Schneider Electric DS301 manual Network management services, NMT services for device control

3 Basics IL•1F CANopen DS301

3.6Network management services

Network management (NMT) is part of the CANopen communication profile; it is used to initialize the network and the network devices and to start, stop and monitor the network devices in network mode.

NMT services are executed in a master-slave relationship. The NMT master addresses individual NMT slaves via their node address. A mes- sage with node address "0" is directed to all NMT slaves simultaneously.

NMT-	NMT-	NMT-	NMT-
Slave	Master	Slave	Slave
COB-ID	data
CAN
NMT-		NMT-
Slave		Slave

Figure 3.28 NMT services via the master-slave relationship

The device can only take on the function of an NMT slave.

NMT services NMT services can be divided into two groups:

•Services for device control, to initialize devices for CANopen com- munication and to control the behavior of devices in network mode

•Services:for connection monitoring

3.6.1NMT services for device control

NMT state machine The NMT state machine describes the initialization and states of an NMT slave in mains operation.

		Power on
Reset	Reset	Initialization
Application	Communication
D	E	Pre-Operational		SDO, EMCY
				NMT
		B	C	NMT
		Stopped
				A
		Operational		PDO, SDO, SYNC
				EMCY, NMT

Figure 3.29 NMT state machine and available communication objects

To the right, the graphic shows all communication objects that can be used in the specific network state.

0198441113586, V2.01, 11.2008

46 Fieldbus interface