L2SS-769: Only accept valid clock settings

tangostationcontrol/tangostationcontrol/devices/sdp/sdp.py

@@ -213,6 +213,9 @@ class SDP(opcua_device):
             #raise ValueError(f"Could not determine Nyquist zone for antenna type {self.AntennaType} clock {self._clock}")
 
     def write_clock_RW(self, clock):
+        if clock not in (160*1000000, 200*1000000):
+            raise ValueError(f"Unsupported clock frequency: {clock}")
+
         # Tell all FPGAs to use this clock
         self.proxy.FPGA_pps_expected_cnt_RW = [clock] * self.N_pn