Assert motor sign is -1 or 1
Setting motor sign to 0 may lead to wrong position calculation. Assert motor sign is -1 or 1. Fix #1345 (closed).
It works as following:
Door_zreszela_1 [1]: mot01.sign = 1
Door_zreszela_1 [2]: mot01.sign = -2
PyDs_PythonError: AssertionError: sign must be either -1 or 1 (not -2)
(For more detailed information type: tango_error)
Door_zreszela_1 [3]: mot01.sign = -1
Door_zreszela_1 [4]: mot01.sign = 0
PyDs_PythonError: AssertionError: sign must be either -1 or 1 (not 0)
(For more detailed information type: tango_error)
@sardana-org/integrators could you please review. Many thanks!