diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index f66df6125268a780f6eb7fc42f59213aaba33582..0348a1371131583c9be04d1a4f967f7767275abe 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -33,7 +33,7 @@ from csst_dfs_api.sls.level2spectra import Level2SpectraApi as SlsLevel2DataApi
 from .logger import get_logger
 from .params import CSST_PARAMS as CP
 from .params import DFS_CONF
-from .time import now, now_dfs
+from .time import now
 
 
 class CsstMsDataManager:
@@ -385,7 +385,7 @@ class CsstMsDataManager:
             raise FileNotFoundError(f"No file found with pattern {pattern} in {dir_l0}")
 
         # parse filename
-        if ver_sim == "C6.2":
+        elif ver_sim in ["C5.2", "C6.1"]:
             pattern = re.compile(
                 r"(?P<telescope>[A-Z]+)_"
                 r"(?P<instrument>[A-Z]+)_"
@@ -393,17 +393,17 @@ class CsstMsDataManager:
                 r"(?P<obs_type>[A-Z]+)_"
                 r"(?P<exp_start>[0-9]{14})_"
                 r"(?P<exp_stop>[0-9]{14})_"
-                r"(?P<obs_id>[0-9]{11})_"
+                r"(?P<obs_id>[0-9]{9})_"
                 r"(?P<detector>[0-9]{2})_"
                 r"L(?P<level>[0-9]{1})_"
-                r"V(?P<version>[0-9]{2})"
+                r"(?P<version>[0-9]{1})"
                 r".(?P<ext>[a-z]{4})"
             )
             mo = re.fullmatch(pattern, fps_img[0])
             assert mo is not None
             mogd = mo.groupdict()
             mogd.pop("detector")
-        elif ver_sim == "C5.2":
+        else:
             pattern = re.compile(
                 r"(?P<telescope>[A-Z]+)_"
                 r"(?P<instrument>[A-Z]+)_"
@@ -411,10 +411,10 @@ class CsstMsDataManager:
                 r"(?P<obs_type>[A-Z]+)_"
                 r"(?P<exp_start>[0-9]{14})_"
                 r"(?P<exp_stop>[0-9]{14})_"
-                r"(?P<obs_id>[0-9]{9})_"
+                r"(?P<obs_id>[0-9]{11})_"
                 r"(?P<detector>[0-9]{2})_"
                 r"L(?P<level>[0-9]{1})_"
-                r"(?P<version>[0-9]{1})"
+                r"V(?P<version>[0-9]{2})"
                 r".(?P<ext>[a-z]{4})"
             )
             mo = re.fullmatch(pattern, fps_img[0])
@@ -477,7 +477,7 @@ class CsstMsDataManager:
     def l0_detector(self, detector=6):
         """ L0 detector-specific image file path """
         assert detector in self.available_detectors
-        if self.ver_sim == "C5.2":
+        if self.ver_sim in ["C5.2", "C6.1"]:
             fn = f"{self.telescope}_{self.instrument}_{self.project}_{self.obs_type}_{self.exp_start}_" \
                  f"{self.exp_stop}_{self.obs_id}_{detector:02d}_L{self.level}_{self.version}.{self.ext}"
         else:
@@ -517,7 +517,7 @@ class CsstMsDataManager:
 
         """
         assert detector in self.available_detectors
-        if self.ver_sim == "C5.2":
+        if self.ver_sim in ["C5.2", "C6.1"]:
             fn = f"{self.telescope}_{self.instrument}_{self.project}_{self.obs_type}_{self.exp_start}_{self.exp_stop}_" \
                  f"{self.obs_id}_{detector:02d}_{post}"
         else: