Added proper string sizing incl. null terminator

pyads/pyads_ex.py

@@ -835,11 +835,10 @@ def adsSyncReadReqEx2(
     index_group_c = ctypes.c_ulong(index_group)
     index_offset_c = ctypes.c_ulong(index_offset)
 
-    if type_is_string(data_type):
-        data = (STRING_BUFFER * PLCTYPE_STRING)()
-    elif type_is_wstring(data_type):
+    if type_is_wstring(data_type):
         data = (STRING_BUFFER * ctypes.c_uint8)()
     else:
+        # Regular string types already contain size too, rely on this type:
         data = data_type()
 
     data_pointer = ctypes.pointer(data)
@@ -861,11 +860,11 @@ def adsSyncReadReqEx2(
     if error_code:
         raise ADSError(error_code)
 
-    # If we're reading a value of predetermined size (anything but a string or wstring),
-    # validate that the correct number of bytes were read
+    # If we're reading a value of predetermined size (anything but wstring, regular
+    # strings also contain size), validate that the correct number of bytes were read
     if (
         check_length
-        and not(type_is_string(data_type) or type_is_wstring(data_type))
+        and not type_is_wstring(data_type)
         and bytes_read.value != data_length.value
     ):
         raise RuntimeError(

pyads/symbol.py

@@ -345,6 +345,10 @@ def get_type_from_str(type_str: str) -> Optional[Type[PLCDataType]]:
             scalar_type = AdsSymbol.get_type_from_str(scalar_type_str)
 
             if scalar_type:
+                if scalar_type == constants.PLCTYPE_STRING:
+                    # E.g. `STRING(80)` actually has a size of 81 including the string
+                    # terminator, so add one to the size
+                    size = size + 1
                 return scalar_type * size
 
         # We allow unmapped types at this point - Instead we will throw  an