# Altos V4 and RCU+RF6 User Guide **URL:** \ **Category:** Guides\ **Tags:** demo, support, guide\ **Created:** [May 7, 2026, 9:57am UTC](https://forum.altosradar.com/t/altos-v4-and-rcu-rf6-user-guide/72 "2026-05-07T09:57:21Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![mingkangli](https://avatars.discourse-cdn.com/v4/letter/m/b77776/32.png) [@mingkangli](https://forum.altosradar.com/u/mingkangli)\ **Post date:** [May 7, 2026, 9:57am UTC](https://forum.altosradar.com/t/altos-v4-and-rcu-rf6-user-guide/72/1 "2026-05-07T09:57:21Z")
# Intro [V4] Specification (preliminary): [EN](https://nx35326.your-storageshare.de/s/RLZKS6ZmWxMaCZC) [RCU+RF6] Specification (preliminary): [EN](https://nx35326.your-storageshare.de/s/p5pti94swySWwxn) Demo Videos: [homepage](https://www.altosradar.com/product.html), [YouTube](https://www.youtube.com/@AltosRadar), [bilibili](https://space.bilibili.com/3493282053097802) Linkedin: [Link](https://www.linkedin.com/company/altos-radar) Papers & Datasets: [Link](https://forum.altosradar.com/t/papers-dataset-with-altos-radar/62) # Setup ## [V4] Hardware Setup Assemble the cable harness following this guide: [Link to document](https://nx35326.your-storageshare.de/s/tr32SXD34D6qFbm) Input Power Requirement: 9-36 V, \>25 W Power Connector: 5.5 × 2.5 mm barrel jack (default) Ethernet Connector: 100BASE‑T1 or RJ45 (via adapter) Further details regarding the CAD file and cable harness are provided in the following sections. > [@](#): > > ### ⚠ Warning > > Please take care when plugging in the connector: [Link to document](https://nx35326.your-storageshare.de/s/XKdFXbF8n8xBxrm) > [@](#): > > ### ⚠ Warning > > Please note that not all USB-A/USB‑C to Ethernet adapters are compatible with the radar sample. Faulty adapters have been known to cause operational issues. Please refer to [Known Good Ethernet to USB-C/USB-A adapters](https://forum.altosradar.com/t/known-good-ethernet-to-usb-c-usb-a-adapters-for-altos-v1-radar/21) Connect the power source to the device. The board will then begin its power‑on sequence, which typically takes approximately 10–20 seconds to complete. > [@](#): > > ### ⚠ Warning > > Once the sample has powered on and entered normal operation, it will warm up rapidly. Please exercise caution when handling the sample during or immediately after operation. ## [RCU+RF6] Hardware Setup Connect the cable harness following this guide: [Link to document](https://nx35326.your-storageshare.de/s/BQ8trcQoKYAfsNb) Input Power Requirement: 9-36 V, \>25 W (Considering power loss during transmission, a power supply rated above **12V/3A** is recommended.) > [@](#): > > ### ⚠ Warning > > The radars only work as pairs: > • radar0+radar1 > • radar2+radar3 > • radar0+radar1+radar2+radar3 > [@](#): > > ### ⚠ Warning > > The RF6 with GMSL2 does not support hot-plugging. Please connect the RF6 to the RCU first, and then power on the RCU. > [@](#): > > ### ⚠ Warning > > An RCU with an SN label is only compatible with RF6 units that also carry an SN label, and will not work with unlabeled RF6 units. ## [RCU+RF6] GMSL2 Link Margin Test GMSL2 cable specs need to be complied with. If unsure, please run the GMSL2 link margin test as described below. 1. Connect all cable harnesses between the RCU and the 4 RF6 units. 2. Open a terminal and execute: `curl http://192.168.3.10:3000/forward_link_margin` This will take a few minutes and will output 4 values representing the forward link margins for the 4 GMSL2 connections. The unit is mV. All values must be greater than **150**. 