diff --git a/central_backend/src/energy/energy_actor.rs b/central_backend/src/energy/energy_actor.rs
index 9b677cb..766eca7 100644
--- a/central_backend/src/energy/energy_actor.rs
+++ b/central_backend/src/energy/energy_actor.rs
@@ -282,11 +282,14 @@ impl Handler<SynchronizeDevice> for EnergyActor {
         self.devices.synchronise_dev_info(&msg.0, msg.1.clone())?;
         self.engine.device_state(&msg.0).record_ping();
 
-        // TODO : implement real code
+        let Some(device) = self.devices.get_single(&msg.0) else {
+            return Ok(vec![]);
+        };
+
         let mut v = vec![];
-        for i in 0..msg.1.max_relays {
+        for d in &device.relays {
             v.push(RelaySyncStatus {
-                enabled: i % 2 == 0,
+                enabled: self.engine.relay_state(d.id).is_on(),
             });
         }
         Ok(v)
diff --git a/central_backend/src/energy/engine.rs b/central_backend/src/energy/engine.rs
index d583830..54d3190 100644
--- a/central_backend/src/energy/engine.rs
+++ b/central_backend/src/energy/engine.rs
@@ -32,7 +32,7 @@ pub struct RelayState {
 }
 
 impl RelayState {
-    fn is_on(&self) -> bool {
+    pub fn is_on(&self) -> bool {
         self.on
     }