InstrumentChannel: allow None sites

Allow site to be None (still must be explicitly specified). If the site
is None, the label if created using only the measurement type.
1 file changed
tree: 735bf49ed1931d841d1e4b364225d51606a83657
  1. devlib/
  2. doc/
  3. src/
  4. .gitignore
  5. README.rst
  6. setup.py