diff --git a/.travis.yml b/.travis.yml
index 5dbf2ec..0a8364d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -53,7 +53,7 @@ before_install:
 
 install:
   - export GIT_FULL_HASH=`git rev-parse HEAD`
-  - conda create -n testenv nose python=$TRAVIS_PYTHON_VERSION pytest coverage pip databroker bluesky flake8 pyFAI mongoquery codecov attrs metadatastore filestore -c conda-forge -c lightsource2-tag -c soft-matter
+  - conda create -n testenv nose python=$TRAVIS_PYTHON_VERSION pytest coverage pip databroker bluesky flake8 pyFAI mongoquery codecov attrs metadatastore filestore -c conda-forge -c lightsource2-tag -c soft-matter ophyd
   - source activate testenv
   - 'pip install https://github.com/NSLS-II/portable-mds/zipball/master#egg=portable_mds'
   - 'pip install https://github.com/NSLS-II/portable-fs/zipball/master#egg=portable_fs'
diff --git a/xpdsim/dets.py b/xpdsim/dets.py
index b243426..5844454 100644
--- a/xpdsim/dets.py
+++ b/xpdsim/dets.py
@@ -23,7 +23,7 @@
 from cycler import cycler
 from pims import ImageSequence
 from pkg_resources import resource_filename as rs_fn
-from bluesky.utils import new_uid
+from .robot import Robot
 
 DATA_DIR = rs_fn('xpdsim', 'data/')
 
@@ -61,11 +61,14 @@ class SimulatedPE1C(be.ReaderWithFileStore):
     """
 
     def __init__(self, name, read_fields, fs, shutter=None,
-                 dark_fields=None, **kwargs):
+                 dark_fields=None, Robot=None, **kwargs):
         self.images_per_set = PutGet()
         self.number_of_sets = PutGet()
         self.cam = SimulatedCam()
+        self.read_fields = read_fields
+        self.sample_num = None
         self.shutter = shutter
+        self.Robot = Robot
         self._staged = False
         super().__init__(name, read_fields, fs=fs, **kwargs)
         self.ready = True  # work around a hack in Reader
@@ -75,39 +78,25 @@ def __init__(self, name, read_fields, fs, shutter=None,
         else:
             self._dark_fields = None
 
-    def trigger(self):
-        if self.shutter and self._dark_fields and \
-                        self.shutter.read()['rad']['value'] == 0:
-            read_v = {field: {'value': func(), 'timestamp': ttime.time()}
-                      for field, func in self._dark_fields.items()
-                      if field in self.read_attrs}
-            self._result.clear()
-            for idx, (name, reading) in enumerate(read_v.items()):
-                # Save the actual reading['value'] to disk and create a record
-                # in FileStore.
-                np.save('{}_{}.npy'.format(self._path_stem, idx),
-                        reading['value'])
-                datum_id = new_uid()
-                self.fs.insert_datum(self._resource_id, datum_id,
-                                     dict(index=idx))
-                # And now change the reading in place, replacing the value with
-                # a reference to FileStore.
-                reading['value'] = datum_id
-                self._result[name] = reading
-
-            delay_time = self.exposure_time
-            if delay_time:
-                if self.loop.is_running():
-                    st = be.SimpleStatus()
-                    self.loop.call_later(delay_time, st._finished)
-                    return st
-                else:
-                    ttime.sleep(delay_time)
-
-            return be.NullStatus()
+    def trigger_read(self):
+        if self.Robot:
+            if self.Robot.get_sample_number() != \
+                  self.sample_num:
+                self.sample_num = self.Robot.get_sample_number()
+                self.read_fields.update({k: v for k, v in
+                                         self.Robot.get_fields_dict().items if k
+                                         in self.read_fields.keys()})
 
+        if self.shutter and self._dark_fields and \
+                self.shutter.read()['rad']['value'] == 0:
+            rv = {field: {'value': func(), 'timestamp': ttime.time()}
+                  for field, func in self._dark_fields.items()
+                  if field in self.read_attrs}
         else:
-            return super().trigger()
+            rv = super().trigger_read()
+        read_v = dict(rv)
+        read_v['pe1_image']['value'] = read_v['pe1_image']['value'].copy()
+        return read_v
 
 
 def build_image_cycle(path):
@@ -133,7 +122,11 @@ def build_image_cycle(path):
 chess_path = os.path.join(DATA_DIR, 'chess/')
 
