TCP Networking old
- Guy Avery (Deactivated)
- Charlotte Dakin-Norris
- Benedict Dakin-Norris (Unlicensed)
The radar acts as a TCP/IP server and therefore listens for connections once started. The server will support up to 3 concurrent client connections, therefore the first 3 clients attempting to connect will succeed, but subsequent attempts from other clients will fail. The radar supports a primary IP address and streams data over a single port, which, by default, is the IANA allocated port of TCP 6317. The IP addresses and the port are all configurable via the radar management software. Please refer to referenceĀ Vertex documentation for more information. Note that the radar TCP server maintains state on the client connections therefore message start / stop requests, such as FFT Data, are applied on a per client basis.
Typically there are 2 types of payloads;
Byte array representing a structure made up from standard C++ data types
Byte array representing a serialised Protocol Buffer message
Byte arrays that represent both of the above
For more information on Google Protocol Buffers please see reference [https://developers.google.com/protocol-buffers]. Navtech can provideĀ Protobuf message files on request.
All network data is sent in Network Order i.e. big-endian.
The Complete TCP Message Structure
The TCP Message Header
This is the first part of every message sent using this protocol. The header serves 2 purposes; the first is to provide a byte sequence for synchronisation purposes and secondly to provide information about the body of the message.
TCP Message Header Structure
Field | Type [Size] | Description |
|---|---|---|
Signature | uint8_t [16] | Unique synchronisation byte sequence |
Version | uint8_t [1] | Protocol version ā indicates the revision of the protocol messages |
Message Id | uint8_t [1] | Message type ā indicates the type of the payload |
Payload Size | uint32_t [4] | The size, in bytes, of the main body of the message |
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On this page:
TCP Message Types
Message Name | Message Id | Direction | Description |
|---|---|---|---|
Configuration | 10 | From Radar | Sends all the radar configuration properties required to configure the client software to correctly receive data |
Configuration Request | 20 | To Radar | Requests a configuration message from the radar |
Start FFT Data | 21 | To Radar | Instructs the radar to start sending FFT data until told to stop |
Stop FFT Data | 22 | To Radar | Instructs the radar to stop sending FFT data |
Start Health Msgs | 23 | To Radar | Instructs the radar to start sending regular health messages until told to stop |
Stop Health Msgs | 24 | To Radar | Instructs the radar to stop sending health messages |
Reset RF Health | 25 | To Radar | Instructs the radar to reset RF Health check system |
FFT Data | 30 | From Radar | An azimuth of raw radar data |
High Precision FFT Data | 31 | From Radar | An azimuth of high precision radar data |
Health | 40 | From Radar | Sends a radar health status message |
Contour Update | 50 | To Radar | Enables the client to update the contour map on the radar |
System Restart | 76 | To Radar | Request system reboot |
Logging Levels | 90 | To/From Radar | A list of logging levels - v2 Hardware only |
Logging Levels Request | 100 | To Radar | Request a list of logging levels - v2 Hardware only |
Start Nav Data | 120 | To Radar | Request system to start sending navigation data |
Stop Nav Data | 121 | To Radar | Request system to stop sending navigation data |
Set Nav Threshold | 122 | To Radar | Set navigation threshold |
Navigation Data | 123 | From Radar | Navigation data records |
Set Nav Range Gain and Offset | 124 | To Radar | Set navigation threshold |
CalibrateĀ Accelerometer | 125 | To Radar | Radar will store current accelerometerĀ value as flat |
StartĀ Accelerometer | 126 | To Radar | Start receivingĀ accelerometer data |
Stop Accelerometer | 127 | To Radar | Stop receivingĀ accelerometer data |
AccelerometerĀ Data | 128 | From Radar | Accelerometer Data |
Navigation Alarm Data | 143 | From Radar | SafeGuard Lite Alarms |
Navigation Area Rules | 144 | To Radar | SafeGuard Lite Area Rules |
Signature
The 16 byte signature differs very slightly from the older Navtech RMB protocol. This does enable existing software to differentiate between the two protocols if required.
