The most important part of a POWERLINK profile is the POWERLINK Object Dictionary. The POWERLINK Object Dictionary is essentially a grouping of POWERLINK Objects accessible via the network in an ordered, pre-defined fashion. Each object within the dictionary is addressed using a 16-bit index.
The overall layout of the standard POWERLINK Object Dictionary is shown by Table 8. This layout closely conforms to other industrial serial bus system concepts.
The POWERLINK Object Dictionary may contain a maximum of 65536 entries which are addressed through a 16-bit index.
The Static Data Types at indices 0001h through 001Fh contain type definitions for standard data types like BOOLEAN, INTEGER, floating point, string, etc. These entries are included for reference only; they cannot be read or written.
Table 8 – POWERLINK Object Dictionary structure
|0001h .. 001Fh||Static Data Types|
|0020h .. 003Fh||Complex Data Types|
|0040h .. 005Fh||Manufacturer Specific Complex Data Types|
|0060h .. 007Fh||Device Profile Specific Static Data Types|
|0080h .. 009Fh||Device Profile Specific Complex Data Types|
|00A0h .. 03FFh||Reserved for further use|
|0400h – 041Fh||POWERLINK Specific Static Data Types|
|0420h – 04FFh||POWERLINK Specific Complex Data Types|
|0500h .. 0FFFh||Reserved for further use|
|1000h .. 1FFFh||Communication Profile Area|
|2000h .. 5FFFh||Manufacturer Specific Profile Area|
|6000h .. 9FFFh||Standardised Device Profile Area|
|A000h .. BFFFh||Standardised Interface Profile Area|
|C000h .. FFFFh||Reserved for further use|
Complex Data Types at indices 0020h through 003Fh are pre-defined structures that are composed of standard data types and are common to all devices.
Manufacturer Specific Complex Data Types at indices 0040h through 005Fh are structures composed of standard data types but are specific to a particular device.
Device Profiles may define additional data types specific to their device type. The static data types defined by the device profile are listed at indices 0060h - 007Fh, the complex data types at indices 0080h - 009Fh.
A device may optionally provide the structure of the supported complex data types (indices 0020h - 005Fh and 0080h - 009Fh) at read access to the corresponding index. Sub-Index 0 provides the number of entries at this index, and the following sub-indices contain the data type encoded as UNSIGNED16 according to 7.1 Primitive DataTypes.
POWERLINK Specific Static Data Types shall be described at indices 0400h – 041Fh. These entries are included for reference only; they cannot be read or written. POWERLINK Specific Complex Data Types shall be described at indices 0420h – 04FFh
The Communication Profile Area at indices 1000h through 1FFFh contains the communication specific parameters for the POWERLINK network. These entries are common to all devices and addressed by this companion specification.