Make checking of frequency optional

camrasdevices.py

@@ -10,8 +10,9 @@ class CamrasHpibDevice(object):
 
     command_thread = None
 
-    def __init__(self, address):
+    def __init__(self, address, check_frequency=True):
         self.hpib_address = address
+        self._check_frequency = check_frequency
 
         if not CamrasHpibDevice.command_thread:
             serial_port = serial.Serial("/dev/ttyUSB0")
@@ -54,7 +55,7 @@ class CamrasHpibDevice(object):
         CamrasHpibDevice.command_thread.protocol.command("freq {:d} Hz".format(int(freq)),
                                                          address=self.hpib_address)
         new_freq = self.frequency
-        if new_freq.to(u.Hz).value != int(freq):
+        if self._check_frequency and new_freq.to(u.Hz).value != int(freq):
             raise RuntimeError("Setting frequency failed: tried to set to {}, it is now {}".format(
                 freq, new_freq))