diff --git a/site_ansto/instrument/bilby/config/chopper/chopper.tcl b/site_ansto/instrument/bilby/config/chopper/chopper.tcl
index 80394e93..b1225105 100644
--- a/site_ansto/instrument/bilby/config/chopper/chopper.tcl
+++ b/site_ansto/instrument/bilby/config/chopper/chopper.tcl
@@ -36,3 +36,17 @@ if {$sim_mode == false} {
 sicslist setatt t0_chopper_id klass NXdisk_chopper
 sicslist setatt t0_chopper_id long_name t0_chopper_id
 sicslist setatt t0_chopper_id mutable true
+
+if [dict exists $::config_dict disk_chopper name] {
+  set ch_name [dict get $::config_dict disk_chopper name]
+} else {
+  clientput ERROR: Chopper configuration is missing
+}
+::utility::macro::getset float t0_chopper_freq [subst { {chopper $ch_name} }] {
+  set cid [SplitReply [t0_chopper_id]]
+  set rpm [hval /instrument/$chopper/disk_$cid/aspeed]
+  return [expr $rpm / 60.0]
+}
+sicslist setatt t0_chopper_freq klass NXdisk_chopper
+sicslist setatt t0_chopper_freq long_name t0_chopper_freq
+sicslist setatt t0_chopper_freq mutable true