DSP resolver user manual
User Manual
Version 1.15
8.
CANOPEN MANUAL AND SUPPORTED DS301 SPECIFIC OBJECTS
CANopen is a CAN-based higher layer protocol. It was developed as a standardized
embedded network with highly flexible configuration capabilities. CANopen was designed
for motion-oriented machine control networks, such as handling systems. By now it is used
in many various fields. Standardized profiles developed by CiA members simplify the
system designer's job of integrating a CANopen network system. CANopen is flexible and
open enough to enable manufacturer-specific functionality in devices, which can be added to
the generic functionality described in the profiles.
CANopen provides standardized communication objects for real-time data transfers
(Process Data Objects, PDO), configuration data (Service Data Objects, SDO), and special
functions (Time Stamp, Sync message, and Emergency message) as well as network
management data (Boot-up message, NMT message, and Error Control).
8.1
Object dictionary
The object dictionary represents the complete access to the application program of the
device in terms of application data as well as in term of configuration parameters. The
object dictionary gain access to data types used in the device, the communication
parameters and the application data and configuration parameters. The object dictionary is
indexed table where an index may contain also subindexes. The object dictionary is divided
in the following segments:
•
0x1000 – 0x1FFF
Communication object area
•
0x2000 – 0x5FFF
Manufacturer specific area
•
0x6000 – 0x9FFF
Device profile specific area
•
0xA000 – 0xBFFF
Interface profile specific area
•
0xC000 – 0xFFFF
Reserved
8.2
Network management (NMT)
A NMT message is mapped to a single CAN frame with the data length of 2 bytes. Its
identifier (CAN ID) is always 0. The first byte contains the command specifier and the
second contains the Node ID of the device that must perform the command (in the case of
Node ID 0 all nodes have to perform the command). The NMT message transmitted by the
NMT master forces the nodes to transit to another NMT state. The CANopen state machine
specifies the states:
•
Initialization
•
Pre-Operational
•
Operational
•
Stopped
After power-on, each CANopen device is in the state
Initialization
and automatically transits
to the state
Pre-operational
. In
Pre-operational
state module may transmit and receive
SDOs. Nodes, that the NMT master has set into the state
Operational
, are also allowed to
transmit and receive PDOs. In the state
Stopped
no communication is allowed excluding the
NMT messages.
The state
Initialization
is divided into three sub-states in order to enable a complete or
partial reset of a node. In the sub-state
Reset
Application the parameters of the
manufacturer-specific profile area and the standardized device profile area are set to their
power-on values. In the sub-state
Reset Communication
the parameters of the
communication profile area are set to their power-on values. The third sub-state is
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