3. Power cycle the RCU, then repeat step 2 using the following command: `curl http://192.168.3.10:3000/reverse_link_margin` The resulting values must be greater than **90**. ## Software Setup SW Requirements for ROS driver: ROS 1 Noetic + Ubuntu 20.04 or ROS 2 Jazzy + Ubuntu 24.04. Default IP Address: 192.168.3.10 Further details regarding the software interface can be found in the following sections. Open Settings in Linux and navigate to the Network tab. ![Set PC](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/e6d283621f4cf303c8c649f67c3e67bc361ee797.png) If your machine has multiple network interfaces, you will see several devices listed—similar to the screenshot above. Locate the device that corresponds to the Ethernet connection used with the radar sample. In the example shown, a USB‑C adapter was used, so the device appears as “USB Ethernet.” Click the gear icon next to the appropriate network device, then switch to the IPv4 tab. Under IPv4 Method, select Manual. In the Addresses section, add a new entry with the following values: ```auto Address: 192.168.3.1 Netmask: 255.255.255.0 ``` Leave the Gateway field empty. The window should now appear like this. Click Apply to save the changes. ![Set PC IP](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/c7548f144a066508eab657d5710397755b733f42.png) ## System Status - Radar Status: “active” means the radar is working normally. Other statuses (e.g., “activating”, “deactivating”, or “failed”) mean the radar is not working. - Ethernet Status: The SQI (Signal Quality Indication) value ranges from 0 to 7. Only a value of 4 or higher is good. - Firmware Version - Serial Number If any parameter is not shown, please update the firmware to the latest version: [Firmware Update](https://forum.altosradar.com/t/altos-v4-and-rcu-rf6-user-guide/72#p-87-firmware-update-20) ![System Status](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/c72e723563c352df31f789581bbbb4ebf8723a7c.png) ## Changing IP address With radar powered on and connected to a PC. In a web browser, type in address [http://192.168.3.10:3000](http://192.168.3.10:3000) Then click on “Network configuration” Then type the address and click “Apply” > [@](#): > > ### ⚠ Warning > > Please ensure that the `/24` subnet notation is retained in the radar’s IP address configuration, i.e., the address should be formatted as `xxx.xxx.xxx.xxx/24`. > > The radar and the gateway (data receiver) must be configured with IP addresses that belong to the same subnet, but each must have a unique address within that subnet. > For multicast, the IP address of **gateway** must be entered in the yaml file of ROS driver after **localIp** (e.g. in [altosParserRcu.yaml](https://github.com/Altos-Radar/altosRadarParser/blob/main/src/altosparser/param/altosParserRcu.yaml#L19)) ![change IP](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/72cb79124cd8b5dc94905fabcd8f7fbbed38626c.jpeg) ## Changing Multi/Unicast Destination Address The multi/unicast destination address can be configured in the “Installation Configuration” section. > [@](#): > > For multicast: > The destination **IP address** must be entered in the yaml file after **groupIp** > [@](#): > > For unicast: > The destination **IP address** must be a unique address within the same subnet as the radar. The data receiver (e.g. the PC) must be configured to use this IP address. > The destination **IP address** must be entered in the yaml file after **localIp** For both multicast and unicast, the destination **port** must be entered in the yaml file after **destPort** ## Selecting Operating Mode The operating mode can be selected at the drop down manual of “Profile” under “Installation configuration”. The operating mode can be changed in real time with the radar stopping for seconds. The mode with \_1 is recommended, as it offers better range resolution than the mode with \_0. ![Operating Mode](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/d858c7d8e7d06eb85b87f69283cbafb5bc1b9bd9.png) ## Config with Command Line In the web GUI, clicking “CURL” besides the button “APPLY” can generate the command line. Change the values in the command line by need. # Software Interface The sensor sends out point clouds as UDP packet via Ethernet. [RCU][V4] C++ Header for UDP: [altos-pc-v2.h](https://github.com/Altos-Radar/altosRadarParser/blob/main/src/altosparser/src/altos-pc-v2.h "altos-pc-v2.h") [RCU][V4] Interface Control Document: [Link to document](https://nx35326.your-storageshare.de/s/8JcEr8tNKTjdw7Q) ## ROS Driver [RCU][V4] ROS1 Noetic: [Link to repo](https://github.com/Altos-Radar/altosRadarParser) [RCU][V4] ROS2 Jazzy: [Link to repo](https://github.com/Altos-Radar/altosRadarParserRos2) UDP data is converted into standard ros msg format: sensor\_msgs/PointCloud2. The data fields of pcl::PointXYZHSV: - x, y, z: coordinates in [m]. The origin point is the center of radar radome. The coordinate system is right-handed: x-forward, y-left and z-up. - h: measured relative doppler velocity in [m/s]. - s: estimated RCS in [dBsm], calculated from SNR, distance, and angle. RCS ([Radar Cross Section](https://en.wikipedia.org/wiki/Radar_cross_section)) indicates the reflection strength of an object and can be used as an indicator of detection confidence or reliability. The value is logarithmic [dBsm]. If needed, you can modify the corresponding code to output SNR instead. - v: moving status, [-1,0,1] = [moving towards, standing, moving away]. We do not use any external data, e.g. from IMU, but only the radar point cloud to estimate the ego velocity and to determine the point moving status. > [@](#): > > ### ⚠ Warning > > The coordinate system of point clouds in the origin UDP data is: x-forward, y-left and z- **down**. > The elevation is flipped in the ROS driver with **FLIPELELVATION** to make the coordinate system right-handed. ## Distinguish Point Clouds from Each RF6 and V4 The ROS topic names for the point clouds are defined in the YAML configuration file. The configured name is used as both the ROS topic name and the frame ID. [V4] ROS1 Noetic: [altosParserV4.yaml](https://github.com/Altos-Radar/altosRadarParser/blob/main/src/altosparser/param/altosParserV4.yaml) ROS2 Jazzy: [altosParserV4.yaml](https://github.com/Altos-Radar/altosRadarParserRos2/blob/main/src/altosparser/param/altosParserV4.yaml) → `radar0: topicName: 'radarV4'` [RF6] ROS1 Noetic: [altosParserRcu.yaml](https://github.com/Altos-Radar/altosRadarParser/blob/main/src/altosparser/param/altosParserRcu.yaml) ROS2 Jazzy: [altosParserRcu.yaml](https://github.com/Altos-Radar/altosRadarParserRos2/blob/main/src/altosparser/param/altosParserRcu.yaml) → RCU: radar0-3 = port from left to right `radar0: topicName: 'radarFL'` `radar1: topicName: 'radarFR'` `radar2: topicName: 'radarRL'` `radar3: topicName: 'radarRR'` ## Wireshark Lua Dissector [altos.lua](https://github.com/Altos-Radar/altosRadarParser/blob/main/altos.lua) Enable Wireshark → Edit → Preferences → Protocols → ALTOS → Decode points # PTP and Timestamps PTP manual: [Link to document](https://nx35326.your-storageshare.de/s/cA8Hm9yoX5RY4JN) The example provided in the manual matches the default settings in the configuration page. Please do not change the default settings. ## ROS Timestamps The actual capturing / measurement time of each frame is sent out in the UDP packets (see Interface Control Document). The default header.stamp uses ros::Time::now() in the PC, since it is easy for visualization in rviz without correct PTP time, see _output.header.stamp = ros::Time::now()._ After setting up PTP, you can decode the timestamp from UDP packets and save it into header.stamp. The timestamp is generated at the midpoint of the modulation. > [@](#): > > ### ⚠ Warning > > Timestamps on point clouds are in [UTC](https://en.wikipedia.org/wiki/Coordinated_Universal_Time). The sample can be configured to use TAI while using PTP by setting utc\_offset in the PTP configuration to 0. utc\_offset should be 37 otherwise. ## FPS Limit The FPS limit is configurable in the “Installation configuration” section. The maximum supported FPS is 15Hz on both V4 and RCU. ## Second Offset-Based Triggering Triggering with a configurable offset from the UTC second can be enabled and adjusted in the “Installation configuration” section. To use the second offset, ⚠ the FPS limit must be activated