UDS uses the ISO-TP transport layer (ISO 15765-2). The United States standard OBD-II also uses ISO-TP. Since OBD-II uses service numbers 0x01-0x0A, UDS uses service numbers starting with 0x10, in order to avoid overlap.

ISO 15765-2, [1] or ISO-TP (Transport Layer), is an international standard for sending data packets over a CAN-Bus. The protocol allows for the transport of messages that exceed the eight byte maximum payload of CAN frames.

The data length of the ISO TP message can reach a maximum of 4095 bytes. If an ISO TP message length exceeds the data length of 8 data bytes, the UDS message must be segmented. The CAN-TP protocol works by dividing large data into smaller packets called Transport Protocol Data Units (TPDUs).

本文是对 ISO 15765-2 -2011 协议的一些解读。 需要指出该协议的最新版为2016版。 UDS网络层，又称为TP层（Transport Protocol Layer）。 其存在的目的是为了解决ISO 11898协议中定义的经典CAN数据链路层与 ISO 14229 协议中定义的应用层，彼此之间数据长度不统一的问题。 经典CAN数据链路层最大能够支持8个字节，但ISO 14229并不仅仅是为了CAN总线设计的，最大容量达到4095个字节。 比如 VIN码 是17个字节，CAN总线必然需要传递3帧才能传完VIN码，那么 …

Discover the power of the Unified Diagnostic Services (UDS) protocol in automotive vehicles. Learn how UDS enables efficient vehicle diagnostics, ECU software flashing, and more. Get insights into UDS protocol specification and testing. Follow a step-by-step tutorial to learn how to implement and utilize the UDS protocol effectively. Hi everyone!

1 day ago · Learn about a ISO 15765-2 protocol aka CAN-TP or DoCAN (Diagnostics over CAN) and how data segmentation works in vehicle Diagnostic messages.

Jan 19, 2024 · In short, UDS is a diagnostic protocol with a request-response cycle between the tester tool(client) and the ECU(server). UDS enables communication between a vehicle’s electronic control units...

In this practical tutorial, we introduce the UDS protocol basics with focus on UDS on CAN bus (UDSonCAN) and Diagnostics over CAN (DoCAN). We also introduce the ISO-TP protocol and explain the difference between UDS, OBD2, WWH-OBD and OBDonUDS.

Apr 27, 2020 · 本文是对 ISO 15765-2-2011 协议的一些解读。 需要指出该协议的最新版为2016版。 UDS网络层，又称为TP层（Transport Protocol Layer）。 其存在的目的是为了解决ISO 11898协议中定义的经典CAN 数据链路层 与ISO 14229协议中定义的应用层，彼此之间数据长度不统一的问题。 经典CAN数据链路层最大能够支持8个字节，但ISO 14229并不仅仅是为了CAN总线设计的，最大容量达到4095个字节。 比如VIN码是17个字节，CAN总线必然需要传递3帧才能 …

UDS utilizes the CAN-TP protocol to establish reliable communication between diagnostic tools and ECUs. It defines a set of diagnostic services that can be performed on ECUs, such as reading sensor data, performing actuator tests, and retrieving fault codes.