Lua EPICS Module¶
The lua EPICS Module is an embedding of the lua language interpreter into an EPICS IOC. From there, the interpreter is exposed to the user in the form of the luascript record, which uses the interpreter to allow for scriptable record support; the lua shell, an addition to or replacement of the ioc shell; and functions to allow easy use of lua in other modules.
Currently, the lua module uses lua version 5.4.0. A reference manual describing the details of the language can be found here.
luascriptRecord¶
The luascript record type provides customizeable record behavior in much the same way as the calcout or scalcout record. Every time the record is processeed, lua code is executed and any returned variables are outputted to an OUT_LINK. The record has both double and string input links that get exposed as global variables for the code to use.
The record has access to a set of library functions that allow it to get and put values from other PV’s or asyn port parameters, sleep, call iocsh functions, send commands to a device, or you can bind your own functions to extend its functionality.
Full documentation can be found here
luaPortDriver¶
luaPortDriver support is included to generate asynPortDrivers with parameters generated from a lua script. Each parameter gets snippets of lua code associated with its reading and writing that get called when the asyn callbacks are triggered.
Full documentation can be found here
lua Shell¶
The lua shell is an alternate shell to either the vxWorks or ioc shell environment. It has all the same functionality of those shells, while also providing the ability to conditionally execute code, calculate necessary values, construct loops over code, and define functions within startup scripts.
The lua Shell is able to access all the same epics lua libraries as the luascriptRecord, including any functions or libraries that you build yourself into your IOC. The shell even implicitly loads the iocsh library, which means you can call iocsh-registered functions in the lua shell exactly like you would in the ioc shell.