Nmt Messages - Curtis 1353 User Manual

Curtis 1353 CANopen Expansion Module Manual – June 2017
These types and values comply with the CANopen spec and are used to invoke standard transfer or
information across the CANbus.
Identifiers built using standard message types consist of three fields. The four upper bits hold the
message type. The Node ID is in the bottom 7 bits.
Below is the CANopen-compliant Curtis standard organization of the COB-ID.
NMT messages have the highest priority of the standard message types, and the heartbeat has the
lowest priority.

NMT MESSAGES

NMT (Network Management Transmission) messages are the highest priority message available. The
NMT message puts the 1353 into a specific device state. These messages have 2 bytes of data sent by
the master; the slave does not respond with any data to an NMT.
The 1353 state value can be queried over the CANbus using an SDO. The device state value is also
transmitted with each heartbeat message.
The NMT message identifier consists of the standard message type, NMT, in the top four bits. The
bottom seven bits must be set to zero.
The first data byte of the NMT command is the command specifier. The 1353 will respond to the
following commands.
The second byte of the NMT command defines whether this NMT is for all slaves on the bus (data
byte = 0x00) or for a specific node (data byte = Node ID of the 1353).
pg. 18
11 10 9 8 7 6
Message Type
Value Device State
0 Initialization (or "boot-up")
4 Stopped
5 Operational
127 Pre-Operational
Value Command Specifier
0x01 Enter the Operational state
0x02 Enter the Stopped state
0x80 Enter the Pre-Operational state
0x81 Reset the 1353 (warm boot)
0x82 Reset the CANbus
5 4 3 2 1
Node ID
3 — CANOPEN COMMUNICATIONS
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