CANopen gateway
Wieland Electric GmbH | BA000970 | 11/2016 (Rev. F)
NMT – network management
910835595
The broadcast object NMT is used to start, stop or initialize CANopen devices. A device in the
CANopen network must take on the role of the NMT master for this purpose. This is usually
the PLC. All other devices are regarded as NMT slaves. NMT services are broadcast services to
which the slaves do not generate responses.
All NMT objects start with the CAN-ID 00h.
Broadcast service for an NMT slave with the address N:
Table 84: Network management for an NMT slave with the address N
Broadcast service for all NMT slaves:
Table 85: Network management for all NMT slaves:
80h Go to "Pre-Operational" After booting, an NMT slave will automatically go
into the pre-operational state. In this state,
communication via SDOs is permitted, but not via
PDOs. The NMT slave can be set to this state from
01h Go to "Operational" The operational state is reached from the "pre-
operational" state. Communication via PDOs is
possible in this state and the CANopen slave res-
ponds to sync commands.
During the transition to the NMT operational
state, each slave sends a TxPDO with the transmis-
sion type = 255, so that the NMT master is infor-
med about the current input configuration.
02h Go to "Prepared/Stopped" Communication via SDO or PDO is not possible in
this state and the device also does not respond to
81h Go to "Reset node" This will trigger a re-initialization of the CANopen
function in the NMT slave.
82h Go to "Reset communication" This will trigger a re-initialization of the CANopen
function in the NMT slave; the toggle bit for node
Example for resetting all communication:
The following NMT object (CAN-ID = 00h) contains 2 data bytes (DLC = 2). Data byte 1 con-
tains the command "Reset communication" (82h), data byte 2 addresses this command to all
devices in the CANopen network (address = 0):
Table 86: Example of an NMT object for resetting all communication
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