Node Protection (Nmt Node Guarding) - INVT Goodrive350 Series Operation Manual

Communication extension card
COB-ID
0x000

3.4.4 Node protection (NMT Node Guarding)

By using the node protection service, the NMT master node can detect the current state of
each node.

Command
Request: Master station (remote frame) –> slave station
COB-ID
0x700 + Node-ID
Response: Slave station -> master station
COB-ID
0x700 + Node-ID

Description
The most significant bit (MSB) bit 7 of Byte0 (state value) in the response command is the
triggering bit, that is, the value of bit 7 is alternated between 0 and 1 each time when the slave
station transmits a response frame to distinguish frames. Bits 0 to 6 indicate the state of the
slave station. Table 3-5 describes the state values and their corresponding state.
State value (Byte0: Bits 0–6)

Example
For example, the command for the master station to detect the state of slave station 3.
Master station (remote frame) -> slave station
COB-ID
0x703
After receiving the node protection command transmitted by the master station, the slave
station transmits the following command response to the master station.
COB-ID
0x703
In the command, bit 7 of Byte0 is 1, and the state value is 0×05, indicating that slave station 3
is in the operation state. If receiving another node protection command, the slave station
transmits a command frame in which the state value is 0×05 to the master station, and the
Table 3-5 State values and their corresponding states
0x00
0x04
0x05
0x7F
Byte0
0x01
No data
Byte0 (state value)
Bit 7: Triggering bit; Bits 0 to 6: State
Pre-operational
No data
/
Byte0 (state value)
0x85
-22-
CANopen communication card
Byte1
0x00
State
Initializing
Stopped
Operation