01 ▎Beware! The “Death Trap” of PDO Mapping "Last week, the robotic arms at Tesla's Berlin factory suddenly danced in unison, all because a PDO mapping bit was mistakenly set to 1!" German engineer Hans shared this complaint at a bar in Munich, revealing the most dangerous blind spot in CANopen configuration. # EDS file … Read more
1. Historical Origins of the Two CAN was originally designed by the German company BOSCH for automotive control systems and became an international standard in 1993. Due to its high reliability and good error detection capabilities, it has gained attention and has now expanded into various fields such as medical, transportation, motion control, and … Read more
In the article “CanOpen Message – Understanding PDO Messages“, a brief introduction to PDO messages is provided. For SDO messages, there are read/write identifiers and object indices, allowing the receiving end to recognize the messages. Meanwhile, PDO messages contain only valid data, so for the receiving end to identify them, both the sending and receiving … Read more
1, NMT Messages CANopen devices have three states: pre-operational, operational, and stopped. By default, after startup, they automatically enter the pre-operational state, during which PDO messages cannot be sent. If PDO messages need to be sent, the device must be manually switched to operational (run) state after startup. The following message can be sent to … Read more
1、 NMT Messages 1.1、NMT Module Control Only the NMT-Master node can send NMT ModuleControl messages. All slave devices must support NMT module control services. The NMT Module Control message does not require a response. The NMT message format is as follows: NMT-Master → NMT Slave When Node-ID=0, all NMT slave devices are addressed. CS is … Read more
In the previous article, we briefly introduced the CANopen framework and the seven types of CANopen services. In this article, we will elaborate on the Object Dictionary, SDO, and PDO of CANopen. This series of articles mainly introduces the CANopen protocol, covering topics such as the Object Dictionary, services, SDO, PDO, and master/slave nodes. For … Read more
In the previous article, we introduced the basic knowledge and core concepts of the CANopen protocol. In this article, we will continue to explain the fundamentals of CANopen communication. This series mainly covers the basic content of the CANopen protocol, including the object dictionary, services, SDO, PDO, and master/slave nodes. For CANopen software and hardware … Read more
Disclaimer Any direct or indirect consequences and losses caused by the dissemination and use of the information provided in this article shall be borne by the user. Thunder God Testing and the author of the article shall not bear any responsibility for this. Thunder God Testing reserves the right to modify and explain this article. … Read more
1、CANopenPredefined Connection Set To reduce the configuration workload of simple networks, CANopen defines a mandatory default identifier (CAN-ID) allocation table. These identifiers are available in the pre-operational state and can be modified through dynamic allocation. CANopen devices must provide the corresponding identifiers for the communication objects they support. The defaultID allocation table is based on … Read more
PDO stands for Process Data Object, primarily used for transmitting real-time data. PDO is divided into Receive PDO and Send PDO, where the reference objects for “Receive” and “Send” are the slave devices. The Receive PDO refers to the data received by the slave from the master, such as control words and target positions; the … Read more