 
-def det_factory(name, fs, path, shutter=None, **kwargs):
+def robot_factory(theta, sample_map=None, **kwargs):
+    return Robot(theta, sample_map=sample_map)
+
+
+def det_factory(name, fs, path, shutter=None, Robot=None, **kwargs):
     """Build a detector using real images
 
     Parameters
@@ -150,8 +143,7 @@ def det_factory(name, fs, path, shutter=None, **kwargs):
     detector: SimulatedPE1C instance
         The detector
     """
-    cycle = build_image_cycle(
-        path)
+    cycle = build_image_cycle(path)
     gen = cycle()
 
     def nexter():
@@ -160,17 +152,27 @@ def nexter():
     if shutter:
         stream_piece = next(gen)
         sample_img = stream_piece['pe1_image']
-        gen = chain((i for i in [stream_piece]), gen)  # put the piece on top
+        gen = chain((i for i in [stream_piece]), gen)
+        # put the piece on top
 
         def dark_nexter():
             return np.zeros(sample_img.shape)
 
-        return SimulatedPE1C(name,
-                             {'pe1_image': lambda: nexter()}, fs=fs,
-                             shutter=shutter,
-                             dark_fields={'pe1_image': lambda: dark_nexter()},
+        if Robot is None:
+            return SimulatedPE1C(name, {'pe1_image': lambda: nexter()},
+                                 fs=fs, shutter=shutter,
+                                 dark_fields={'pe1_image': lambda:
+                                              dark_nexter()}, **kwargs)
+        else:
+            return SimulatedPE1C(name, {'pe1_image': lambda: nexter()},
+                                 fs=fs, shutter=shutter,
+                                 dark_fields={'pe1_image': lambda:
+                                              dark_nexter()},
+                                 Robot=Robot, **kwargs)
+
+    if Robot is None:
+        return SimulatedPE1C(name, {'pe1_image': lambda: nexter()}, fs=fs,
                              **kwargs)
-
-    return SimulatedPE1C(name,
-                         {'pe1_image': lambda: nexter()}, fs=fs,
-                         **kwargs)
+    else:
+        return SimulatedPE1C(name, {'pe1_image': lambda: nexter()}, fs=fs,
+                             Robot=Robot, **kwargs)
diff --git a/xpdsim/robot.py b/xpdsim/robot.py
new file mode 100644
index 0000000..1334f8e
--- /dev/null
+++ b/xpdsim/robot.py
@@ -0,0 +1,102 @@
+# Detector will get the sample information from the robot via a mediator to
+# determine which image to display.
+import asyncio
+from ophyd import Device, EpicsSignal, EpicsSignalRO
+from ophyd import Component as Cpt
+from ophyd import Signal
+from ophyd.utils import set_and_wait
+from bluesky import Msg
+from bluesky.plans import subs_wrapper, count, list_scan, single_gen
+from bluesky.callbacks import LiveTable
+import time as ttime
+
+
+class Robot(Device):
+    sample_number = Cpt(Signal, value=0)
+    load_cmd = Cpt(Signal, value=0)
+    unload_cmd = Cpt(Signal, value=0)
+    execute_cmd = Cpt(Signal, value=0)
+    status = Cpt(Signal, value=0)
+    current_sample_number = Cpt(Signal, value=0)
+
+    # Map sample types to load position and measurement position
+    TH_POS = {'capillary': {'load': None, 'measure': None},
+              'plate': {'load': 0, 'measure': 90},
+              None: {'load': None, 'measure': None}}
+
+    def __init__(self, theta, *args, sample_map=None, **kwargs):
+        self.theta = theta  # theta is a motor
+        self.sample_map = sample_map
+        # sample_map = {sample #: {'pe1_image: nexter}
+        self._current_sample_geometry = None
+        super().__init__("", *args, **kwargs)
+
+    def get_fields_dict(self):
+        n = self.get_sample_number()
+        return self.sample_map[n]
+
+    def get_sample_number(self):
+        return self.sample_number
+
+    def _poll_until_idle(self):
+        ttime.sleep(3)  # gives robot plenty of time to start
+        while self.status.get() != 'Idle':
+            ttime.sleep(.1)
+
+    def _poll_until_sample_cleared(self):
+        while self.current_sample_number.get() != 0:
+            ttime.sleep(.1)
+
+    def load_sample(self, sample_number, sample_geometry=None):
+        # If no sample is loaded, current_sample_number = 0
+        # is reported by the robot
+        if self.current_sample_number.get() != 0:
+            raise RuntimeError("Sample %d is already loaded."
+                               % self.current_sample_number.get())
+
+        # Rotate theta into loading position if necessary
+        load_pos = self.TH_POS[sample_geometry]['load']
+        if load_pos is not None:
+            print('Moving theta to load position')
+            self.theta.move(load_pos, wait=True)
+
+        # Loading the sample is a three-step procedure:
+        # Set sample_number; issue load_cmd; issue execute_cmd.
+        set_and_wait(self.sample_number, sample_number)
+        set_and_wait(self.load_cmd, 1)
+        # set_and_wait is an ophyd.utils import
+        self.execute_cmd.put(1)
+        print('Loading...')
+        self._poll_until_idle()
+
+        # Rotate theta into measurement position if necessary
+        measure_pos = self.TH_POS[sample_geometry]['measure']
+        if measure_pos is not None:
+            print('Moving theta to measure position')
+            self.theta.move(measure_pos, wait=True)
+
+        # Stash the current sample geomtery for reference when we unload
+        self._current_sample_geometry = sample_geometry
+
+    def unload_sample(self):
+        if self.current_sample_number.get() == 0:
+            # there is nothing to do
+            return
+
+        # Rotate theta into loading position if necessary (e.g. flat plate
+        # model)
+        load_pos = self.TH_POS[self._current_sample_geomgery]['load']
+        if load_pos is not None:
+            print('Moving theta to unload position')
+            self.theta.move(load_pos, wait=True)
+
+        set_and_wait(self.unload_cmd, 1)
+        self.execute_cmd.put(1)
+        print('Unloading...')
+        self._poll_until_idle()
+        self._poll_until_sample_cleared()
+        self._current_sample_geometry = None
+
+    def stop(self):
+        self.theta.stop()
+        super().stop()
diff --git a/xpdsim/tests/test_dets.py b/xpdsim/tests/test_dets.py
index d7c4f27..72221cd 100644
--- a/xpdsim/tests/test_dets.py
+++ b/xpdsim/tests/test_dets.py
@@ -41,12 +41,13 @@ def test_dets_shutter(db, tmp_dir, name, fp):
     for n, d in db.restream(db[-1], fill=True):
         if n == 'event':
             assert_array_equal(d['data']['pe1_image'],
-                               np.zeros(next(cg)['pe1_image'].shape))
+                               np.zeros(d['data']['pe1_image'].shape))
     assert uid is not None
 
