caffi is the Channel Access Foreign Function Interface. It uses CFFI to call EPICS channel access library.
This package provides direct low level interface to channel access, alike the C API.
Warning
On certain platforms, callback might not work. On macOS arm64 platform, the module fails in import and is unusable.
EPICS dynamic libraries have been shipped with the package for Windows, Linux and macOS.
But if the environment variables EPICS_BASE and EPICS_HOST_ARCH are set on macOS and Linux,
those libraries under path ${EPICS_BASE}/lib/${EPICS_HOST_ARCH} will be used.
Either use pip,
$ pip install caffi
or checkout source code from the git repository,
$ git clone https://github.com/CaChannel/caffi.git $ cd caffi $ python setup.py install
The SPEC file python-caffi.spec is included. Get the source tarball either from PyPI or create it by python setup.py sdist, and run:
$ rpmbuild -ta caffi-1.0.0.tar.gz
The binary and source RPM will be created. The package name is python-caffi.
The recipe is included.:
$ conda build conda-recipe
Latest documents are hosted at Read the Dcos.
import caffi.ca as ca
status = ca.create_context()
assert status == ca.ECA.NORMAL
status, chid = ca.create_channel('catest')
assert status == ca.ECA.NORMAL
status = ca.pend_io(3)
assert status == ca.ECA.NORMAL
status = ca.put(chid, 123)
status = ca.flush_io()
status, value = ca.get(chid)
assert status == ca.ECA.NORMAL
status = ca.pend_io(3)
assert status == ca.ECA.NORMAL
assert value.get() == 123