
Manual_GXP5_417_Lift_EN.doc
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Baumer IVO GmbH & Co. KG
04.05.11
Villingen-Schwenningen,
Germany
3.4. CANopen
communication
3.4.1. Communication profile
The communication between the network nodes and the master (PC/controller) is carried out via object
directories and objects. The objects are addressed via a 16-bit index. The CANopen communication profile
DS 301 standardizes the various communication objects. Accordingly, they are divided into several groups:
• Process data objects (PDO) for the real-time transmission of process data
• Service data objects (SDO) for the write and read access to the object directory
• Objects for the synchronization and error display of CAN nodes:
SYNC object (synchronization object) for the synchronization of network nodes
EMCY object (emergency object) for the error display of a device or its periphery
• Network management (NMT) for the initialization and network control
• Layer setting services (LSS) for the configuration by means of a serial number, revision number etc. within
an
existing network
3.4.2. CANopen message structure
The first part of a message is the COB-ID (identifier).
Structure of the 11-bit COB-ID:
Function Code
Node-ID
4-bit Function Code
7-bit Node-ID
The function code provides information on the type of message and the priority
The lower the COB-ID, the higher the priority of the message.
Broadcast messages:
Function Code
COB-ID
NMT 0
SYNC 80h
Peer to peer messages:
Function Code
COB-ID
Emergency
80h + Node-ID
PDO1 (tx)
1)
17Bh+ Lift number * 10 + PosUnit
SDO (tx)
1)
580h + Node-ID
SDO (rx)
1)
600h + Node-ID
Heartbeat
700h + Node-ID
LSS (tx)
1)
7E4h
LSS (rx)
1)
7E5h
1): (tx) and (rx) from the
standpoint of the encoder
The node ID can be freely selected via the CANopen bus between 1 and 127 (if rotary switch = 0). The
encoders are shipped with a node ID = 1.
A change is made with the service data object 2101h or via LSS.
A CAN telegram consists of the COB-ID and up to 8 bytes of data:
COB-ID DLC
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Xxx x xx xx xx xx xx xx xx xx
The exact telegrams will be listed in detail later.