Merge branch 'opcua_demo'

lofarimaging/opc_interface.py

@@ -0,0 +1,52 @@
+import logging
+
+from opcua import ua, uamethod, Server, Client
+import numpy as np
+
+DEFAULT_URI = "http://lofar.eu"
+NUM_RCU = 96
+
+
+def download_xst(subband: int, integration_time_s: int, url: str = 'localhost', port: int = 50000):
+    """
+    Download cross correlation statistics
+
+    Args:
+        subband (int): Subband number
+        integration_time_s (int): Integration time in seconds
+        url (str): URL to connect to, defaults to 'localhost'
+        port (str): Port to connect to, defaults to 50000
+
+    Returns:
+        Tuple[datetime.datetime, np.ndarray, int]: UTC time, visibilities (shape n_ant x n_ant),
+                                                   RCU mode
+
+    Raises:
+        RuntimeError: if in mixed RCU mode
+    """
+    client = Client("opc.tcp://{}:{}/".format(url, port), timeout=1000)
+    client.connect()
+    client.load_type_definitions()
+    objects = client.get_objects_node()
+    idx = client.get_namespace_index(DEFAULT_URI)
+    obj = client.get_root_node().get_child(["0:Objects",
+                                            "{}:StationMetrics".format(idx),
+                                            "{}:RCU".format(idx)])
+
+    obstime, visibilities_opc, rcu_modes = obj.call_method("{}:record_cross".format(idx), subband, integration_time_s)
+
+    client.close_session()
+    client.close_secure_channel()
+
+    rcu_modes_on = set([mode for mode in rcu_modes if mode != '0'])
+    if len(rcu_modes_on) == 1:
+        rcu_mode = int(rcu_modes_on.pop())
+    elif len(rcu_modes_on) == 0:
+        rcu_mode = 0
+    else:
+        raise RuntimeError("Multiple nonzero RCU modes are used, that's not supported yet")
+
+    assert(len(visibilities_opc) == 2) # Real and complex part
+    visibilities = np.array(visibilities_opc)[0] + 1j * np.array(visibilities_opc[1])
+
+    return obstime, visibilities, rcu_mode

lofarimaging/singlestationutil.py

@@ -118,7 +118,7 @@ def find_caltable(field_name: str, rcu_mode: Union[str, int], caltable_dir='calt
     Find the file of a caltable.
 
     Args:
-        field_name: Name of the antenna field, e.g. 'DE602LBA'
+        field_name: Name of the antenna field, e.g. 'DE602LBA' or 'DE602'
         rcu_mode: Receiver mode for which the calibration table is requested.
         caltable_dir: Root directory under which station information is stored in
             subdirectories DE602C/etc/, RS106/etc/, ...

requirements.txt

@@ -10,3 +10,4 @@ mercantile
 owslib
 packaging
 Pillow
+opcua