3 — CANOPEN COMMUNICATIONS
Curtis 1353 CANopen Expansion Module Manual – June 2017 Return to TOC
pg. 18
ese types and values comply with the CANopen spec and are used to invoke standard transfer or
information across the CANbus.
Identiers built using standard message types consist of three elds. e four upper bits hold the
message type. e Node ID is in the bottom 7 bits.
Below is the CANopen-compliant Curtis standard organization of the COB-ID.
11 10 9 8 7 6 5 4 3 2 1
Message Type Node 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. e
NMT message puts the 1353 into a specic device state. ese messages have 2 bytes of data sent by
the master; the slave does not respond with any data to an NMT.
e 1353 state value can be queried over the CANbus using an SDO. e device state value is also
transmitted with each heartbeat message.
Value Device State
0 Initialization (or “boot-up”)
4 Stopped
5 Operational
127 Pre-Operational
e NMT message identier consists of the standard message type, NMT, in the top four bits. e
bottom seven bits must be set to zero.
e rst data byte of the NMT command is the command specier. e 1353 will respond to the
following commands.
Value Command Specier
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
e second byte of the NMT command denes whether this NMT is for all slaves on the bus (data
byte = 0x00) or for a specic node (data byte = Node ID of the 1353).
To Next Page
Loading...
Need help?
General
