ZLIM42C Integrated Open Loop Step Motor Manual Version 1.03
ZLIM42C Integrated Open Loop Step Motor Manual Version 1.03
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Shenzhen ZhongLing Technology Co.,Ltd. TEL: +86-0755-29799302 FAX
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+86-0755-2912 4283 WEB:
SDO protocol is used to operate on the object dictionary and process data with low
real-time performance. Data with high real-time performance requirements is usually
transmitted through PDO.
PDO communication method is based on a Producer / Consumer model. Data is sent
from one device (producer) to another device (consumer) or many other devices
(broadcast), and it is a transmission without acknowledgement, data transfer is limited
to 1 to 8 bytes. CANopen devices receive or send by describing 2 parameters of PDO:
Communication Parameter and Mapping Parameter.
ZLIM42C series driver supports 4 RPDO and 4 TPDO, and describes the communication
parameters and mapping parameters of each PDO communication port according to the
CiA301 subprotocol.
Service Data Object (SDO)
SDO message is mainly used to access the device's object dictionary to configure
devices in a CANopen network. SDO communication method is based on the
Client/Server model, that is, the message sent must be confirmed by the receiver. The
visitor is called Client, and the device where the object dictionary is accessed and
responds to read and write requests is called Server. The protocol stipulates that the
value of the read object dictionary 4ed is called Upload, and the value of the modified
parameter is called Download.
ZLIM42C series driver supports both of fast SDO protocol and ordinary SDO protocol
transmission modes as described in CiA301.
Network Management Object (NMT)
NMT(Network Management) is based on Master / Slaver structure. The master station
can control the state machine of the slave stations through NMT message. After the
CANopen device is powered on or reset, the device will first enter Initialization state.
After the program is initialized, the device will automatically send a Boot-Up message,
and then automatically enter the Pre-Operational state. After that, the slave device
switches between different states according to the NMT message sent by the master.
Synchronization Object (SYNC)
SYNC(Synchronization object) provides a reference clock for the network to synchronize
devices in the network. SYNC belongs to the producer/consumer communication
relationship. SYNC object is sent by a SYNC producer, and all other devices in the
network can receive SYNC. Assuming that all devices in the network support the
synchronous PDO function, user can use SYNC to achieve simultaneous actions of
multiple devices. The COB-ID of SYNC message is 0x80, which has a high priority and
guarantees the normal transmission of SYNC. In addition, the SYNC message can contain
no data to reduce the data amount of SYNC message.
Emergency Object (EMCY)
The device can report its internal fault to CANopen network through the emergency
object EMCY. EMCY belongs to the producer/consumer communication model, and all
devices in the network can consume the message. EMCY message occupies all 8 bytes
of data. Among them, byte 0 and byte 1 are error codes, and the error codes
correspond to various types of errors that occur on the device. Byte 2 is the error
register, whose value is stored in the object dictionary 1001h, and corresponds to
various types of faults that occur in the device. The content of byte 3 to byte 7 is the
error domain defined by the manufacturer, which can be the specific fault type.
Through EMCY object, the master station can easily grasp the specific failure situation
of the slave station.
5.3. Driver control protocol CiA402
5.3.1 CiA402 state machine
CiA402 protocol defines a standard state machine for motion control devices. It also
defines various operating modes and their definitions in the object dictionary.
Standard state machine describes the state of the device and the possible control
sequences of the driver. Each step state represents a specific internal or external
behavior, and the state of the device determines which commands can be received.
