Current State

Off

The node is switched off.

Initializing

The node is initialized.

Reset application

The parameters of the application are reset to their default values.

Reset communication

The parameters of the communication profile are reset to their default values.

Reset configuration

The node is configured with the parameter set that is stored in the object directory. Communication via the fieldbus interface can start.

Not active

First state after the initialization phase. The node starts to monitor the fieldbus and analyze the received frames.

If valid frames are received within a defined timeout period, the node switches to the basic Ethernet state.

Basic Ethernet

After connection to the fieldbus, the node did not receive any valid frames within a defined timeout period. In this state, no bus cycle is available but the node can perform a legacy Ethernet communication. As soon as a valid frame is received, the node switches to the operational state.

INFORMATION: The node can send frames independently only in this state. In all other states, permission from the master (MN (Managing Node)) is required to send frames.

Pre-operational 1

First state within a valid bus cycle. The master starts to configure the node. Once the node has detected an SoC frame (Start of Cycle) on the fieldbus, it switches to the pre-operational 2 state.

Pre-operational 2

The node receives the SoC frames cyclically. In this state, the master continues to configure the node. As soon as the master has received the response frame of the node, the node switches to the operational state.

If a communication error is detected, e.g. the frames are lost, the node switches back to the pre-operational 1 state.

Ready to operate

The node signals to the master that it is configured and waits for the command to switch to the operating state.

Operational

The node is configured and cyclic process data exchange starts.

Stopped

The node has received the NMT_StopNode command during a valid bus cycle. In this state, the node is still part of a valid bus cycle but process data is not exchanged.

When the node receives the NMT_EnterPreoperational2 command, it switches back to pre-operational 2 state.