Struggling and approaching the essence of RXSWIN

Continuing from the last time, I'm trying to translate the article about RXSWIN, which is the top 2 most accessed article on this blog, into English so that overseas readers can access it and connect it to two-way communication.

The original Japanese article is here.

No information on RXSWIN

As of today, looking at the access destinations of this blog, the following are the most common, accounting for about 40%.

It's a selfish guess, but I think it's probably because people who searched for RXSWIN are visiting. It seems that there is not much information about RXSWIN. I also learned about RXSWIN for the first time when I wrote the above, but since I found some English materials again this time, I would like to dig deeper into RXSWIN. I'm not so confident that the source is reliable information, but I will start the story from now on on the assumption that there is no one who likes to describe maniac things such as RXSWIN. If you search for "Report of Japanese Test Phase <Software Update>" on the Internet, you can find similar materials.

What is RXSWIN again?

Let's take a look at pwc's site, which was referred to in the above article.

Along with the requirements for secure software updates, the use of an identifier called RXSWIN for configuration management is also a key point in the requirements of this regulatory standard.

RXSWIN (Rx Software Identification Number) is an identifier for managing the software version of the related system for each Regulation No. in the regulations (UN Regulations) regarding the structure and equipment of automobiles.

Let's use this RXSWIN to safely update the software of the ECU installed in the vehicle, which is required by WP29 SU Regulations (UN-R156), and to enable configuration management for each UN regulation. In the previous article, I read the contents of pwc and showed a concrete example, so if you can not get an image, please refer to that as well. It is the same as the bill of materials (BOM).

This time, I would like to understand the definition of RXSWIN rather than an image. I will refer to the English materials mentioned above,

• RXSWIN consists of up to 50 letters and numbers. (Each manufacturer can define their own numbering rules.)

• RXSWIN must be able to read through an electronic interface or a standard interface (OBD port).

• The software versions used by the components and their association with RXSWIN must be recorded.
• You must submit the association information with RXSWIN to the authorities.
• RXSWIN must be managed even after vehicle registration.

Although I omitted it apart, the above definition was described. You can define a numbering rule for each company with a maximum of 50 characters. It is true that BOM is one of the most important confidential information of each company, so it would be unrealistic to standardize the definition of RXSWIN related to it.

Nowadays, what is OBD?

The second definition mentions reading through the OBD port, but let's take a look at what this OBD port is. Most of you may know that you can reach such a blog, but please forgive me because there are some people like me who can hardly mess with the car.

Now it has been upgraded to OBD2 (On Board Diagnosis second generation), and it is installed on all new cars including imported cars sold after September 2010 as a self-diagnosis function that the car itself detects abnormalities of the car. OBD2 collects not only abnormal data but also various information from sensors attached to the car body. Data such as vehicle speed, GPS, and fuel consumption are also available. The connection destinations for reading these are called OBD ports, OBD2 connectors, etc., and in reality, the ones shown below are under the steering wheel of the driver's seat or near the accelerator pedal. I will also check it with my car.

https://carcareplus.jp/article/2018/01/01/3372.html

Of course, I haven't done it myself, but when I took it to the dealer for inspection, etc., it probably connected to the OBD2 connector as shown in the figure below and checked for any abnormalities.

https://carcareplus.jp/article/2018/01/01/3372.html

Association of UN rules with ECU software

Let's move on to the third and subsequent definitions, which are the core of RXSWIN. As a result of reading the English material referred to this time, the UN rule is a large numbering unit for RXSWIN, but considering the relationship with ECU software, my understanding is as shown in the figure below.

* SysID appears here, but in the reference materials, this was positioned as the control number on the design side. To the last, RXSWIN is numbered within the certification department that communicates with the authorities, and it seems that there is a premise that it is managed by a different ID at the time of design. I'm personally convinced that it is, but be careful.

For example, there is a vehicle XXX-YYY, and as ECU software corresponding to UN13-H (M1 classification*1 brake), ABS (Anti-lock Braking System) and EPS (Electric Power Steering: electric power) Steering) is installed, and each software version is managed. This is an example of assigning this association as SysID "BR-Sys02" and RXSWIN "XXX-YYY-UN13H-Sys02". In the case of UN39, ABS is related, and in the case of UN79, EPS is related, and the corresponding RX SWIN is numbered.

It's already self-evident, but what you can see from this figure is that any updates to the ABS software will affect UN13-H and UN39, so you'll need to renumber the two RXSWINs and interact with the authorities. Since there is no effect on UN79, it is not necessary to renumber "XXX-YYY-UN79-Sys01".

When a design change occurs in an ECU, it will eventually be necessary to renumber the corresponding RX SWIN and notify the authorities. In order for this process to proceed smoothly, we can see that the following three points need to be correctly recorded and managed as shown in the above figure.

• A version of each ECU software installed in each model of each vehicle
• UN rules
• RXSWIN (also SysID, which is the numbering source)

Will the design change process change?

In addition, it turns out that accumulating and managing associations in a database is not enough. In order for a series of processes from design change drafting to RXSWIN numbering/notification to be performed properly, a workflow-like mechanism is also required.

Using the design change ID as a key, the target ECU software, its version, and the affected UN rules will be clarified together with the numbered RXSWIN, and information will be linked to the certification department that communicates with the authorities. Until now, the design change process was until the changes in the E-BOM were reflected in the M-BOM. However, RXSWIN numbering and even notification to the authorities are added to the scope, complicating the design change process and making it difficult to manage.

No, how do each car company respond? Whether it is to modify the BOM so that RXSWIN can be numbered, or to build an external management system without touching the BOM, it seems necessary to develop a difficult system. Since it is the world of each company, we cannot expect a package system that can be easily attached externally. I would like to think carefully about what kind of proposals I should make to my customers.

*1:I didn't know at all, but it seems that passenger cars in Japan are called M1 in Europe, and in UN13-H, the brakes installed in M1 vehicles are targeted.