--Spindle Chiller RS232 control script
local mcSerial = {}
local inst = mc.mcGetInstance()

package.path = package.path .. ";./Modules/?.lua;"
package.cpath = package.cpath .. ";./Modules/?.dll;"
--package.cpath = "C:/src/Mach4/Modules/?.dll;"
rs232 = require("luars232")
socket = require("socket")

-------------------------------------------
--         Variables Declaration  		 --
-------------------------------------------
--gRegs0/ChillerStatus  	--Chiller status 1=on / 0=Standby
--gRegs0/WaterTemp  		--Actual water temp in Celsius
port_name = "COM5"		
ChillerCom = 0				--Chiller port status 1=open / 0=closed
SetTemp = 20				--Temp to set in Celsius
ChillerFault = 0
local MaxTemp = 50			--Alarm water temp in Celsius
Spindle_Overtemp = 0		--Chiller Water Overtemperature
local out = io.stderr

-------------------------------------------
--       Status Chiller Sync Cycle		 --
-------------------------------------------
function SyncChillerStatus()
GetFaults()
GetTemp()
	local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "WaterTemp"))
	local WTemp = mc.mcRegGetValue(hreg)
	if(WTemp >= MaxTemp) and (Spindle_Overtemp == 0)
	then
		mc.mcCntlSetLastError(inst, string.format("Cooling Water Overtemperature Alarm"))
		mc.mcCntlEStop(inst, 0);
		Spindle_Overtemp = 1
	elseif (WTemp <= MaxTemp) and (Spindle_Overtemp == 1)
	then
		Spindle_Overtemp = 0
	end
end
-------------------------------------------
--             Open Com Port             --
-------------------------------------------
function OpenChillerCom()
e, chiller = rs232.open(port_name)
	if e ~= rs232.RS232_ERR_NOERROR then
	-- handle error
	mc.mcCntlSetLastError(inst, string.format("can't open serial port '%s', error: '%s'\n",
			port_name, rs232.error_tostring(e)))
	return
	end
-- set port settings
assert(chiller:set_baud_rate(rs232.RS232_BAUD_9600) == rs232.RS232_ERR_NOERROR)
assert(chiller:set_data_bits(rs232.RS232_DATA_8) == rs232.RS232_ERR_NOERROR)
assert(chiller:set_parity(rs232.RS232_PARITY_NONE) == rs232.RS232_ERR_NOERROR)
assert(chiller:set_stop_bits(rs232.RS232_STOP_1) == rs232.RS232_ERR_NOERROR)
assert(chiller:set_flow_control(rs232.RS232_FLOW_OFF)  == rs232.RS232_ERR_NOERROR)
ChillerCom = 1
wx.wxMilliSleep(10) --Sleep 10 milliseconds
ChillerSet()
--mc.mcCntlSetLastError(inst, string.format("OK, port open with values '%s'\n", tostring(chiller)))
end
--------------------------------------------		
--             Close Com Port             --
 -------------------------------------------
function CloseChillerCom()
ChillerStandby()           --Set Remote Stop
assert(chiller:close() == rs232.RS232_ERR_NOERROR)
ChillerCom = 0
end

-------------------------------------------
-- Get chiller current water temperature --
-------------------------------------------
function GetTemp()
--mcSerial.FlushBuffer()
local reg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "ChillerStatus")) --Write ChillerStatus register status
	local Status = mc.mcRegGetValue(reg)
  if Status == 1
then
	ChillerComSend("c9")					--Ask temp remote running
else
	ChillerComSend("89")					--Ask temp remote Stopped
end
local read_len =1							-- read 2 bytes
timeout = 500 							    -- in miliseconds
local err, data_read, size = chiller:read(read_len, timeout)
assert(e == rs232.RS232_ERR_NOERROR)
local HSB = string.format("%02x",(string.byte(data_read)))
local err, data_read, size = chiller:read(read_len, timeout)
assert(e == rs232.RS232_ERR_NOERROR)
local LSB = string.format("%02x",(string.byte(data_read)))
Ftemp = (tonumber((LSB..HSB),16))*0.1			--hex to dec/*0.1 increments for degF
FahrenheitToCelsius(Ftemp)
local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "WaterTemp")) --Write WaterTemp register value
	mc.mcRegSetValue(hreg, CTemp)
end
-------------------------------------------
--     Set Temperature on chiller        --
-------------------------------------------
function ChillerSet()
	CelsiusToFahrenheit(SetTemp)
	TempToChiller(Htemp)
	--if ChillerStatus == 0
	--then
	ChillerComSend("a1")		--Send Chiller set point 1 temperature remote Stopped
	--else
	--ChillerComSend("e1")		--Send Chiller set point 1 temperature remote running
	--end
	ChillerComSend(SFtemp)
end

-------------------------------------------
--         Chiller Start Command         --
-------------------------------------------
function ChillerStart()
--ChillerSet()
ChillerComSend("e0")						--Set Remote Start
local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "ChillerStatus")) --Write ChillerStatus register status
	mc.mcRegSetValue(hreg, 1)
end