The new signature is as follows:
The TCP Message Body
This payload will be variable length, the size being specified in the message header. The rest of this document describes the message types.
Configuration Message
The configuration message contains all the relevant information a client application needs to process raw data from the radar. The message provides all critical data in fixed length fields at the beginning of the message. These values are the minimum required in order to successfully configure a client. These fields can be accessed using the normal process of decoding a byte stream coming across the network. The remainder of the message is made up from a variable length Protocol Buffer message which contains additional information about the radar, such as serial numbers and service dates. Advanced customer applications would be expected to decode this message data however the information is optional.
The size of this message body is specified by the payload size field in the header. The size of the Protocol Buffer message can be calculated by subtracting the size of the fixed length fields from the payload size (i.e. Payload Size ā 22 bytes). A configuration message is always sent when a client first connects and is also sent in response to a request from the client.
Configuration Message Structure
Field | Type [Size] | Description |
|---|---|---|
Azimuth Samples | uint16_t [2] | Number of azimuth samples taken per rotation |
Bin Size / Resolution | uint16_t [2] | The range resolution per bin. In tenths of millimetres. For example 0.2997m would be 2997. |
Range In Bins | uint16_t [2] | Configured detection range, in bins |
Encoder Size | uint16_t [2] | The total number of available steps on the encoder wheel |
Rotation Speed | uint16_t [2] | The configured rotation speed for the radar. In milliHertz i.e. 2000 = 2 Hz |
Packet Rate | uint16_t [2] | Expected packet rate based on sample time and rotation speed |
Range Gain | float [4] | Gain applied to calculated ranges based on radar calibration |
Range Offset | float [4] | Fixed offset in metres, applied to calculated ranges based on radar calibration |
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Floats transmitted over the network are IEEE 754 compatible values converted to 32 bit unsigned integers in network order. They will need to be reverted to host order and then cast back to floats on the client.
In C++ the radar converts floats using the following code snippet:
union v {
float f;
uint32_t i;
};
v value;
value.f = 186.4f;
uint32_t networkData = htonl(value.i);
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Configuration Protocol Buffer Payload
FIeld | Type [Size] | Description |
|---|---|---|
Model | string | Customer friendly model name |
MAC Address | string | Networking MAC Address |
Service Date | uint32_t [4] | The date the last service was completed |
Software Version Numbers | SoftwareVersion PB Message | Collection of software version numbers |
NVRAM Contents | NVRAM PB Message | Contents of NVRAM, including radar serial number |
Range Resolution Hz | float | Resolution of each bin in Hz |
Module Serial Number | string | Processing Module Serial Number |
Auto Tune Value | int16_t [2] | Current Auto Tune Value |
Radar Unique Id | string (Guid) | Radar's Unique Id |
Data Width | int32 | 1 for 8-bit 2 for 16-bit |
Range Resolution Metres | float | Range of each bin in metres |
Radar Feature Flag | uint32 | Feature Flag bit field 1 = AutoTune, 2 = Secondary Processing Module Present |
Staring Mode | int32 | Boolean to represent staring mode enabled on radar |
On-Board MAC Address | string | On-Board Networking MAC Address - 00:00:00:00:00:00 indicates no module |
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Converting Bins to Range (m)
This information can be used to calculate the range of the radar in metres and also when receiving FFT data the range of each bin can be calculated. The following algorithm should be used:
Range = Range In Bins * Range Resolution (m) i.e. 3768 * 0.175 = 659.4 m (This radar has a total range of 659.4 m)
Range of single bin = Bin Number * Range Resolution (m) i.e. 100 * 0.175 = 17.5 m (Bin 100 is 17.5 m from the radar)
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Configuration Request Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will respond by sending a single configuration message.
Start FFT Data Request Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will respond by starting the raw radar data stream.
