diff --git a/artiq/devices/pdq2/__init__.py b/artiq/devices/pdq2/__init__.py
index 9b8b810e8..098536bfb 100644
--- a/artiq/devices/pdq2/__init__.py
+++ b/artiq/devices/pdq2/__init__.py
@@ -3,11 +3,10 @@ from artiq.language.units import *
 from artiq.coredevice import rtio
 
 
-# FIXME: check those numbers
 frame_setup = 20*ns
-trigger_duration = 100*ns
-frame_wait = 100*ns
-sample_period = 10*us
+trigger_duration = 50*ns
+frame_wait = 20*ns
+sample_period = 10*us  # FIXME: check this
 
 
 class SegmentSequenceError(Exception):
@@ -50,13 +49,19 @@ class _Frame:
         self.segment_count = 0
         self.closed = False
 
-    def append(self, name, t, u, trigger=False):
+    def append(self, t, u, trigger=False, name=None):
         if self.closed:
             raise FrameCloseError
         sn = self.segment_count
         duration = (t[-1] - t[0])*sample_period
         segment = _Segment(self, sn, duration, (t, u, trigger))
-        setattr(self, name, segment)
+        if name is None:
+            # TODO
+            raise NotImplementedError("Anonymous segments are not supported yet")
+        else:
+            if hasattr(self, name):
+                raise NameError("Segment name already exists")
+            setattr(self, name, segment)
         self.segment_count += 1
 
     def close(self):
@@ -80,6 +85,11 @@ class _Frame:
         self.pdq.trigger.on(t)
         self.pdq.trigger.off(t + time_to_cycles(trigger_duration))
 
+    @kernel
+    def advance(self):
+        # TODO
+        raise NotImplementedError
+
     @kernel
     def finish(self):
         if self.pdq.current_frame != self.fn:
diff --git a/examples/transport.py b/examples/transport.py
index 6d5f347f5..2b917cd15 100644
--- a/examples/transport.py
+++ b/examples/transport.py
@@ -22,12 +22,12 @@ class Transport(AutoContext):
         # stores duration and the fact that this segment needs to be triggered
         # both (duration and segment triggering flag) to be retrieved during
         # kernel compilation, see transport()
-        self.tf.append("to_stop",
-                       t, u, trigger=True)
+        self.tf.append(t, u, trigger=True,
+                       name="to_stop")
         # append the reverse transport (from stop to 0)
         # both durations are the same in this case
-        self.tf.append("from_stop",
-                       t[-1] - t[::-1], u[::-1], trigger=True)
+        self.tf.append(t[-1] - t[::-1], u[::-1], trigger=True,
+                       name="from_stop")
         # closes the frame with a wait line before jumping back into
         # the jump table so that frame signal can be set before the jump
         # also mark the frame as closed and prevent further append()ing