diff --git a/site_ansto/instrument/util/gen_sct.py b/site_ansto/instrument/util/gen_sct.py
index ca69520b..229cf991 100755
--- a/site_ansto/instrument/util/gen_sct.py
+++ b/site_ansto/instrument/util/gen_sct.py
@@ -1086,9 +1086,12 @@ def put_preamble(MyDriver):
     txt += ['  set catch_status [ catch {']
     txt += ['    set debug_threshold [hgetpropval ${tc_root} debug_threshold]']
     txt += ['    if {${debug_level} >= ${debug_threshold}} {']
-    txt += ['      set fd [open "../log/%s_[basename ${tc_root}].log" "a"]' % MyDriver['name']]
-    txt += ['      set line "[clock format [clock seconds] -format "%T"] ${debug_string}"']
-    txt += ['      puts ${fd} "${line}"']
+    txt += ['      set now [clock seconds]']
+    txt += ['      set ts [clock format ${now} -format "%Y%m%d"]']
+    txt += ['      set log_file_name "../log/%s_[basename ${tc_root}]_${ts}.log"' % MyDriver['name']]
+    txt += ['      set fd [open "${log_file_name}" "a"]']
+    txt += ['      set ts [clock format ${now} -format "%T"]']
+    txt += ['      puts ${fd} "${ts} ${debug_string}"']
     txt += ['      close ${fd}']
     txt += ['    }']
     txt += ['  } catch_message ]']