operation continues normally. The physical inputs are read and then written to the %I input memory variable.
oThe Task Processing operation is not executed.
oThe Write Outputs operation continues. The %Q output memory variable is updated to reflect either the Keep current values configuration or the Set all outputs to default configuration, adjusted for any output forcing, and then written to the physical outputs.
NOTE: Expert functions continue to operate. For example, a counter will continue to count. However, these Expert functions do not affect the state of the outputs. The outputs of Expert I/O conform to the behavior stated here.
NOTE: Commands received by Ethernet, Serial, USB, and CAN communications can continue to write to the memory variables. Changes to the %Q output memory variables are written to the physical outputs.
CAN Behavior When Update I/O While In Stop Is Selected
The following is true for the CAN buses when the Update I/O while in stop setting is selected:
oThe CAN bus remains fully operational. Devices on the CAN bus continue to perceive the presence of a functional CAN Master.
oTPDO and RPDO continue to be exchanged.
oThe optional SDO, if configured, continue to be exchanged.
oThe Heartbeat and Node Guarding functions, if configured, continue to operate.
oIf the Behavior for outputs in Stop field is set to Keep current values, the TPDOs continue to be issued with the last actual values.
oIf the Behavior for outputs in Stop field is Set all outputs to default the last actual values are updated to the default values and subsequent TPDOs are issued with these default values.
Task and I/O Behavior When Update I/O While In Stop Is Not Selected
When the Update I/O while in stop setting is not selected, the controller sets the I/O to either the Keep current values or Set all outputs to default condition (as adjusted for output forcing if used). After this, the following becomes true:
oThe Read Inputs operation ceases. The %I input memory variable is frozen at its last values.
oThe Task Processing operation is not executed.
oThe Write Outputs operation ceases. The %Q output memory variables can be updated via the Ethernet, Serial, and USB connections. However, the physical outputs are unaffected and retain the state specified by the configuration options.
NOTE: Expert functions cease operating. For example, a counter will be stopped.
CAN Behavior When Update I/O While In Stop Is Not Selected
The following is true for the CAN buses when the Update I/O while in stop setting is not selected:
oThe CAN Master ceases communications. Devices on the CAN bus assume their configured fallback states.
oTPDO and RPDO exchanges cease.
oOptional SDO, if configured, exchanges cease.
oThe Heartbeat and Node Guarding functions, if configured, stop.
oThe current or default values, as appropriate, are written to the TPDOs and sent once before stopping the CAN Master.
