Resolve L2SS-1010 "Antenna cables"

Closes L2SS-1010

tangostationcontrol/tangostationcontrol/common/cables.py

+class CableType(object):
+    """ A cable used in LOFAR, with its properties. """
+
+    def __init__(self, name: str, length: int, delay: float, loss: dict):
+        self.name = name # for reverse lookups
+        self.length = length # metres
+        self.delay = delay # seconds
+        self.loss = loss # frequency_mhz -> dB
+
+    def speed(self):
+        """ Return the speed of the signal in this cable, in m/s. """
+
+        return self.length / self.delay
+
+    def get_loss(self, antenna_type: str, rcu_band_select: int) -> float:
+        """ Get the appropiate loss value (in dB), for the given
+            antenna type and RCU band selection. """
+
+        if antenna_type == "LBA":
+            return self.loss[50]
+        elif antenna_type == "HBA":
+            if rcu_band_select == 1:
+                return self.loss[150]
+            elif rcu_band_select == 2:
+                return self.loss[200]
+            elif rcu_band_select == 4:
+                return self.loss[250]
+            else:
+                raise ValueError(f"Unsupported RCU band selection for HBA: {rcu_band_select}")
+
+        raise ValueError(f"Unsupported antenna type: {antenna_type}")
+
+# Global list of all known cable types.
+#
+# NB: The LOFAR1 equivalents of these tables are:
+#          - MAC/Deployment/data/StaticMetaData/CableDelays/
+#          - MAC/Deployment/data/StaticMetaData/CableAttenuation.conf
+cable_types = {}
+cable_types[  "0m"] = CableType(name=  "0m", length=  0, delay=000.0000e-9, loss={50: 0.00, 150: 0.00, 200:  0.00, 250:  0.00})
+cable_types[ "50m"] = CableType(name= "50m", length= 50, delay=199.2573e-9, loss={50: 2.05, 150: 3.64, 200:  4.24, 250:  4.46})
+cable_types[ "80m"] = CableType(name= "80m", length= 80, delay=326.9640e-9, loss={50: 3.32, 150: 5.87, 200:  6.82, 250:  7.19})
+cable_types[ "85m"] = CableType(name= "85m", length= 85, delay=342.5133e-9, loss={50: 3.53, 150: 6.22, 200:  7.21, 250:  7.58})
+cable_types["115m"] = CableType(name="115m", length=115, delay=465.5254e-9, loss={50: 4.74, 150: 8.35, 200:  9.70, 250: 10.18})
+cable_types["120m"] = CableType(name="120m", length=120, delay=493.8617e-9, loss={50: 4.85, 150: 8.55, 200:  9.92, 250: 10.42}) # used on CS030
+cable_types["130m"] = CableType(name="130m", length=130, delay=530.6981e-9, loss={50: 5.40, 150: 9.52, 200: 11.06, 250: 11.61})
+