Controller States Description

Introduction

This section provides a detailed description of the controller states.

 WARNING
UNINTENDED EQUIPMENT OPERATION
  • Never 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.
  • Before performing any of these operations, consider the effect on all connected equipment.
  • Before acting on a controller, always positively confirm the controller state by viewing its LEDs, confirming the condition of the Run/Stop input, verifying the presence of output forcing, and reviewing the controller status information via EcoStruxure Machine Expert.(1)
Failure to follow these instructions can result in death, serious injury, or equipment damage.

(1) The controller states can be read in the PLC_R.i_wStatus system variable of the M241 PLCSystem library.

Controller States Table

The following table describes the controller states:

Controller State

Description

LED

RUN

(Green)

ERR

(Red)

I/O

(Red)

BOOTING

The controller executes the boot firmware and its own internal self-tests. It then checks the checksum of the firmware and user applications.

OFF

OFF

ON

OFF

ON

ON

OFF

ON

OFF

INVALID_OS

There is not a valid firmware file present in the non-volatile memory. The controller does not execute the application. Refer to Firmware Management to restore a correct state.

OFF

Regular flash

OFF

EMPTY

The controller has no application.

OFF

Single flash

OFF

EMPTY after a system error detected

This state is the same as the other EMPTY state. However the application is present, and is intentionally not loaded. A reboot (power cycle), or a new application download, restores a correct state.

OFF

Fast flash

OFF

RUNNING

The controller is executing a valid application.

ON

OFF

OFF

RUNNING with breakpoint

This state is same as the RUNNING state with the following exceptions:

  • The task-processing portion of the program does not resume until the breakpoint is cleared.

  • The LED indications are different.

For more information on breakpoint management, refer to EcoStruxure Machine Expert Programming Guide.

Single flash

OFF

OFF

RUNNING with external error detected

The controller is executing a valid application and a configuration, TM3, SD card, or other I/O error is detected.

When I/O LED is ON, the details about the detected error can be found in PLC_R.i_lwSystemFault_1 and PLC_R.i_lwSystemFault_2. Any of the detected error conditions reported by these variables cause the I/O LED to be ON.

ON

OFF

ON

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.

Regular flash

OFF

OFF

STOPPED with external error detected

The controller is executing a valid application and a configuration, TM3, SD card, or other I/O error is detected.

Regular flash

OFF

ON

HALT

The controller stops executing the application because it has detected an application error.

Regular flash

ON

–

Boot Application not saved

The controller has an application in memory that differs from the application in non-volatile memory. At next power cycle, the application will be changed by the one from non-volatile memory.

ON or regular flash

Single flash

OFF

This timing diagram shows the difference between the fast flash, regular flash and single flash:

Details of the STOPPED State

The following statements are true for the STOPPED state:

  • The input configured as the Run/Stop input remains operational.

  • The output configured as the Alarm output remains operational and goes to a value of 0.

  • Ethernet, 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.

  • All outputs initially assume their configured default state (Keep current values or Set all outputs to default) or the state dictated by output forcing if used. For output used by a PTO function, the default value is ignored, in order not to generate an extra pulse. The subsequent state of the outputs depends on the value of the Update IO while in stop setting and on commands received from remote devices.

Task and I/O Behavior When Update IO While In Stop Is Selected

When the Update IO while in stop setting is selected:

  • The Read Inputs operation continues normally. The physical inputs are read and then written to the %I input memory variables.

  • The Task Processing operation is not executed.

  • The Write Outputs operation continues. The %Q output memory variables are 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 cease operating. For example, a counter will be stopped.

    - If Keep current values configuration is selected:

    PTO, PWM, FreqGen (frequency generator), and HSC reflex outputs are set to 0.

    - If Set all outputs to default configuration is selected:

    PTO outputs are set to 0.

    PWM, FreqGen (frequency generator) and HSC reflex outputs are set to the configured default values.

CAN Behavior When Update IO While In Stop Is Selected

The following is true for the CAN buses when the Update IO while in stop setting is selected:

  • The CAN bus remains operational. Devices on the CAN bus continue to perceive the presence of a functional CAN Master.

  • TPDO and RPDO continue to be exchanged.

  • The optional SDO, if configured, continue to be exchanged.

  • The Heartbeat and Node Guarding functions, if configured, continue to operate.

  • If the Behaviour for outputs in Stop field is set to Keep current values, the TPDOs continue to be issued with the last values.

  • If the Behaviour for outputs in Stop field is Set all outputs to default the last values are updated to the default values and subsequent TPDOs are issued with these default values.

Task and I/O Behavior When Update IO While In Stop Is Not Selected

When the Update IO 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:

  • The Read Inputs operation ceases. The %I input memory variables are frozen at their last values.

  • The Task Processing operation is not executed.

  • The 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.

    - If Keep current values configuration is selected:

    PTO, PWM, FreqGen (frequency generator), and HSC reflex outputs are set to 0.

    - If Set all outputs to default configuration is selected:

    PTO outputs are set to 0.

    PWM, FreqGen (frequency generator), and HSC reflex outputs are set to the configured default values.

CAN Behavior When Update IO While In Stop Is Not Selected

The following is true for the CAN buses when the Update IO while in stop setting is not selected:

  • The CAN Master ceases communications. Devices on the CAN bus assume their configured fallback states.

  • TPDO and RPDO exchanges cease.

  • Optional SDO, if configured, exchanges cease.

  • The Heartbeat and Node Guarding functions, if configured, stop.

  • The current or default values, as appropriate, are written to the TPDOs and sent once before stopping the CAN Master.