SD710 Series Servo Drive User Manal Chapter 11 Communication
11
0x700 + Node_ID
1
The answer messages returned by the NMT from the node are shown in Table 11-16.
Table 11-16 Node Protection Answer Messages
COB_ID
RTR
Data
0x700 + Node_ID
0
status word
The data segment is a one-byte status word with the data format shown in Table 11-17.
Table 11-17 Data Segment Correspondence Description
Data bit
Description
bit7
Must alternate "0" and "1" each time
bit6
～
0
4: Stop state
5: Operational status
127: Pre-operation status
(2) Heartbeat
The heartbeat model uses a producer-consumer model.
The Canopen device may send heartbeat messages according to the period set by the producer heartbeat interval object
1017h (Unit:ms). A node in the CAN network with consumer heartbeat function monitors this producer according to the
consumer time set by object 1016h and it considers the node to be faulty once the producer heartbeat of the corresponding
node is not received within the consumer heartbeat time range.
After configuring the producer heartbeat interval 1017h, the node heartbeat function activates and starts generating
heartbeat messages. After configuring a valid Sub index for consumer heartbeat 1016h, monitoring starts upon receiving
a frame of heartbeat from the corresponding node.
The master sends a heartbeat messages at its producer time, and the slave monitoring the master considers the master
dropped if it does not receive the heartbeat messages within the object 1016 Sub index time. Object 1016h sub index
time ≥ master producer time × 2, otherwise it causes the slave to mistakenly consider t
he master as dropped.
Each object of the slave sends a heartbeat message at 1017h time, and the master that monitors the slave and does not
receive the heartbeat message within the consumer time is considered to have dropped the slave.
The format of the heartbeat message is shown in Table 11-18.
Table 11-18 Heartbeat Message Format
COB_ID
RTR
Data
0x700 + Node_ID
0
status word
The data segment has only one byte and the highest bit is fixed to "0".
Table 11-19 Data Segment Correspondence Description
Data bit
Description
bit7
Fixed to "0"
bit6 to bit0
4: Stop state
5: Operational status
127: Pre-operation status
11.2.3 Service Data Objects (SDO)
The Service Data Object (SDO) is linked to the object dictionary through object indexes and sub-indexes, through which
the SDO can read the object contents in the object dictionary or modify the object data if allowed.
11.2.3.1 SDO transmission method
The SDO transmission method follows the client-server mode, i.e. the Ask and Answer method, which is similar to the
freedom in serial communication. SDO is initiated by the SDO client in the CAN bus network and answered by the SDO
server. The data exchange between SDO requires at least two CAN messages and the two CAN messages do not
have the same CAN identifier. The transmission is as shown in the following figure.
