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Mach4 General Discussion / Mach4 Coroutine within a Module

« on: March 22, 2020, 06:52:07 PM »

Hello all,
I created a module that backs a Lua panel I added to my Mach4 GUI. The panel allows the user to zero the work coordinates using a Z-axis/corner finding touch plate. I have the code/panel up and running using mcCntlGcodeExecuteWait() to submit gcode to Mach4.

I now want to refactor the code to use a coroutine to submit gcode to Mach4 but I'm having trouble getting this working. Modules have a separate scope from the ScreenScript / PLC Script and I believe this part of my problem. I cannot seem to pass/share the coroutine instance between the Screen Script/PLC Script and my Module.

Here's what I've tried so far

1) Initial Attempt -  create the coroutine within the Module and have the [PLC Script] call coroutine.resume(myCoroutine).
    REASON FOR FAILURE: myCoroutine variable has local scope within the module. The [PLC Script] does not have access to this variable and cannot call coroutine.resume(myCoroutine) as myCoroutine is always nil.

2) Second Attempt - create the coroutine (along with it's function block) within the [Screen Load] Script and call it from the Module and the [PLC Script]. Note that when I instantiate my panel I pass (what I believe to be a global reference to) the coroutine into my Module (see 'Panel Script' below)
    REASON FOR FAILURE: myCoroutine gets instantiated and the PLC Script seems to be able to call coroutine.resume(myCoroutine) just fine but the code
   within my Module that calls coroutine.resume(myCoroutine) (to start the function when the user presses the button) fails complaining that myCoroutine is a
   "bad argument #1 to 'resume' (thread expected)". My best guess here is that at the point my Module is loaded, the coroutine has not been created yet.
   
I've read all the Mach4 General forum threads containing the word 'coroutine' and can't find anything to resolve my confusion.
Any help would be greatly appreciated.
Thanks.

Code: [Select]

-- Screen Load Script
zTouchPlateCoroutine = coroutine.create(function (gCodeString)
local rc = mc.mcCntlGcodeExecute(INST, gCodeString)
coroutine.yield()
if rc ~= mc.MERROR_NOERROR then
error("gcode failed ["..gCodeString.."]", 2)
return "gcode failed", false
else
return "success", true
end
end)


Code: [Select]

-- Panel Script (gets inlined into the Screen Script)
function panelZTouch_Script(...)
    local inst = mc.mcGetInstance()
   
    -- Load the zTouchPlate module
    local profile = mc.mcProfileGetName(inst)
    local path = mc.mcCntlGetMachDir(inst)
    package.path = path .. "\\Modules\\zTouchPlate\\?.lua;"
    package.loaded.zTouchPlate = nil
   
    local ztp = require "zTouchPlate"

    -- Load UI and code to implement this panel
    ztp.create(zTouchPlateCoroutine)
end


Code: [Select]

-- PLC Script
if (zTouchPlateCoroutine ~= nil) and (machState == 0) then --zTouchPlate Coroutine exists and state == idle
    local state = coroutine.status(zTouchPlateCoroutine)
    if state == "suspended" then --zTouchPlate Coroutine is suspended
        coroutine.resume(zTouchPlateCoroutine)
    end
end