diff --git a/Software/LMSourceCode/ImageProcessing/gs_fsm.cpp b/Software/LMSourceCode/ImageProcessing/gs_fsm.cpp
index adafdc4e..25014f93 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_fsm.cpp
+++ b/Software/LMSourceCode/ImageProcessing/gs_fsm.cpp
@@ -165,6 +165,7 @@ namespace golf_sim {
         // TBD - see if we need to move this back to the initializating state
         if (!waitingForBallState.already_sent_waiting_ipc_message) {
             GsUISystem::SendIPCStatusMessage(GsIPCResultType::kWaitingForBallToAppear);
+            GsSimInterface::SendHeartbeat(false);
         }
 
         // This check will be called repeatedly by re-queuing events.
@@ -182,7 +183,8 @@ namespace golf_sim {
         }
 
         if (found) {
-
+            // Inform connected sims that the ball is on the tee.
+            GsSimInterface::SendHeartbeat(true);
             if (GolfSimOptions::GetCommandLineOptions().system_mode_ == SystemMode::kCamera1Calibrate ||
                 GolfSimOptions::GetCommandLineOptions().system_mode_ == SystemMode::kCamera2Calibrate) {
 
@@ -983,4 +985,3 @@ namespace golf_sim {
 } // GolfSim namespace
 
 #endif // #ifdef __unix__  // Ignore in Windows environment
-
diff --git a/Software/LMSourceCode/ImageProcessing/gs_gspro_results.cpp b/Software/LMSourceCode/ImageProcessing/gs_gspro_results.cpp
index 2e0ff22e..2709fb14 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_gspro_results.cpp
+++ b/Software/LMSourceCode/ImageProcessing/gs_gspro_results.cpp
@@ -76,14 +76,14 @@ namespace golf_sim {
             shot_data_options_child.put("ContainsClubData", false);
             // TBD - Consider if we want to send the next two values in a heartbeat?
             shot_data_options_child.put("LaunchMonitorIsReady", true);
-            shot_data_options_child.put("LaunchMonitorBallDetected", true);
+            shot_data_options_child.put("LaunchMonitorBallDetected", heartbeat_ball_detected_);
             shot_data_options_child.put("IsHeartBeat", false);
         }
         else {
             shot_data_options_child.put("ContainsBallData", false);
             shot_data_options_child.put("ContainsClubData", false);
             shot_data_options_child.put("LaunchMonitorIsReady", true);
-            shot_data_options_child.put("LaunchMonitorBallDetected", true);
+            shot_data_options_child.put("LaunchMonitorBallDetected", heartbeat_ball_detected_);
             shot_data_options_child.put("IsHeartBeat", true);
         }
 
diff --git a/Software/LMSourceCode/ImageProcessing/gs_results.cpp b/Software/LMSourceCode/ImageProcessing/gs_results.cpp
index 39036bdc..a94b5b3b 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_results.cpp
+++ b/Software/LMSourceCode/ImageProcessing/gs_results.cpp
@@ -32,6 +32,9 @@ namespace golf_sim {
         // but this is a reasonable default for now
         club_type_ = GolfSimClubs::GetCurrentClubType();
 
+        // Real shot data implies a ball was definitely detected.
+        heartbeat_ball_detected_ = true;
+
         // TBD - Even though this is a constructor, it might be a reasonable
         // place to calculate the Carry yardarge.
     }
diff --git a/Software/LMSourceCode/ImageProcessing/gs_results.h b/Software/LMSourceCode/ImageProcessing/gs_results.h
index 010687e8..ac2e9ee8 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_results.h
+++ b/Software/LMSourceCode/ImageProcessing/gs_results.h
@@ -52,6 +52,8 @@ namespace golf_sim {
 
         // Some systems need a keep-alive
         bool result_message_is_keepalive_ = false;
+        bool heartbeat_launch_monitor_ready_ = true;
+        bool heartbeat_ball_detected_ = false;
 
     };
 
diff --git a/Software/LMSourceCode/ImageProcessing/gs_sim_interface.cpp b/Software/LMSourceCode/ImageProcessing/gs_sim_interface.cpp
index 18cda70a..c1250bb6 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_sim_interface.cpp
+++ b/Software/LMSourceCode/ImageProcessing/gs_sim_interface.cpp
@@ -237,6 +237,26 @@ namespace golf_sim {
         shot_counter_++;
     }
 
+    void GsSimInterface::SendHeartbeat(bool ball_detected) {
+#ifdef __unix__  // Ignore in Windows environment
+        if (!sims_initialized_) {
+            return;
+        }
+
+        GsResults heartbeat;
+        heartbeat.result_message_is_keepalive_ = true;
+        heartbeat.heartbeat_ball_detected_ = ball_detected;
+        heartbeat.heartbeat_launch_monitor_ready_ = true;
+
+        for (auto interface : interfaces_) {
+            if (interface == nullptr) {
+                continue;
+            }
+            interface->SendResults(heartbeat);
+        }
+#endif
+    }
+
     bool GsSimInterface::InterfaceIsPresent() {
         // The base interface isn't a real interface, so cannot be 'present'
         return false;
diff --git a/Software/LMSourceCode/ImageProcessing/gs_sim_interface.h b/Software/LMSourceCode/ImageProcessing/gs_sim_interface.h
index 6c969578..7e12e237 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_sim_interface.h
+++ b/Software/LMSourceCode/ImageProcessing/gs_sim_interface.h
@@ -80,6 +80,10 @@ namespace golf_sim {
         // Returns true only if each of the available interfaces is armed
         static bool GetAllSystemsArmed();
 
+        // Heartbeat support for external simulators
+        static void SendHeartbeat(bool ball_detected);
+        static inline void ResetHeartbeatState() {}
+
     protected:
 
         // Typical derived-class behavior will be to convert the results into a
diff --git a/Software/LMSourceCode/ImageProcessing/gs_sim_socket_interface.cpp b/Software/LMSourceCode/ImageProcessing/gs_sim_socket_interface.cpp
index 14083607..5e960c1a 100644
--- a/Software/LMSourceCode/ImageProcessing/gs_sim_socket_interface.cpp
+++ b/Software/LMSourceCode/ImageProcessing/gs_sim_socket_interface.cpp
@@ -18,6 +18,7 @@
 #include "gs_events.h"
 #include "gs_ipc_control_msg.h"
 
+#include "gs_sim_socket_interface.h"
 #include "gs_gspro_interface.h"
 #include "gs_gspro_response.h"
 #include "gs_gspro_results.h"
@@ -95,6 +96,10 @@ namespace golf_sim {
 
         initialized_ = true;
 
+        // Connection just came up – make sure the first heartbeat reports no ball detected.
+        GsSimInterface::ResetHeartbeatState();
+        GsSimInterface::SendHeartbeat(false);
+
         // Derived classes will need to deal with any initial messaging after the socket is established.
 
         return true;