254 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS23x, 34x, 43x
10.7 More details of CANopen Theory
10.7.6 NMT (Network Management services)
The Network Management is structured according to nodes and follows a master-slave
structure. NMT objects are used for executing NMT services. Through NMT services,
nodes are initialised, started, monitored, reset or stopped. All nodes are regarded as
NMT slaves. An NMT slave is uniquely identified in the network by its Node-ID. NMT
requires that one device in the network fulfils the function of the NMT master. The NMT
master controls the state of the NMT slaves. The state attribute is one of the values
(Stopped, Pre-operational, Operational, Initialising). The module control services can be
performed with a certain node or with all nodes simultaneously. The NMT master con
-
trols its own NMT state machine via local services which are implementation dependent.
The Module Control Service, except Start Remote Node, can be initiated by the local ap
-
plication.
A general NMT protocol:
Where CS is the NMT command specified. The Node-ID of the NMT slave is assigned
by the NMT master in the Node Connect protocol, or 0. If 0, the protocol addresses all
NMT slaves.
Start Remote Node:
This is an instruction for transition from the Pre-Operational to Operational communi-
cations state. The drive can only send and receive process data when it is in the Opera-
tional state.
Stop Remote Node:
This is an instruction for transition from either Pre-Operational to stopped or from Op-
erational to Stopped. In the stopped state, the nodes can only process NMT instructions.
Enter Pre Operational:
This is an instruction for transition from either Operational or Stopped state to Pre-Op-
erational. In the Pre-Operational state, the node cannot process any PDOs. However, it
can be parameterized or operated via SDO. This means set point can also be entered.
CS = Operation
1 Start Remote Node
2 Stop Remote Node
128 Enter Pre Operational
129 Reset Node
130 Reset Communication
TT1081GB
Request
COB-ID = 0
CS Node-ID
NMT Slave (s)
Indicatio
Indicatio
Indicatio
01
2
NMT master
TT1082GB
To Next Page
Loading...
Need help?
General
