Fix example (#452)

* Add missing import

* Fix missing variables

Author: FiloCara

example/boolean.py

@@ -35,7 +35,10 @@
 
 
 # play with these functions.
-plc.read_area(areas['MK'], dbnumber, start, size)
-plc.write_area(areas['MK'], dbnumber, start, size)
+plc.read_area(area=areas['MK'], dbnumber=0, start=20, size=2)
+
+data = bytearray()
+snap7.util.set_int(data, 0, 127)
+plc.write_area(area=areas['MK'], dbnumber=0, start=20, data=data)
 # read the client source code!
 # and official snap7 documentation

example/read_multi.py

@@ -9,6 +9,7 @@
 import snap7
 from snap7.common import check_error
 from snap7.types import S7DataItem, S7AreaDB, S7WLByte
+from snap7 import util
 
 client = snap7.client.Client()
 client.connect('10.100.5.2', 0, 2)