Intelligent Motion Systems DSP-402 manual Objects and the Object Dictionary, Trajectory Generator

Trajectory Generator

The chosen operation mode and the corresponding parameters (objects) define the input of the Trajectory Generator. The Trajectory Generator supplies the control loop(s) with the demand values. They are generally mode specific.

Each Mode may use its own Trajectory Generator. A general description of its functionality is given in Section X, which is related to the Profile Position Mode.

Objects and the Object Dictionary

In a CANopen network, a device is controlled by writing to device parameters and reading the status of the device. This is accomplished using a pre-defined dictionary of instructions that can be written and status information that can be read. These pieces of information are called Objects.

The full set of objects are called the Object Dictionary. The Object Dictionary is the interface between the CANopen master, or controller and the MDrivePlus node on a CANopen network.

CAN

Contoller

Output (LED, Relay)

Input (Switch, Sensor)

Analog Input

Additional System Nodes

MDrivePlus Node

Object Dictionary

I/O	Drive	Motor
	Logic

Figure 1.4: MDrivePlus CANopen Object Dictionary

Entries within the Object Dictionary are addressed using 16-bit Indexes. In the case of simple variables (VAR) the index refer- ences the value of the variable directly. In the case of records and arrays the index addresses the entire data structure.

To allow individual elements of the data structures a sub-index is defined. The fields accessed by the sub-index may be of dif- fering data types.

Index (hex)		Object
0000		Not Used
0001	– 004F	Static Data Types
0020	– 003F	Complex Data Types
0040	– 005F	Manufacturer Specific Data
0060	– 007F	Device Profile Specific Static Data Types
0080	– 009F	Device Profile Specific Complex Data Types
00A0 – 0FFF		Reserved for Future Use
1000	– 1FFF	Communications Profile Area
2000	– 5FFF	Manufacturer Specific Profile
6000	– 9FFF	Standardized Device Profile
A000 – BFFF		Standardized Interface Profile
C000 – FFFF		Reserved for Future Use

Table 1.1: Object Dictionary

Part 2: DSP-402 Implementation