diff --git a/site_ansto/instrument/reflectometer/extraconfig.tcl b/site_ansto/instrument/reflectometer/extraconfig.tcl
index e69de29b..ec38a3a2 100644
--- a/site_ansto/instrument/reflectometer/extraconfig.tcl
+++ b/site_ansto/instrument/reflectometer/extraconfig.tcl
@@ -0,0 +1,38 @@
+VarMake detector_distance Float User
+VarMake detector_base Float User
+VarMake slit4_distance Float User
+VarMake slit4_base Float User
+VarMake sample_distance Float User
+VarMake sample_base Float User
+VarMake slit3_distance Float User
+VarMake slit3_base Float User
+
+detector_distance 10000
+detector_base 300
+slit4_distance 6000
+slit4_base 20
+sample_distance 5800
+sample_base 50
+slit3_distance 5600
+slit3_base 20
+
+proc set_two_theta { arg } {
+  set d1 [expr [SplitReply [detector_distance]] - [SplitReply [sample_distance]]]
+  set d2 [expr [SplitReply [slit4_distance]] - [SplitReply [sample_distance]]]
+  set h1 [expr [SplitReply [detector_base]] + $d1 * tan($arg)]
+  set h2 [expr [SplitReply [slit4_base]] + $d2 * tan($arg)]
+  return "dz=$h1,st4vt=$h2"
+}
+publish set_two_theta user
+
+proc get_two_theta {} {
+  set d1 [expr [SplitReply [detector_distance]] - [SplitReply [sample_distance]]]
+  set h1 [expr [SplitReply [dz]] - [SplitReply [detector_base]]]
+  return [expr atan2($h1, $d1)]
+}
+publish get_two_theta user
+
+MakeConfigurableMotor two_theta
+two_theta readscript get_two_theta
+two_theta drivescript set_two_theta
+