Add A,B,C option to check_chan()

sohstationviewer/controller/util.py

@@ -349,7 +349,7 @@ def check_chan(chan_id: str, req_soh_chans: List[str], req_wf_chans: List[str],
     """
     if chan_id.startswith('VM'):
         if (not include_mp123zne and
-                chan_id[-1] in ['1', '2', '3', 'Z', 'N', 'E']):
+                chan_id[-1] in ['1', '2', '3', 'Z', 'N', 'E', 'A', 'B', 'C']):
             return False
         if (not include_mp456uvw
                 and chan_id[-1] in ['4', '5', '6', 'U', 'V', 'W']):