and set to an integer value; otherwise, some triggers may be skipped. Each trigger event generates a number of frames equal to the configured FPS limit. The trigger time—or equivalently, the timestamp of the first frame—is aligned with the integer second boundary of the reference time, shifted by the specified second offset. Trigger timing typically exhibits jitter in the range of tens of microseconds (μs). [V4] ![Sync Mode](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/193ef922b941f05c11a8edf882b3526e5e348e18.png) [RCU] When using four RF4 units, set the PPS offsets as follows to avoid interference between the radars: Port 1: 0 s, Port 2: 0.165 s, Port 3: 0.033 s, Port 4: 0.0495 s (see the picture below). ![PPS Offset](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/b5e1f3dd928cd67d7a9672170bd6a2030c14f681.png) # Firmware Update > [@](#): > > ### ⚠ Warning > > Please provide the firmware version shown on the configuration page, and ask your contact at Altos Radar for the link to the newest firmware. With radar powered on and connected to a PC. In a web browser, type in address [http://192.168.3.10:8080](http://192.168.3.10:8080) Then drag the \*.SWU files that Altos Radar provided to the software update box on the webpage. ![sw update](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/aa3ba836b1f14c7ba46b2d88d44809994b5a82f7.jpeg) After a minute or so, if it succeeded there will be a message and the radar will restart. Alternatively, once the message “SWUPDATE successful !” appeared, it’s OK to power cycle the radar manually. ![updated succeed](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/f7ecabcc00ca89a46ce2631b16406b65c9df3970.jpeg) > [@](#): > > ### ⚠ Warning > > There is an issue after firmware update that the webpage could not be accessed with the current browser. > Please hard/force refresh the webpage, e.g. Ctrl + Shift + R in Firefox. > [@](#): > > ### ⚠ Warning > > SW update won’t change the settings in the configuration page, things like IP address, mode selections, etc. will stay the same. ## Update by Command Line `curl --form file='@altos-xx-rootfs-xxxx.swu' http://192.168.3.10:8080/upload` Replace the swu file name and IP address if changed. Wait a few minutes after the curl command completes and the radar will automatically reboot ## Check Radar Info By command line: `curl http://192.168.3.10:3000/status` By web browser: `http://192.168.3.10:3000/status` Example return: ```auto { "machine_name": "Altos V4", "firmware_ver": "e33143eb", "serial_num": "V4-260804-0060", "rf_serial_num": [], "current_partition": "a", "profiles": [ "150m_0", "150m_1", "320m_0", "320m_1", "620m_0", "620m_1" ], "calibrations": [ "150m_0", "150m_1", "320m_0", "320m_1", "620m_0", "620m_1" ] } ``` # CAD File [V4] [Link to step file](https://nx35326.your-storageshare.de/s/3Ani25CzZGNGTPg) [RF6] [Link to step file](https://nx35326.your-storageshare.de/s/8ZzYESsGsjjsx2c) [RCU] [Link to step file](https://nx35326.your-storageshare.de/s/qnbpLNTAmExHJxt) # [V4] Cable Harness V4 uses a 2+6 pin radar connector, including DC voltage supply and 100 base-T1. **Connector Pin Assignment:** [Link to document](https://nx35326.your-storageshare.de/s/8sewmb92iatTtMM) ![Pinout](https://canada1.discourse-cdn.com/flex003/uploads/altosradar/original/1X/541dad36bc1e45a20e804576836996c3b261b515.png) # [RCU] Cable Harness [Link to document](https://nx35326.your-storageshare.de/s/tr32SXD34D6qFbm) **Connector on RCU:** FAKRA: TE 2291392-1 Ethernet: TE 2304372-1 Power: Molex Mini-Fit Jr. 4-pin (2×2), 4.2 mm pitch, Molex 46999-0014 (Pinout: Top-PWR, Bottom-GND) **Connector on RF6:** Amphenol FKMZ-SPCM12-NT5GP-50 (Fakra Male) Coaxial Cable: FAKRA female-to-female, Code A/Z Ethernet Cable: TE MATEnet, Code A/Z Power Cable: 18 AWG and above # Support If you require further assistance, please contact our team directly at [support@altosradar.com](mailto:support@altosradar.com). We will respond as soon as possible.