Delta AS Series Operation Manual page 358

A S S e r i e s O p e r a t i o n M a n u a l
Mode 0: The PDO information is transmitted only when the PDO data changes and the synchronous
Modes 1–240: One piece of PDO information is transmitted every 1–240 synchronous signals.
Mode 254: The trigger is defined the manufacturer. The definition in the PLC is the same as mode
Mode 255: The PDO is transmitted when the data changes, or it is transmitted after a trigger.
All the data in the PDO has to be mapped from the object dictionary. The following diagram shows an
example of PDO mapping.
xxxxh
yyyyh
zzzzh
PDO_1
The following table shows the data format for RxPDO and TxPDO.
COB-ID
Object
identifier
2. SDO (service data object)

The SDO builds the client/server relation between two CANopen devices. The client device can read
the data from the object dictionary on the server device and write the data into the object dictionary on
the server device. The SDO visit mode is "client/server" mode. The mode which is visited is the SDO
server. Every CANopen device has at least one service data object that provides the visit channel for
the object dictionary of the device. SDO can read all the objects in the object dictionary, and write all
objects into the object dictionary.

The SDO message contains the index and subindex information used to position the objects in the
object dictionary, and the composite data structure can easily be passed by the SDO visit. After the
SDO client sends the reading/writing request, the SDO server replies. The client and the server can
stop SDO transmission. The requested message and the reply message are separated by different
COB-IDs.
_10

The SDO can transmit the data in any length. If the data length is more than 4 bytes, the data must be
transmitted by segment. The last segment of the data contains an end flag.
1 0 - 1 4
signal is received.
255.
Object dictionary
xxh
Application object A
Application object B
yyh
Application object C
zzh
Application object B
Byte 0 Byte 1 Byte 2
PDO_1 mapping
0
1
2
3
Application object C
Byte 3 Byte 4 Byte 5
Data
3
yyyyh yyh 8
zzzzh zzh 16
xxxxh xxh 8
Application object A
Byte 6 Byte 7