Object Dictionary; Dictionary Structure; Data Type; Basic Types - WEG CFW-11 Communications Manual

4 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:
Index
0001h – 0360h Data type definition
1000h – 1FFFh Communication objects
2000h – 5FFFh Manufacturer specific objects
6000h – 9FFFh Standardized device objects
The other indexes that are not referred in this list are reserved for future use.

4.1 Dictionary Structure

The general structure of the dictionary has the following format:
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.

4.2 Data Type

The first part of the object dictionary (index 0001h - 0360h) 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.

4.2.1 Basic Types

The following basic data types are supported:
Integer with sign: There are three types of integers with sign supported by the CFW-11, INTEGER8,
INTEGER16 and INTEGER32, which represent respectively integers with 8, 16 and 32 data bits. Integers with
sign are calculated using two's complement, and in a CAN telegram the least significant byte is always
transmitted first.
Integer without sign: There are three types of integers without sign supported by the CFW-11,
UNSIGNED8, UNSIGNED16 and UNSIGNED32, which represent respectively integers with 8, 16 and 32 data
bits. Also the least significant byte is always transmitted first.
Table 4.1 - Object dictionary groupings
Objects
Used as reference for the data type supported by the system.
They are objects common to all the CANopen devices. They
contain general information about the equipment and also data
for the communication configuration.
In this range, each CANopen equipment manufacturer is free to
define which data those objects will represent.
This range is reserved to objects that describe the behavior of
similar equipment, regardless of the manufacturer.
Index Object
Description
Name Type Access