diff --git a/site_ansto/instrument/config/scan/scan_common_1.tcl b/site_ansto/instrument/config/scan/scan_common_1.tcl
index cfec12db..0b206318 100644
--- a/site_ansto/instrument/config/scan/scan_common_1.tcl
+++ b/site_ansto/instrument/config/scan/scan_common_1.tcl
@@ -446,9 +446,17 @@ namespace eval scan {
       ::histogram_memory::count_size $preset
       hmscan clear 
       hmscan add $scanvar $start $step
-    } else {
+    } elseif {$det_type == "bmon"} {
+      set mode [string tolower $mode]
+      switch -glob $mode {
+        "time"    { set bms_mode "timer" }
+        "monitor" { set bms_mode "monitor" }
+        default   {return -code error "ERROR: mode should be  'time' or 'monitor' not $mode"}
+      }
       bmonscan clear 
       bmonscan add $scanvar $start $step
+    } else {
+      return -code error "ERROR: detector type should be 'histmem' or 'bmon' not $det_type"
     }
     ::scan::runscan_cmd -set numpoints $numpoints
     ::scan::runscan_cmd -set scan_variable $scanvar
@@ -460,7 +468,7 @@ namespace eval scan {
     if {$det_type == "histmem"} {
       hmscan run $numpoints timer 0
     } else {
-      bmonscan run $numpoints $mode $preset
+      bmonscan run $numpoints $bms_mode $preset
     }
   } message ] {
     set force_scan false