This is a bit more complicated…

pycbc/frame/frame.py

@@ -863,6 +863,12 @@ def advance(self, blocksize):
             self.null_advance(blocksize)
             return None
 
+    def attempt_advance(self, blocksize, timeout=10):
+        result = super().attempt_advance(blocksize, timeout)
+        if result is None:
+            return None
+        return self.check_valid(result)
+
 
 class iDQBuffer(object):
 

pycbc/strain/strain.py

@@ -1848,15 +1848,18 @@ def null_advance_strain(self, blocksize):
         self.taper_immediate_strain = True
 
     def advance(self, blocksize, timeout=10):
-        """Advanced buffer blocksize seconds.
+        """Advance buffer blocksize seconds.
 
         Add blocksize seconds more to the buffer, push blocksize seconds
         from the beginning.
 
         Parameters
         ----------
         blocksize: int
-            The number of seconds to attempt to read from the channel
+            The number of seconds to attempt to read from the channel.
+        timeout: {int, 10}
+            Maximum time (in seconds) to wait before declaring frame files are
+            too late and reporting unusable data.
 
         Returns
         -------
@@ -1866,7 +1869,9 @@ def advance(self, blocksize, timeout=10):
         if self.state:
             # We are using information from the state vector, so check what is
             # says about the new strain data.
-            state_advance_result = self.state.advance(blocksize)
+            state_advance_result = self.state.attempt_advance(
+                blocksize, timeout=timeout
+            )
             if not state_advance_result:
                 # Something about the state vector indicates a problem.
                 if state_advance_result is None: