Basic of CAN
Parameter manual
b maXX
®
1000
Document no. 5.07004.03
Baumüller Nürnberg GmbH
172
B.3
Object directory
The central element of every CANopen device is its object directory CANopen-device
CANopen differentiates between 4 types of messages
m
Administrative messages ( e.g. network-management NMT)
m
Service data (SDO)
m
Process data (PDO)
m
Predefined messages (e.g. synchronization, emergency)
n
NMT
The communication states of the device are controlled and monitored by means of the network manage-
ment services.
n
SDO
SDO are used for the transfer of greater volume of the service data (data with low priority) in addition, data
volumes of 4 bytes maximum are transmitted with one SDO in the bmaxx1000. SDOs are used for device
configuration, transmitted asynchronous and accepted by the receiver. All entries in the object directory
can be accessed by means of SDOs:
n
PDO
The function of PDOs is the exchange of process data (data with high priority). PDOs can be transmitted
both synchronously and asynchronous. They have broadcast character and are not confirmed by the re-
ceiver.
Synchronous means that transmission depends on the synchronization object.
Index (hex)
Object
0000
hex
Not used
0001
hex
– 001F
hex
Static data types
0020
hex
– 003F
hex
Complex data types
0040
hex
– 005F
hex
Manufacturer-specific data types
0060
hex
– 007F
hex
Device profile-specific static data types
0080
hex
– 009F
hex
Device profile-specific dynamic data types
00A0
hex
– 0FFF
hex
Reserved
1000
hex
– 1FFF
hex
Range for the communication profile
2000
hex
– 5FFF
hex
Range for manufacturer-specific objects
6000
hex
– 9FFF
hex
Range for the device profile
A000
hex
– AFFF
hex
Reserved