Spikes in the CAN output of an RT3000 v3

Introduction

This article is written for any users that are reporting spikes in the CAN output of RT3000 v3 devices. From internal testing, we have identified two separate causes:

• the CAN cable connecting the RT3000 v3 to the CAN logger being disconnected and reconnected during use. 
• the RT3000 v3 being configured to output both RT CAN messages as well as RT-Range CAN messages. 

Disrupting the CAN connection

CAN devices in general are not designed to be disconnected and reconnected during use. When logging the CAN output of any OxTS device, we recommend that all CAN cables are connected before the device is powered up and are left undisturbed during use.

Most of our products are able to cope with the CAN connection being disconnected and reconnected. However, the behaviour we have observed with the RT3000v3 is as follows:

• After the cable is reconnected, there will be an initial flurry of spikes in many of the configured CAN messages.
• After a few seconds of activity, the spikes in most messages will stop.
• Intermittent spikes will still be observed in some of the messages until the device is power cycled. 

This issue has been fixed in a patch release of xDEV firmware. Please email support@oxts.com requesting this patch fix, mentioning that you have seen the behaviour mentioned above. 

RT and RT-Range CAN messages enabled

The RT3000 v3 combines two previously separate pieces of hardware (RT3003 v2 and RT-Range S Hunter) into one device. However, it is still configured using two separate software suites that each produce separate configuration files: 

• mobile.cfg file is produced by NAVconfig
• mobile.rng file is produced by RT-Range Suite 

The CAN output of an RT3000 v3 is controlled by both of these files. A conflict in the CAN settings in these files can lead to errors in the CAN output. To try and avoid conflict, users are instructed by the software to setup CAN in NAVconfig and only use Configure RT-Range to enable RT-Range messages. In the RT-Range software, any messages that have been enabled in NAVconfig appear in the 'Hunter' and 'Hunter Status' messages. The messages will appear as enabled but will be locked (to prevent the user introducing conflict between the two configuration files). 

A full guide for configuring CAN output on an RT3000 v3 can be found in this article. Please make sure you have followed these steps as they differ slightly from the workflow you will be used to after using our previous generation of products. 

After both NAVconfig and Configure RT-Range have been used to enable CAN output, spikes have been noticed in some of the NAVconfig CAN messages. This is a result of an issue in the mobile.rng file. If you have followed the setup steps in the article mentioned above and are experiencing this issue, please contact our support team at support@oxts.com. Please also attach the mobile.rng file from your RT3000 v3 to your email.