diff --git a/script/optics/ExitSlitYScan.py b/script/optics/ExitSlitYScan.py
index c0aa2591..8fa51df3 100644
--- a/script/optics/ExitSlitYScan.py
+++ b/script/optics/ExitSlitYScan.py
@@ -12,6 +12,14 @@ STEPS = 0.01
 LATENCY = 0.1
 DWELL = 1.0
 
-set_adc_averaging(dwelltime=DWELL)
-lscan(POSITIONERS, SENSORS, STARTPOS, ENDPOS, STEPS, LATENCY, before_read=before_readout, after_read=after_readout)
+def trig():
+    wait_beam()
+    #caput(KEI_RMU + "DOINIT", 1)
+    #time.sleep(0.1)
+    #caput(KEI_RMU + "DOTRIGGER", 1)
+    time.sleep(DWELL * 1.1)
+    #caput(KEI_RMU + "DOFETCH", 1)
+
+set_adc_averaging(dwelltime=DWELL)
+lscan(POSITIONERS, SENSORS, STARTPOS, ENDPOS, STEPS, LATENCY, before_read=trig, after_read=after_readout)