Stop FFT Data Request Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will respond by stopping the raw radar data stream.
Start Health Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will start sending regular health messages. By default the interval is every 5
seconds.
Stop Health Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will stop sending regular health messages.
Reset RF Health Check System
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will reset the long term health check system.
System Restart Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will reboot.
Start Navigation Data Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will start sending navigation data messages.
Stop Navigation Data Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will stop sending navigation data messages.
Set Navigation Threshold
This message is used to set the threshold for the navigation system
Set Navigation Threshold Message Structure
Field | Type [Size] | Description |
|---|---|---|
Threshold | uint16_t [2] | Threshold to use for navigation data this should be a value between 0 - 96.5 dB multiplied by 10 e.g 75.6dB is 756 |
Set Navigation Gain and Offset
This message is used to set a gain and offset that is used when by the onboard navigation system, this gain and offset are applied to the ranges found using the formula [(Target Range * Range Gain * Range Resolution) + Offset].
Set Navigation Gain and Offset Message Structure
Field | Type [Size] | Description |
|---|---|---|
Gain | uint32_t [4] | Gain multiplied by 1000000 |
Offset | uint32_t [4] | Offset multiplied by 1000000 |
FFT/High Precision Data Message
The FFT Data message contains all the necessary information to process the amplitude data for a specific azimuth. The packet consists of 4 fixed length fields and a variable length byte array of amplitude data. Each byte of amplitude data represents a range bin. The total number of reported range bins can varying per packet depending on the radar configuration. The size of this message body is specified by the payload size field in the header. The FTT Data length can be calculated by subtracting the fixed length field sizes from the overall payload size (i.e. Payload Size ā 14 bytes). FFT Data messages need to be switched on before they are sent. Once activated, FFT Data messages will be sent continuously for each sampled azimuth. FFT data will continue to be sent until the radar receives a message to stop. Clients should honour this mechanism and, where possible, send the radar a stop message before disconnecting.
FFT/High Precision Data Message Structure
Field | Type [Size] | Description |
|---|---|---|
FFT Data Offset | uint16_t [2] | The offset from the start of the payload where the FTT data starts. In this version the value will be 14 ā the FFT starts at the 15th byte |
Sweep Counter | uint16_t [2] | A counter that increments on each packet sent from the radar. The value will rollover once the maximum type size has been reached |
Azimuth | uint16_t [2] | The azimuth at which this sample of FFT data was taken |
Seconds | uint32_t [4] | Total number of seconds since the synchronised Epoch |
Split Seconds | uint32_t [4] | Part seconds. This value rolls over each second |
FFT Data | uint8_t [n] | Variable length byte array of amplitude data per range bin (If high precision then two bytes represent one bin) |
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Navigation Data Message
The Navigation Data message contains the targets found for an azimuth that were above the threshold. The packet consists of 3 fixed length fields and a variable length byte array containing target information.Ā The size of this message body is specified by the payload size field in the header.Ā The Navigation Pairs Data length can be calculated by subtracting the fixed length field sizes from the overall payload size (i.e. Payload Size ā 10 bytes).Ā Ā Navigation Data messages need to be switched on before they are sent. Once activated, NavigationĀ Data messages will be sent continuously for each sampled azimuth. NavigationĀ data will continue to be sent until the radar receives a message to stop. Clients should honour this mechanism and, where possible, send the radar a stop message before disconnecting.
