Add len parameter to decode_bits. (#1062)

Author: janiversen

pymodbus/payload.py

@@ -373,9 +373,9 @@ def decode_8bit_uint(self):
         handle = make_byte_string(handle)
         return unpack(fstring, handle)[0]
 
-    def decode_bits(self):
+    def decode_bits(self, package_len=1):
         """Decode a byte worth of bits from the buffer."""
-        self._pointer += 1
+        self._pointer += package_len
         # fstring = self._endian + "B"
         handle = self._payload[self._pointer - 1 : self._pointer]
         handle = make_byte_string(handle)