     # With the shutter up
     RE(abs_set(shctl1, 1, wait=True))
     uid = RE(scan)
+    next(cg)
     for n, d in db.restream(db[-1], fill=True):
         if n == 'event':
             assert_array_equal(d['data']['pe1_image'], next(cg)['pe1_image'])
diff --git a/xpdsim/tests/test_robot.py b/xpdsim/tests/test_robot.py
new file mode 100644
index 0000000..a788e09
--- /dev/null
+++ b/xpdsim/tests/test_robot.py
@@ -0,0 +1,35 @@
+import bluesky.examples as be
+from bluesky.plans import Count
+from bluesky.tests.utils import setup_test_run_engine
+from numpy.testing import assert_array_equal
+from ..dets import robot_factory, nsls_ii_path, build_image_cycle, \
+    chess_path, det_factory
+
+
+test_params = [('nslsii', nsls_ii_path), ('chess', chess_path)]
+
+
+# @pytest.mark.parametrize(('name', 'fp'), test_params)
+def test_robot(db, tmp_dir):
+    th = be.Mover('theta', {'theta': lambda x: x}, {'x': 0})
+    sm = {}
+    for i, (name, path) in enumerate(test_params):
+        cycle = build_image_cycle(path)
+        gen = cycle()
+
+        def nexter():
+            return next(gen)['pe1_image']
+        sm[i] = {'pe1_image': lambda: nexter()}
+        r = robot_factory(th, sample_map=sm)
+    det = det_factory(name, db.fs, path, save_path=tmp_dir, Robot=r)
+    RE = setup_test_run_engine()
+    RE.subscribe('all', db.mds.insert)
+    scan = Count([det], )
+    uid = RE(scan)
+    db.fs.register_handler('RWFS_NPY', be.ReaderWithFSHandler)
+    cycle2 = build_image_cycle()
+    cg = cycle2()
+    for n, d in db.restream(db[-1], fill=True):
+        if n == 'event':
+            assert_array_equal(d['data']['pe1_image'], next(cg)['pe1_image'])
+    assert uid is not None