diff --git a/lmwsip/__init__.py b/lmwsip/__init__.py
index 357991b..ba97e3e 100644
--- a/lmwsip/__init__.py
+++ b/lmwsip/__init__.py
@@ -208,6 +208,7 @@ Support for:
         'ZV10S': ('WN', 1, 10),
         'WI': ('BL', 8, 10),
         'xBS10S': ('WN', 1, 10),
+        'xBS1S': ('WN', 1, 1),
         'xBS10s': ('WN', 1, 10),
         'xC10P': ('WN', 1, 10),
         'xCHL10': ('WN', 1, 10),
@@ -563,13 +564,14 @@ Opens the connection and logs in.
         # because we use GMT +1 (MET, UTC-1)
         #
         now=time.time()
-        if (parameter.find("10") != -1):
+        period = self.period(parameter)
+        if (period == 10):
             dt = now%600
             if (dt < 330):
                 now = 3000 + now - dt
             else:
                 now = 3600 + now - dt
-        else:
+        elif (period == 1):
             #
             # e.g. H1 use 30 seconds to calculate the time.
             #
@@ -578,6 +580,9 @@ Opens the connection and logs in.
                 now = 3540 + now - dt
             else:
                 now = 3600 + now - dt
+        else:
+           # At the moment no support for parameters other than 1 or 10 minutes.
+           raise LmwParmWarn(parameter)
         time_of_day=time.strftime("%H:%M", time.gmtime(now))
         return { "day": time.strftime("%d-%m-%Y", time.gmtime(now)),
                  "time_of_day": time.strftime("%H:%M", time.gmtime(now)) }