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+# Anton-Paar iSorb HP
+
+This is a gas adsorption system, used on WISH and also used in the Hydrogen lab.
+
+The principle of operation is to 'dose' gas into a porous material, and measure the rate at which that gas gets adsorbed onto that material. When used on a beamline, we also want to perform neutron measurements between doses.
+
+The iSorb has no native communication interface (despite the manufacturer having been asked for this). Our EPICS support module is implemented in an unusual way:
+- There is a program running on the manufacturer PC, alongside the manufacturer software
+- This program uses a combination of GUI automation and log-scraping to extract information of interest from the manufacturer software
+- This information is then exposed over standard HTTP endpoints
+- A usual StreamDevice IOC communicates with these HTTP endpoints
+
+## PC and manufacturer software
+
+The manufacturer software is called `iSorb HPwin` and runs on the equipment-specific PC associated with this system.
+
+:::{important}
+The experiment controls team does not maintain the Windows or manufacturer software installation on this PC; that is done by the equipment owners.
+:::
+
+## Local control script (`isorb.py`)
+
+This script is software which the experiment controls group has written, and runs on the PC alongside the manufacturer software.
+
+To run it, check out [the support module](https://github.com/isisComputingGroup/epics-isorbhp) locally on the manufacturer PC into `C:\Users\User\isorb-hp`, ensure `uv` is available, and then run:
+
+```
+cd C:\Users\User\isorb-hp
+uv run isorb.py
+```
+
+This will ensure a suitable Python version is used and that dependencies are automatically downloaded.
+
+This script is implemented using FastAPI and exposes standard HTTP endpoints on port `8000`.
+
+## IOC & support module
+
+The IOC and support module run on the NDX in the typical way. The IOC uses streamdevice to poll the HTTP endpoints exposed by the `isorb.py` script.
+
+## Troubleshooting
+
+### GUI actions (pause/resume) do not work
+
+This relies on UI automation, via `pywinauto`. This means that it is sensitive to the state of
+the manufacturer software UI. Ensure that:
+- The manufacturer software is open, maximised, and in focus
+- There are no additional windows 'in front' of the main UI (which shows a diagram including the manifold and various valves)
+
+You can see stack traces by logging on to the equipment-specific PC and checking the logs emitted by the `isorb.py` script; these may give further hints about why the UI automation is failing.
diff --git a/doc/spelling_wordlist.txt b/doc/spelling_wordlist.txt
index 76420db5b2..8f13b3d685 100644
--- a/doc/spelling_wordlist.txt
+++ b/doc/spelling_wordlist.txt
@@ -395,6 +395,7 @@ isisstat
 isissupport
 iso
 isobus
+iSorb
 ITC
 iTC
 itc