diff --git a/awg_data.py b/awg_data.py
index 41aab75..2e42b38 100644
--- a/awg_data.py
+++ b/awg_data.py
@@ -2,15 +2,19 @@
 import numpy as np
 
 class RunsFiles:
-    def __init__(self, uut, files):
+    def __init__(self, uut, files, run_forever=False):
         self.uut = uut
         self.files = files
+        self.run_forever = run_forever
         
     def load(self):
-        for f in self.files:
-            with open(f, mode='r') as fp:
-                self.uut.load_awg(fp.read())
-            yield f        
+        for ii in range(99999 if self.run_forever else 1):
+            for f in self.files:
+                with open(f, mode='r') as fp:
+                    self.uut.load_awg(fp.read())
+                yield f 
+            
+    
 
 
 class RainbowGen:
@@ -30,25 +34,26 @@ def sinc(self, ch):
         nsam = self.nsam
         nchan = self.nchan
         NCYCLES = self.NCYCLES
-        xoff = ch*nsam/NCYCLES/10
+        xoff = ch*100
         xx = np.array(range(-nsam/2-xoff,nsam/2-xoff))*NCYCLES*2*np.pi/nsam
         return [ np.sin(x)/x if x != 0 else 1 for x in xx ]
     
-    def __init__(self, uut, nchan, nsam):
+    def __init__(self, uut, nchan, nsam, run_forever=False):
         self.uut = uut
         self.nchan = nchan
-        self.nsam = nsam        
+        self.nsam = nsam
+        self.run_forever = run_forever
         self.sw = self.sin()        
         self.aw = np.zeros((nsam,nchan))
         for ch in range(nchan):
             self.aw[:,ch] = self.rainbow(ch)
 
-    def load(self):        
-        #for ch in range(self.nchan):
-        for ch in range(8):             # convenient to plot 8
-            aw1 = np.copy(self.aw)
-            aw1[:,ch] = np.add(np.multiply(self.sinc(ch),5),2)
-            print("loading array ", aw1.shape)
-            self.uut.load_awg((aw1*(2**15-1)/10).astype(np.int16))           
-            print("loaded array ", aw1.shape)
-            yield ch
+    def load(self):
+        for ii in range(99999 if self.run_forever else 1):
+            for ch in range(self.nchan):        
+                aw1 = np.copy(self.aw)
+                aw1[:,ch] = np.add(np.multiply(self.sinc(ch),5),2)
+                print("loading array ", aw1.shape)
+                self.uut.load_awg((aw1*(2**15-1)/10).astype(np.int16))           
+                print("loaded array ", aw1.shape)
+                yield ch
diff --git a/hil_plot.py b/hil_plot.py
new file mode 100755
index 0000000..0d92579
--- /dev/null
+++ b/hil_plot.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+# Harware In Loop : load AO data,run a shot, get AI data, repeat.
+# upload to AWG and optionally run a capture.
+# data for upload is either File (host-local data file) or Rainbow, a test pattern.
+# assumes that clocking has been pre-assigned.
+
+import sys
+import acq400_hapi
+import awg_data
+import argparse
+import numpy as np
+import matplotlib.pyplot as plt
+
+def store_file(it, rdata, nchan, nsam):
+    fn = 'DATA/ai%04d.dat' % (it)
+    print("store_file {}".format(fn))
+    
+    with open(fn, 'w') as f:        
+        f.write(rdata)
+
+def plot(it, rdata, nchan, nsam):
+    raw = np.fromstring(rdata, dtype=np.int16)
+    chx = np.reshape(raw, (nsam, nchan))    
+    for ch in range(0,nchan):
+        plt.plot(chx[:,ch])
+        
+    plt.show()
+    plt.pause(0.0001)
+    
+def run_shots(args):
+    uut = acq400_hapi.Acq400(args.uuts[0])
+    acq400_hapi.cleanup.init()
+    if args.plot:
+        plt.ion()
+    
+    uut.s0.transient = 'POST=%d SOFT_TRIGGER=%d DEMUX=0' % \
+            (args.post, 1 if args.trg == 'int' else 0)    
+
+    for sx in uut.modules:
+        uut.modules[sx].trg = '1,1,1'  if args.trg == 'int' else '1,0,1'
+
+    if args.files != "":
+        work = awg_data.RunsFiles(uut, args.files.split(','), run_forever=True)
+    else:
+        work = awg_data.RainbowGen(uut, args.nchan, args.awglen, run_forever=True)
+        
+    store = store_file
+    loader = work.load()
+    for ii in range(0, args.loop):
+        print("shot: %d" % (ii))
+        f = loader.next()
+        print("Loaded %s" % (f))
+        uut.run_oneshot()
+        print("read_chan %d" % (args.post*args.nchan))
+        rdata = uut.read_chan(0, args.post*args.nchan)
+        store(ii, rdata, args.nchan, args.post)
+        if args.plot > 0 :
+            if args.plot == 1:
+                plt.cla()
+            plt.title("AI for shot %d %s" % (ii, "persistent plot" if args.plot > 1 else ""))
+            plot(ii, rdata, args.nchan, args.post)
+            
+    raw_input("hit return when done")
+
+
+def run_main():
+    parser = argparse.ArgumentParser(description='acq1001 HIL demo')
+    parser.add_argument('--files', default="", help="list of files to load")
+    parser.add_argument('--loop', type=int, default=1, help="loop count")        
+    parser.add_argument('--nchan', type=int, default=32, help='channel count for pattern')
+    parser.add_argument('--awglen', type=int, default=2048, help='samples in AWG waveform')
+    parser.add_argument('--post', type=int, default=100000, help='samples in ADC waveform')
+    parser.add_argument('--trg', default="int", help='trg "int|ext rising|falling"')
+    parser.add_argument('--plot', type=int, default=1, help='--plot 1 : plot data, 2: persistent')
+    parser.add_argument('uuts', nargs=1, help="uut ")
+    run_shots(parser.parse_args())
+
+# execution starts here
+
+if __name__ == '__main__':
+    run_main()
+