BECKHOFF AX2000 CANopen communication profile - Manual (Page 18)

3.3.3 Extended data types
Extended data types are derived from basic data types and mixed data types. The types of exten-
ded data that are supported are defined below.
3.3.3.1 Octet String
The data type OCTET_STRING is defined with the data type ARRAY. Length is the length of the
octet string.
ARRAY[length] OF UNSIGNED8 OCTET_STRINGlength
3.3.3.2 Visible String
The data type VISIBLE_STRING can be defined with the data type UNSIGNED8 or the data type
ARRAY. Permissible values are 00
h
and the range from 20
h
to 7E
h
. The data are interpreted as 7
bit ASCII code (as per ISO 646-1973(E)). Length is the length of the visible string.
UNSIGNED8 VISIBLE_CHAR
ARRAY[length] OF VISIBLE_CHAR VISIBLE_STRINGlength
3.4 Communication Objects
Communication Objects are described with the help of service elements and protocols. Two basic
types of service elements are distinguished:
l Unconfirmed services
l Confirmed services
All services require faultless operation of the Data Link and Physical Layer.
AX2000/2500 supports Communication Objects that are described in detail in the following sections:
l Network Management Objects (NMT)
l Synchronization Object (SYNC)
l Time Stamp Object (TIME)
l Emergency Object (EMCY)
l Process Data Object (PDO)
l Service Data Object (SDO)
l Nodeguard
18 CANopen for AX2000/2500
CANopen communication profile
07/2007
BECKHOFF