diff --git a/internal/test_unit/config/Ascii2NcConfig_rain_01H_sum b/internal/test_unit/config/Ascii2NcConfig_rain_01H_sum
new file mode 100644
index 0000000000..ca7aafdf4d
--- /dev/null
+++ b/internal/test_unit/config/Ascii2NcConfig_rain_01H_sum
@@ -0,0 +1,52 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// ASCII2NC configuration file.
+//
+// For additional information, please see the MET User's Guide.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+//
+// The parameters listed below are used to summarize the ASCII data read in
+//
+
+//
+// Time periods for the summarization
+// obs_var (string array) is added and works like grib_code (int array)
+// when the obs name is given instead of grib_code
+//
+
+time_summary = {
+  flag = TRUE;
+  raw_data = FALSE;
+  beg = "00";
+  end = "23";
+  step = 3600;
+  width = { beg = -3599; end = 1; }
+  grib_code = [ ];
+  obs_var   = [ "rain" ];
+  type = [ "sum" ];
+  vld_freq = 15*60;
+  vld_thresh = 1.0;
+}
+
+//
+// Mapping of input little_r report types to output message types
+//
+message_type_map = [
+   { key = "FM-12 SYNOP";  val = "ADPSFC"; },
+   { key = "FM-13 SHIP";   val = "SFCSHP"; },
+   { key = "FM-15 METAR";  val = "ADPSFC"; },
+   { key = "FM-18 BUOY";   val = "SFCSHP"; },
+   { key = "FM-281 QSCAT"; val = "ASCATW"; },
+   { key = "FM-32 PILOT";  val = "ADPUPA"; },
+   { key = "FM-35 TEMP";   val = "ADPUPA"; },
+   { key = "FM-88 SATOB";  val = "SATWND"; },
+   { key = "FM-97 ACARS";  val = "AIRCFT"; }
+];
+
+//
+// Indicate a version number for the contents of this configuration file.
+// The value should generally not be modified.
+//
+version = "V11.0.0";
diff --git a/internal/test_unit/xml/unit_ascii2nc.xml b/internal/test_unit/xml/unit_ascii2nc.xml
index feef57c65d..01322961a8 100644
--- a/internal/test_unit/xml/unit_ascii2nc.xml
+++ b/internal/test_unit/xml/unit_ascii2nc.xml
@@ -101,4 +101,20 @@
     </output>
   </test>
 
+  <test name="ascii2nc_rain_01H_sum">
+    <exec>&MET_BIN;/ascii2nc</exec>
+    <param> \
+      &DATA_DIR_OBS;/ascii/aws/aws_20220609_020000.txt \
+      &DATA_DIR_OBS;/ascii/aws/aws_20220609_021500.txt \
+      &DATA_DIR_OBS;/ascii/aws/aws_20220609_023000.txt \
+      &DATA_DIR_OBS;/ascii/aws/aws_20220609_024500.txt \
+      &DATA_DIR_OBS;/ascii/aws/aws_20220609_030000.txt \
+      &OUTPUT_DIR;/ascii2nc/aws_2022060903_rain_01H_sum.nc \
+      -config &CONFIG_DIR;/Ascii2NcConfig_rain_01H_sum
+    </param>
+    <output>
+      <point_nc>&OUTPUT_DIR;/ascii2nc/aws_2022060903_rain_01H_sum.nc</point_nc>
+    </output>
+  </test>
+
 </met_test>