dls-plc-tools 1.0.0b1

A collection of tools to facilitate EPICS commissioning of PLC based systems

dls_plc_tools

Tools for interrogating Omron NX PLCs over EtherNet/IP, to support EPICS commissioning of PLC-based vacuum systems at Diamond Light Source.

They let you browse the tags a PLC publishes, inspect the layout of its structures, and watch values update live — without a Sysmac Studio licence or physical access to the controller. Everything is read-only explicit messaging: the same mechanism the EPICS ether_ip driver uses, serviced in the controller's spare time, so it is safe to run against production PLCs.

There are two front-ends over the aphyt library: a command-line tool (dls-read-plc) and a PySide6 desktop GUI (dls-read-plc-gui).

What	Where
Source	https://github.com/DiamondLightSource/dls-plc-tools
PyPI	pip install dls-plc-tools
Docker	docker run ghcr.io/diamondlightsource/dls-plc-tools:latest
Releases	https://github.com/DiamondLightSource/dls-plc-tools/releases

Command-line tool

With just an IP address, dls-read-plc discovers every published structure tag on the PLC and summarises each one — its member layout and how many instances are actually in use:

dls-read-plc 172.23.x.x

Other modes:

dls-read-plc 172.23.x.x -l              # list every published tag and its type
dls-read-plc 172.23.x.x -s Seq          # show one structure's members and array bounds
dls-read-plc 172.23.x.x -d Seq          # live-updating table of a structure's values
dls-read-plc 172.23.x.x -d Seq -m Desc,State,Status   # choose which members to watch

--detail/-d redraws a table every 2 seconds (floor 0.5 s, set with --interval), highlighting cells that have changed. Press Ctrl-C to stop. See dls-read-plc --help for the full option list.

GUI

dls-read-plc-gui 172.23.x.x

dls-read-plc-gui gives you a browsable list of the PLC's published tags, a live table of a selected structure's values (changed cells flash amber), and an export of the discovered structure layouts to an Excel spreadsheet. The IP address argument is optional — you can also enter it in the window.

Installation

pip install dls-plc-tools

Or, for development, using uv:

git clone https://github.com/DiamondLightSource/dls-plc-tools.git
cd dls-plc-tools
uv sync
uv run dls-read-plc <ip>

Notes

• These tools only ever read. They never write to the controller, never start a keep-alive poll, and keep at most one request in flight. Poll rates default to ~2 s and are floored at 0.5 s.
• Tags are visible over EtherNet/IP only if they are globals with Network Publish set in Sysmac Studio, plus the controller's _-prefixed system variables. Enumeration uses Omron's Tag Name Server object (CIP class 0x6A).
• DLS structures are structure-of-arrays: Seq.Interfc[1] is instance 1, with index 0 reserved as padding. A non-empty Desc entry marks an instance that is actually in use.