changes

src/controllers/installationController.js

@@ -1007,10 +1007,16 @@ exports.getMasterSlaveSummary = async (req, reply) => {
 
     // Update connection status and timestamps
     const updateStatusPromises = allDevices.map(async device => {
-      const hwId = device.connected_to;
+      let checkHardwareId = device.hardwareId?.trim();
-      if (!hwId) return;
+      if (!checkHardwareId) return;
 
-      const latestData = await IotData.findOne({ hardwareId: hwId })
+      // For slave, check connection via master's hardwareId (i.e., connected_to)
+      if (device.type === 'slave') {
+        checkHardwareId = device.connected_to?.trim();
+        if (!checkHardwareId) return;
+      }
+
+      const latestData = await IotData.findOne({ hardwareId: checkHardwareId })
         .sort({ date: -1 })
         .lean();
 
@@ -1043,7 +1049,6 @@ exports.getMasterSlaveSummary = async (req, reply) => {
             device.connected_lora_time = time;
           }
         }
-        
       }
 
       updateFields.connected_status = status;