L2SS-698: Add graphviz state diagram to device documentation

tangostationcontrol/docs/source/conf.py

@@ -28,6 +28,7 @@ author = 'Stichting ASTRON'
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
+    "sphinx.ext.graphviz"
 ]
 
 # Add any paths that contain templates here, relative to this directory.

tangostationcontrol/docs/source/devices/using.rst

@@ -25,6 +25,33 @@ The state of a device is then queried with ``device.state()``. Each device can b
 - ``DevState.FAULT``: The device is malfunctioning. Functionality cannot be counted on.
 - The ``device.state()`` function can throw an error, if the device cannot be reached at all. For example, because it's docker container is not running. See the :ref:`docker` device on how to start it.
 
+
+.. graphviz::
+
+    digraph finite_state_machine {
+        fontname="Helvetica,Arial,sans-serif"
+        node [fontname="Helvetica,Arial,sans-serif"]
+        edge [fontname="Helvetica,Arial,sans-serif"]
+        rankdir=LR;
+        node [shape = doublecircle fixedsize=true width=0.7]; off;
+        node [shape = circle fixedsize=true width=0.9];
+        init -> off [label = "user", color="red"];
+        standby -> off [label = "user", color="red"];
+        on -> off [label = "user", color="red"];
+        alarm -> off [label = "user", color="red"];
+        off -> init [label = "device", color="green"];
+        init -> standby [label = "device", color="green"];
+        standby -> on [label = "device", color="green"];
+        on -> alarm [label = "device", color="green"];
+        init -> fault [label = "device", color="green"];
+        standby -> fault [label = "device", color="green"];
+        on -> fault [label = "device", color="green"];
+        alarm -> fault [label = "device", color="green"];
+        fault -> init [label = "user", color="red"];
+        fault -> off [label = "user", color="red"];
+    }
+
+
 Each device provides the following commands to change the state:
 
 :boot(): Turn on the device, and initialise the hardware. Moves from ``OFF`` to ``ON``.

tangostationcontrol/requirements.txt

@@ -13,4 +13,6 @@ docker >= 5.0.3 # Apache 2
 python-logstash-async >= 2.3.0 # MIT
 python-casacore >= 3.3.1 # LGPLv3
 etrs-itrs@git+https://github.com/brentjens/etrs-itrs # license pending
+# numpy must be manually added even though etrs-itrs requires it
+numpy >= 1.22.0 # BSD
 lofarantpos >= 0.5.0 # Apache 2