AS Series Operation Manual   
 
  Boot-up services 
After the slave completes the initialization and enters the pre-operational state, it transmits the Boot-
up message. 
1.  Other predefined CANopen communication objects (SYNC and EMCY) 
  SYNC Object (Synchronous object) 
The synchronous object is the message that the master node periodically broadcasts on the CANopen 
network. This object recognizes the network clock signal. Every device decides whether to use the 
event use synchronous communication with other network devices depending on its configuration. For 
example, when controlling a driving device, the devices do not act immediately after they receive the 
command sent by the master. They do act when they receive the synchronous message. This makes 
multiple devices act synchronously. 
The format of the SYNC message: 
  Emergency object 
The emergency object is used by a CANopen device to indicate an internal error. When an emergency 
error occurs in the device, the device sends the emergency message (including the emergency error 
code), and the device enters an error state. After the error is eliminated, the device sends another 
emergency message with emergency error code 0, and the device enters the normal state. 
The format of the emergency message: 
80 (hex) 
+Node-ID 
Emergency error 
code 
Error 
register 
Factory-defined error code 
LSB  MSB 
Note: The value in the error register is mapped to index 1001 (hex) in the object dictionary. If the value is 
0, no error occurred. If the value is 1, a normal error occurred. If the value is H’80, an internal error 
occurred in the device. 
 
10.3.3  The Predefined Connection Set 
In order to decrease the configuration workload of the network, CANopen defines a default identifier. In the 
predefined connection set, the structure of the 11-bit identifier is as follows.