SmarTak® CoT Heartbeat

Packet: CoT_SMTK_HBeat (v4.0.0)

Overview

The `CoT_SMTK_HBeat` packet is the standard Cursor on Target (CoT) message for broadcasting an asset's position and detailed status. It is a standard CoT XML "event" packet that includes a custom `` block containing the 32-bit SmarTak Status and WnA (Weapon & Ammunition) codes.

This format allows any TAK client to parse the asset's location, while SmarTak-enabled clients can parse the `` block to gain a much deeper understanding of the asset's real-time condition.

Packet Structure Breakdown

XML Element Attribute Example Value Description
<event> version '2.0' CoT schema version.
uid 'EUD-HEARTBEAT,HAMMER' Unique identifier for the event, typically combining device type and callsign.
type 'a-f-G-E-W-P' The CoT event type. This example indicates a Friendly Ground Military unit.
time '2025-11-03T20:44:19.068Z' Timestamp of when the event was generated (UTC).
start '2025-11-03T20:44:19.068Z' Timestamp of when the event starts (typically same as 'time').
stale '2025-11-03T20:44:20.068Z' Timestamp when the event should be considered stale (e.g., time + 1 sec).
how 'm-f' Indicates the source of the data (Machine-to-machine, Fused).
qos '5-f-c' Quality of Service mapping.
<point> lat '36.57428741' Latitude (WGS-84) with high precision.
lon '-87.25671387' Longitude (WGS-84) with high precision.
hae '0.0' Height Above Ellipsoid in meters.
ce '2.0' Circular Error (90% confidence) in meters.
le '2.0' Linear Error (90% confidence) in meters.
<detail> <callsign> 'HAMMER' The displayable callsign for the asset.
<smtk_status> '0x00000000' The 32-bit SmarTak Status Code. See Status Code Overview.
<smtk_wna> '0x00000000' The 32-bit SmarTak Weapon & Ammunition Code. See WnA Code Overview.

Full XML Example

<?xml version='1.0' encoding='UTF-8' standalone='yes'?>
<event version='2.0' uid='EUD-HEARTBEAT,HAMMER' type='a-f-G-E-W-P' time='2025-11-03T20:44:19.068Z' start='2025-11-03T20:44:19.068Z' stale='2025-11-03T20:44:20.068Z' how='m-f' qos='5-f-c' access='Undefined'>
    <point lat='36.57428741' lon='-87.25671387' hae='0.0' ce='2.0' le='2.0'/>
    <detail>
        <callsign>HAMMER</callsign>
        <smtk_status>0x00000000</smtk_status>
        <smtk_wna>0x00000000</smtk_wna>
    </detail>
</event>