Navigation Data Message Structure
Field | Type [Size] | Description |
|---|---|---|
Azimuth | uint16_t [2] | The azimuth at which this sample of data was taken |
Seconds | uint32_t [4] | Total number of seconds since the synchronised Epoch |
Split Seconds | uint32_t [4] | Part seconds. This value rolls over each second |
Navigation Data Pairs | uint8_t [n] | Pairs of ranges and powers representing targets |
Field | Type [Size] | Description |
|---|---|---|
Range | uint32_t [4] | Range in metres multiplied by 1000000 |
Power | uint16_t [2] | Power of target dB multiplied by 10 e.g 75.6dB is 756 |
Health Message
The health message includes critical health information about the radar. The payload consists of a number of health status structures, each one provides data on a specific metric, for example temperature, and includes details on the current measurement and whether the metric is within expected bounds or not. The health message payload is a Protocol Buffer serialised byte array. In order to de-serialise the message the client will need to use the Google library as described in reference [2]. Metrics may be added or changed within the content of the Protocol Buffer message. This would not result in a new protocol version for this message. Client applications consuming this message will need the latest Protobuf definition file from Navtech. These are available on request. Health messages need to be switched on before they are transmitted. Once active, health messages will be sent every 5 seconds. Messages will continue to be sent until the radar receives a message to stop. Clients should honour this mechanism and, where possible, send the radar a stop message before disconnecting.
Field | Type [Size] | Description |
|---|---|---|
Temperature | HealthInfo PB Message | Temperature health information including current operating temperature |
Rotation | HealthInfo PB Message | Rotation health information including current speed |
Packet Rate | HealthInfo PB Message | Network health information including current packet rate |
RF Health Check | HealthInfo PB Message | RF health information including current noise deviation from the norm |
Motor Current | HealthInfo PB Message | Motor health information including current draw |
Contour Update Message
The Contour Update message controls the contour mode and contour map. The contour map is held on the radar and provides a mechanism to restrict the radar detection area. The map consists of a variable range per degree (i.e. 360). When a contour map is active, data is sent out from the radar for each degree up to the range specified. If the range is zero then no data is sent for that bearing. If the contour map is disabled or in its default configuration then the full range of data is sent for every azimuth (i.e. all data). There is also a test mode which can be set on the radar ā this activates a pre-configured map which exhibits a distinctive data pattern. To disable the contour map the client should send an empty update message (just header). This will leave the contour configuration intact but tell the radar to stop using it. Alternatively the client can send a full contour map, in other words a maximum range value for each azimuth. This will have the same effect. The contour map, once active, restricts the amount of data sent over the network. The more restrictive the contour map, the less data that is sent.
Contour Update Message Structure
Log Levels Get/Set Messages
The log levels get and get messages enable a user to get the logging levels and set the logging levels of the radar software. The LoggingLevelRequest message is an empty payload message, the radar will respond with a LoggingLevel message that contains a Protocol Buffer object which is a list of Log Levels. The get log levels payload is a Protocol Buffer serialised byte array. In order to de-serialise the message the client will need to use the Google library as described in referenceĀ [https://developers.google.com/protocol-buffers].
Log Levels Structure
Log Levels Buffer Payload
Field | Type [Size] | Description |
|---|---|---|
Items | List of LogLevel PB Messages | A list of Log Level Items |
CalibrateĀ Accelerometer Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will start start the calibration process and store the values in the NVRAM.
Start Accelerometer Data Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will start sending accelerometer data messages.
Stop Accelerometer Data Message
This message contains no body / payload. The message is sent just as a header. On receiving this
message the radar will start sending accelerometer data messages.
Accelerometer Data Message
This message contains the three angles representing the tilt of the radar, ĪĀ (theta), ĪØ (psi) and Éø (phi).
