compatible with CPIC file format

csst_common/file.py

@@ -49,7 +49,7 @@ class File:
             r"(?P<exp_start>[0-9]{14})_"
             r"(?P<exp_stop>[0-9]{14})_"
             r"(?P<obs_id>[0-9]{11,14})_"
-            r"(?P<detector>[0-9]+)_"
+            r"(?P<detector>[0-9A-Z]+)_"
             r"L(?P<level>[0-9]{1})_"
             r"V(?P<version>[0-9]{2})"
             r"(?P<ext>[a-z.]+)"