diff --git a/ObservationSim/Config/ChipOutput.py b/ObservationSim/Config/ChipOutput.py
index 5fb00a8686ebf84c7b514b8da1d83df6cc59f05b..fb3110bb07c5c04838a23d2d7b2f71cf384a9e42 100755
--- a/ObservationSim/Config/ChipOutput.py
+++ b/ObservationSim/Config/ChipOutput.py
@@ -23,12 +23,12 @@ class ChipOutput(object):
         
         # self.cat_name = 'MSC_' +  config["obs_setting"]["date_obs"] + config["obs_setting"]["time_obs"] + "_" + str(pointing_ID).rjust(7, '0') + "_" + self.chipLabel.rjust(2,'0') + ".cat"
 
-        self.cat_name = "MSC_%s_chip_%s_filt_%s"%(str(pointing_ID).rjust(7, '0'), focal_plane.getChipLabel(chip.chipID), filt.filter_type) + ".cat"
+        self.cat_name = "MSC_1%s_chip_%s_filt_%s"%(str(pointing_ID).rjust(7, '0'), focal_plane.getChipLabel(chip.chipID), filt.filter_type) + ".cat"
 
         self.subdir = subdir
 
         # Setup logger for each chip
-        logger_filename = "MSC_%s_chip_%s_filt_%s"%(str(pointing_ID).rjust(7, '0'), focal_plane.getChipLabel(chip.chipID), filt.filter_type) + ".log"
+        logger_filename = "MSC_1%s_chip_%s_filt_%s"%(str(pointing_ID).rjust(7, '0'), focal_plane.getChipLabel(chip.chipID), filt.filter_type) + ".log"
         self.logger = logging.getLogger()
         fh = logging.FileHandler(os.path.join(self.subdir, logger_filename), mode='w+', encoding='utf-8')
         fh.setLevel(logging.DEBUG)