Accelerometer Data Message Structure
Field | Type [Size] | Description |
|---|---|---|
ĪĀ (theta) | float [4] | Angle around axis running perpendicular to zero/north -Ā +ve Tilted Forward,Ā -ve Tilted Backward |
ĪØ (psi) | float [4] | Angle around axis running from base to stop of radome |
Éø (phi) | float [4] | Angle around axis running through radar zero/north -Ā +ve Tilted Right,Ā -ve Tilted Left |
Navigation Alarm Data
This messages contains the six alarm states of the SafeGuard Lite feature
Field | Type [Size] | Description |
|---|---|---|
Alarm States | uint8_t[6] | Each byte represents the alarm state of an areas so state[4] is the fifth alarms sate a value of 1 means alarm in area, 0 means no alarmĀ |
Navigation Area Rules
This message configures the SafeGuard Lite feature with up to six areas that can cause an alarm state if a target is detected above the area threshold inside the area
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C# Example of how to encode rules
public static class Utility
{
public static uint SwapUInt32(uint value)
{
return (uint)((SwapUInt16((ushort)((value & 0x000ffff))) << 0x10)) | (SwapUInt16((ushort)((value >> 0x10) & 0xffff)));
}
public static ushort SwapUInt16(ushort value)
{
return (ushort)(((value & 0xff) << 8) | ((value >> 8) & 0xff));
}
}
public class NavVector
{
public NavVector() { }
public NavVector(float x, float y)
{
X = x;
Y = y;
}
public float X { get; set; }
public float Y { get; set; }
public byte[] ToBytes()
{
var x = (short)(X * 10.0f);
var y = (short)(Y * 10.0f);
var data = (uint)(x << 16) | (uint)y;
return BitConverter.GetBytes(Utility.SwapUInt32(data));
}
}
public class NavArea
{
public NavArea()
{
Points = new List<NavVector>();
}
public List<NavVector> Points { get; set; }
public byte[] ToBytes()
{
var data = new List<byte>();
data.AddRange(BitConverter.GetBytes(Utility.SwapUInt16((ushort)Points.Count)));
Points.ForEach(point => { data.AddRange(point.ToBytes()); });
return data.ToArray();
}
}
public class NavAreaRule
{
public NavAreaRule()
{
Enabled = true;
InvertBreakLogic = false;
ThresholdDelta = 0.0f;
BreakAllowance = 16;
AllowanceCurveDecrement = 4;
AreaToCheck = new NavArea();
}
public byte Id { get; set; }
public bool Enabled { get; set; }
public bool InvertBreakLogic { get; set; }
public float ThresholdDelta { get; set; }
public ushort BreakAllowance { get; set; }
public ushort AllowanceCurveDecrement { get; set; }
public NavArea AreaToCheck { get; set; }
public byte[] ToBytes()
{
var ruleData = new List<byte> { Id, Enabled ? (byte)1 : (byte)0, InvertBreakLogic ? (byte)1 : (byte)0 };
ruleData.AddRange(BitConverter.GetBytes(Utility.SwapUInt16((ushort)(ThresholdDelta * 10.0f))));
ruleData.AddRange(BitConverter.GetBytes(Utility.SwapUInt16(BreakAllowance)));
ruleData.AddRange(BitConverter.GetBytes(Utility.SwapUInt16(AllowanceCurveDecrement)));
ruleData.AddRange(AreaToCheck.ToBytes());
var data = new List<byte>();
data.AddRange(BitConverter.GetBytes(Utility.SwapUInt32((uint)ruleData.Count)));
data.AddRange(ruleData);
return data.ToArray();
}
}
public class NavUpdateAreaRules
{
public NavUpdateAreaRules()
{
Rules = new List<NavAreaRule>();
}
public List<NavAreaRule> Rules { get; set; }
public byte[] ToBytes()
{
var data = new List<byte> { (byte)Rules.Count };
Rules.ForEach(rule => { data.AddRange(rule.ToBytes()); });
return data.ToArray();
}
}
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Related information
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Colossus Record and Playback Tool (Products)
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Vertex User Guide (Products)
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Colossus Network Data Protocol (Products)
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Requesting Health Messages (Industrial Automation)
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Firmware Control and Upgrade (Products)
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Changing the Configuration (Products)
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Login (Products)
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Engineer (Products)
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User - Radar Data (Products)
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User - Radar Hardware (Products)
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User - Radar Configuration (Products)
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Standard User (Products)
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Colossus File Format (Products)
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Minimal Handshaking Procedure (Products)
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Requesting Health Messages (Products)