struct.error: argument for 's' must be a bytes object

[Lstick]

When I run pymodbus-1.3.0-rc2 with debug activate, I have this error:

builder.add_string('abcdefgh')
File "/usr/lib64/python3.4/site-packages/pymodbus-1.3.0rc2-py3.4.egg/pymodbus/payload.py", line 179, in add_string
struct.error: argument for 's' must be a bytes object

Code is:
builder = BinaryPayloadBuilder(endian=Endian.Little)

builder.add_string('abcdefgh')

payload = builder.build()

[dhoomakethu]

if you are using python3 , pass the string as bytestring ,
builder.add_string(b'abcdefgh')

[Lstick]

Thanks a lot!