Don't query hpib twice

camrasdevices.py

@@ -23,7 +23,7 @@ class CamrasHpibDevice(HpibDevice):
         freq_str = self.query("freq?")
         if len(freq_str)==0:
             raise RuntimeError("Camras device at address {} is not responding".format(self._hpib_address))
-        return int(float(self.query("freq?"))) * u.Hz
+        return int(float(freq_str)) * u.Hz
 
     @frequency.setter
     def frequency(self, freq):