Elevator Core CANopen Network Management (NMT)
The network management (NMT) service is used to control NMT states of CANopen devices.
An NMT message is a 2-byte CAN frame with COB-ID 0 (000h).
The first byte contains a command specifier which indicates an NMT command.
The second byte contains a Node-ID of a target device
If the node-ID is 0, the message is a global message to all devices on the CANopen network.
Following a Power ON, all CANopen devices will enter the initialisation state. Following completion of the initialisation, the device will switch to pre-operational state and transmit an emergency message to announce the completion of initialisation and availability on the network. In this state, the SDO telegram may be used to configure the node as required, and PDO communication is disabled. The NMT telegram is then used by the Network Controller to switch the device into operational state when configured and ready to operate.
The NMT message has the following format:
COB-ID | NMT Command | Target Node ID |
|---|---|---|
0x0000 | 1 Byte | 1 Byte |
Note
The NMT telegram always has COB-ID 0x0000
If the target Node-ID is 0x00, the message is intended for all connected nodes.
The drive supports the following Network Management commands.
NMT Command | Function | Target Node State Transition |
|---|---|---|
0x01 | Start Remote Node | Pre-Operational to Operational |
0x02 | Stop Remote Node | Any Sate to Stopped |
0x80 | Enter Pre-Operational | Operational to Pre-Operational |
0x81 | Reset Node | Any State to Initialisation followed by Pre-Operational |
0x82 | Reset Node Communication | Any State to Initialisation followed by Pre-Operational |