Manuale d’uso - MCM260X - 45
11.a CAN Application Layer (CAL)
COB-ID Description
0 NMT start/stop services
1..220 CMS priority object 0
221..440 CMS priority object 1
441..660 CMS priority object 2
661..880 CMS priority object 3
881..1100 CMS priority object 4
1101..1320 CMS priority object 5
1321..1540 CMS priority object 6
1541..1760 CMS priority object 7
1761..2015 NMT Node Guarding
2016..2031 NMT, LMT, DBT services
CAL does not define the content of the CMS objects; it defines how but not what. CANopen provides
the implementation of a system control distributed using the CAL protocols and services.
11.1 Object Dictionary
The Object dictionary is fundamental for a CANopen device. All the data and information regarding
the configuration are saved in it. It is an orderly group of objects, where each is addressed by a 16 bit
ID. The object dictionary is divided into 3 areas, where each area is represented by a table that lists all
of its objects:
Communication Profile Area (0x1000-0x1FFF addresses): contains all the fundamental communication
parameters and is common to all the CANopen devices.
Manufacturer Specific Profile Area (0x2000-0x5FFF address): in this area each manufacturer may
implement its specific functionalities.
Standardized Device Profile Area (0x6000-0x9FFF addresses): defines the input/output transmission/
reception modes. It is defined by the DS-401 standard (Device Profile for I/O devices)
In the object dictionary, an addressing scheme is used to
access the device parameters, communication, functions and data. Each address is defined by a 16 bit
number that indicates the address row of the table. A maximum of 65536 addresses are permitted.
If an object is composed of several elements, these are
identified by means of sub-indexes. Each sub-index indicates the
individual column address of the object, allowing a maximum of 256 sub-indexes.
If the address consists of simple variables (8bit unsigned, 16bit unsigned,
etc.), the sub-index is always zero. For the other objects, such as arrays, records, etc., sub-index 0 will
indicate the
maximum number of sub-indexes of the object.
Data is coded in the following sub-indexes:
• object name describing the functions
• a data type attribute
• an access attribute: read only, write only or read/write
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