-------------------------------------------
--           Write to Serial			 --	
-------------------------------------------
function ChillerComSend(data)
local timeout = 100 						-- in miliseconds
err, len_written = chiller:write((data:gsub("%w%w", function(s) return string.char(tonumber(s, 16)) end)), timeout)
assert(e == rs232.RS232_ERR_NOERROR)
end

-------------------------------------------
--              Flush buffer             --
--Windows automatically fills a serial buffer with characters (up to 4096 I think)
--This function reads the entire buffer to empty it out
-------------------------------------------
function mcSerial.FlushBuffer()
	local RV = 0
	--RV, data_read, size = p:read(max_flush, timeout)
	RV = chiller:flush()
end

-------------------------------------------
-- Set chiller to Remote Stop{working}
-------------------------------------------
function ChillerStandby()
	ChillerComSend("a0")					--Set Remote Stop
	ChillerComSend("20")					--Set local control
	local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "ChillerStatus")) --Write ChillerStatus register status
	mc.mcRegSetValue(hreg, 0)
end

-------------------------------------------
-- Get chiller current setpoint{release}
-------------------------------------------
function GetSetpoint()
mcSerial.FlushBuffer()
local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "ChillerStatus")) --Write ChillerStatus register status
	local Status = mc.mcRegGetValueString(hreg)
  if Status == 0
then
	ChillerComSend("c1")					--Ask Setpoint remote running
else
	ChillerComSend("81")					--Ask Setpoint remote Stopped
end
local read_len = 2							-- read 2 bytes
timeout = 500   							-- in miliseconds
local err, data_read, size = chiller:read(read_len, timeout)
assert(e == rs232.RS232_ERR_NOERROR)
ChillerToTemp(data_read)
local Setpoint = CTemp
end
-------------------------------------------
-- Get chiller fault code(0 = no faults) --
-------------------------------------------
function GetFaults()
  --mcSerial.FlushBuffer()
	local hreg = mc.mcRegGetHandle(inst, string.format("gRegs0/%s", "ChillerStatus")) --Write ChillerStatus register status
	local Status = mc.mcRegGetValueString(hreg)  
	if Status == 0
	then
		ChillerComSend("c8")				--Ask faults remote running
	else
		ChillerComSend("88")				--Ask faults remote Stopped
	end
local read_len = 1							-- read 1 byte
timeout = 500   							-- in miliseconds
local err, data_read, size = chiller:read(read_len, timeout)
assert(e == rs232.RS232_ERR_NOERROR)
local fault = (string.byte(data_read))
	if fault ~= 0 and ChillerFault == 0		--0 = no faults/else check faults ChillerFaults()
	then
		mc.mcCntlSetLastError(inst, string.format("Chiller Fault No:'%s'\n", fault))
		ChillerFaults{fault}
		mc.mcCntlEStop(inst, 0);
	elseif (fault == 0)
	then
		ChillerFault = 0
	end
end
-------------------------------------------
--  Decode and show chiller fault code   --
-------------------------------------------
function ChillerFaults(HexFault)
	for _,v in ipairs(HexFault) do
		if v == 1 then mc.mcCntlSetLastError(inst, string.format("Chiller Water Level Low"))
	elseif v == 2 then mc.mcCntlSetLastError(inst, string.format("Chiller Fan Fail"))
	elseif v == 8 then mc.mcCntlSetLastError(inst, string.format("Chiller Pump Fail"))
	elseif v == 10 then mc.mcCntlSetLastError(inst, string.format("Chiller RTD Open"))	
	elseif v == 20 then mc.mcCntlSetLastError(inst, string.format("Chiller RTD Short"))
	elseif v == nil  then mc.mcCntlSetLastError(inst, string.format("Chiller Communication Fault"))
		end
	end
end

-------------------------------------------
--     Convert Fahrenheit to Celsius     --
-------------------------------------------
function FahrenheitToCelsius(temp)
  CTemp = (temp-32)*5/9
-- input >> temp
-- Call >> FahrenheitToCelsius(temp)  
end

-------------------------------------------
--    Convert Celsius to Fahrenheit      --
-------------------------------------------
function CelsiusToFahrenheit(SetTemp)
  Htemp = (SetTemp*9/5)+32
-- input >> SetTemp
-- Call >> CelsiusToFahrenheit(temp)
end

--------------------------------------------------------------------
--   Process data temp for send to chiller (F to 2 Bytes Hex)     --
--------------------------------------------------------------------
function TempToChiller(Htemp)
  temp = string.format("%04x",(Htemp*10))  	--farenheit*10 as 0xXXXX
--Invert Bytes  
  B1 = string.sub(temp,3,4)					--Extract last 2 digits of temp
  B1 = B1:gsub("%xx", function(s) return string.char(tonumber(s, 16)) end)  --convert to hex
  B2 = string.sub(temp,1,2)					--Extract first 2 digits of temp
  B2 = B2:gsub("%xx", function(s) return string.char(tonumber(s, 16)) end)  --convert to hex
  SFtemp = B1..B2
-- Call >> TempToChiller(68)
-- Out >> SFtemp  
end