diff --git a/script/optics/PhotonFluxSpectrum.py b/script/optics/PhotonFluxSpectrum.py
index a4669ea3..5fd8a9c8 100644
--- a/script/optics/PhotonFluxSpectrum.py
+++ b/script/optics/PhotonFluxSpectrum.py
@@ -36,6 +36,8 @@ elif RANGE == "C K-edge":
 KEI_DIODE = "X03DA-KEITHLEY-1:"
 KEI_RMU = "X03DA-KEITHLEY-2:"
 
+prepare_keithleys(DWELL)
+
 if BEAM == "G600 1x1":
     # G600 1x1 reference sscan_2268 (elog:119)
     #SampleCurrentGain.write("L, 10^7")
@@ -103,6 +105,5 @@ def trig():
 POSITIONERS = (Eph)
 SENSORS = (Keithley1, Keithley2, SampleCurrent, RefCurrent, MachineCurrent)
 
-prepare_keithleys(DWELL)
 lscan(POSITIONERS, SENSORS, STARTPOS, ENDPOS, STEPS, LATENCY, before_read=before_readout, after_read=after_readout)