Make sure attributes are polled when subscribing to them

tangostationcontrol/tangostationcontrol/common/events.py

@@ -8,6 +8,7 @@ from prometheus_client import Counter
 from tango import DeviceProxy, EventType
 
 from tangostationcontrol.common.lofar_logging import log_exceptions
+from tangostationcontrol.common.constants import DEFAULT_POLLING_PERIOD_MS
 from tangostationcontrol.metrics import AttributeMetric
 
 logger = logging.getLogger()
@@ -87,11 +88,8 @@ class EventSubscriptions:
 
         # make sure the attribute is polled, otherwise we wont receive event
         if not proxy.is_attribute_polled(attr_name):
-            logger.error(
-                f"Error, no polling_period set for attribute \
-                {proxy.name()}/{attr_name}. \
-                We will not get any events without a polling_period"
-            )
+            logger.info(f"Enabling polling for {proxy.name()}/{attr_name}.")
+            proxy.poll_attribute(attr_name, DEFAULT_POLLING_PERIOD_MS)
 
         # subscribe
         event_id = proxy.subscribe_event(