diff -r 22a009561502 -r 2adfa4c60bff runtime/typemapping.py
--- a/runtime/typemapping.py	Fri Jan 19 19:58:44 2024 +0100
+++ b/runtime/typemapping.py	Sat Jan 20 11:41:17 2024 +0100
@@ -42,7 +42,7 @@
     "USINT":      _t(c_uint8),
     "BYTE":       _t(c_uint8),
     "STRING":     (IEC_STRING,
-                   lambda x: x.body[:x.len],
+                   lambda x: x.body[:x.len].decode(),
                    lambda t, x: t(len(x), x.encode() if type(x)==str else x)),
     "INT":        _t(c_int16),
     "UINT":       _t(c_uint16),