OBJECT DICTIONARY
7 OBJECT DICTIONARY
The object dictionary is a list containing several equipment data which can be accessed via CANopen network. An
object of this list is identified by means of a 16-bit index, and it is based in that list that all the data exchange between
devices is performed.
The CiA DS 301 document defines a set of minimum objects that every CANopen network slave must have. The
objects available in that list are grouped according to the type of function they execute. The objects are arranged in
the dictionary in the following manner:
Table 7.1:
Object dictionary groupings
Index
Objects
Description
0001h - 025Fh
Data type definition
Used as reference for the data type supported by the system.
1000h - 1FFFh
Communication objects
They are objects common to all the CANopen devices.
They
contain general information about the equipment and also data for the
communication configuration.
2000h – 5FFFh
Manufacturer specific objects
In this range, each CANopen equipment manufacturer is free to define
which data those objects will represent.
6000h – 9FFFh
Standardized device objects
This range is reserved to objects that describe the behavior of similar
equipment, regardless of the manufacturer.
The other indexes that are not referred in this list are reserved for future use.
7.1 DICTIONARY STRUCTRE
The general structure of the dictionary has the following format:
Index
Object
Name
Type
Access
Index:
indicates directly the object index in the dictionary.
Object:
describes which information the index stores (simple variable, array, record, etc.).
Name:
contains the name of the object in order to facilitate its identification.
Type:
indicates directly the stored data type. For simple variables, this type may be an integer, a float, etc. For
arrays, it indicates the type of data contained in the array. For records, it indicates the record format according
to the types described in the first part of the object dictionary (indexes 0001h – 0360h).
Access:
informs if the object in question is accessible only for reading (ro), for reading and writing (rw), or if it is
a constant (const).
For objects of the array or record type, a sub-index that is not described in the dictionary structure is also necessary.
7.2 DATA TYPE
The first part of the object dictionary (index 0001h – 025Fh) describes the data types that can be accessed at a
CANopen network device. They can be basic types, as integers and floats, or compound types formed by a set of
entries, as records and arrays.
7.3 COMMUNICATION PROFILE - COMMUNICATION OBJECTS
The indexes from 1000h to 1FFFh in the object dictionary correspond to the part responsible for the CANopen network
communication configuration. Those objects are common to all the devices, however only a few are obligatory. A list
with the objects of this range that are supported by the soft-starter SSW900 is presented next.
SSW900 | 21
