Configure preview assemblers with new maxIdle parameter

src/calng/CalibrationManager.py

@@ -382,6 +382,16 @@ class CalibrationManager(DeviceClientBase, Device):
         accessMode=AccessMode.INITONLY,
         assignment=Assignment.MANDATORY)
 
+    maxIdle = Double(
+        displayedName='Preview source timeout',
+        description='TrainMatcher (used for preview assemblers) has an option '
+                    '(maxIdle) to automatically ignore sources which have not '
+                    'sent data in the last maxIdle seconds (if maxIdle > 0). '
+                    'Useful in case a module fails. If missing source comes '
+                    'back, it will be matched again.',
+        defaultValue=1,
+        accessMode=AccessMode.RECONFIGURABLE)
+
     webserverApi = Node(
         WebserverApiNode,
         displayedName='Webserver API',
@@ -1295,6 +1305,7 @@ class CalibrationManager(DeviceClientBase, Device):
                 for (virtual_id, device_id)
                 in correct_device_id_by_module.items()]
             config['geometryDevice'] = self.geometryDevice.value
+            config['maxIdle'] = self.maxIdle.value
 
             if not await self._instantiate_device(
                 server, class_ids['assembler'], assembler_device_id, config