diff --git a/site_ansto/hardsup/Monitor/Pulser.c b/site_ansto/hardsup/Monitor/Pulser.c
index c465353b..bcd92ef3 100644
--- a/site_ansto/hardsup/Monitor/Pulser.c
+++ b/site_ansto/hardsup/Monitor/Pulser.c
@@ -162,7 +162,10 @@ int main(int argc, char* argv[])
     /*********************************************/
     DAQmxErrChk (DAQmxStartTask(taskHandle));
 
-    sleep(sleep_time);
+    do {
+      sleep(sleep_time);
+    } while (range == 0);
+
     DAQmxStopTask(taskHandle);
     DAQmxClearTask(taskHandle);
     taskHandle = 0;