cc-mek-scada/rtu/modbus.lua
2022-05-12 15:36:27 -04:00

441 lines
15 KiB
Lua

local comms = require("scada-common.comms")
local types = require("scada-common.types")
local modbus = {}
local MODBUS_FCODE = types.MODBUS_FCODE
local MODBUS_EXCODE = types.MODBUS_EXCODE
-- new modbus comms handler object
---@param rtu_dev rtu_device|rtu_rs_device RTU device
---@param use_parallel_read boolean whether or not to use parallel calls when reading
modbus.new = function (rtu_dev, use_parallel_read)
local self = {
rtu = rtu_dev,
use_parallel = use_parallel_read
}
---@class modbus
local public = {}
local insert = table.insert
---@param c_addr_start integer
---@param count integer
---@return boolean ok, table readings
local _1_read_coils = function (c_addr_start, count)
local tasks = {}
local readings = {}
local access_fault = false
local _, coils, _, _ = self.rtu.io_count()
local return_ok = ((c_addr_start + count) <= coils) and (count > 0)
if return_ok then
for i = 1, count do
local addr = c_addr_start + i - 1
if self.use_parallel then
insert(tasks, function ()
local reading, fault = self.rtu.read_coil(addr)
if fault then access_fault = true else readings[i] = reading end
end)
else
readings[i], access_fault = self.rtu.read_coil(addr)
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
end
-- run parallel tasks if configured
if self.use_parallel then
parallel.waitForAll(table.unpack(tasks))
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
end
else
readings = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, readings
end
---@param di_addr_start integer
---@param count integer
---@return boolean ok, table readings
local _2_read_discrete_inputs = function (di_addr_start, count)
local tasks = {}
local readings = {}
local access_fault = false
local discrete_inputs, _, _, _ = self.rtu.io_count()
local return_ok = ((di_addr_start + count) <= discrete_inputs) and (count > 0)
if return_ok then
for i = 1, count do
local addr = di_addr_start + i - 1
if self.use_parallel then
insert(tasks, function ()
local reading, fault = self.rtu.read_di(addr)
if fault then access_fault = true else readings[i] = reading end
end)
else
readings[i], access_fault = self.rtu.read_di(addr)
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
end
-- run parallel tasks if configured
if self.use_parallel then
parallel.waitForAll(table.unpack(tasks))
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
end
else
readings = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, readings
end
---@param hr_addr_start integer
---@param count integer
---@return boolean ok, table readings
local _3_read_multiple_holding_registers = function (hr_addr_start, count)
local tasks = {}
local readings = {}
local access_fault = false
local _, _, _, hold_regs = self.rtu.io_count()
local return_ok = ((hr_addr_start + count) <= hold_regs) and (count > 0)
if return_ok then
for i = 1, count do
local addr = hr_addr_start + i - 1
if self.use_parallel then
insert(tasks, function ()
local reading, fault = self.rtu.read_holding_reg(addr)
if fault then access_fault = true else readings[i] = reading end
end)
else
readings[i], access_fault = self.rtu.read_holding_reg(addr)
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
end
-- run parallel tasks if configured
if self.use_parallel then
parallel.waitForAll(table.unpack(tasks))
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
end
else
readings = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, readings
end
---@param ir_addr_start integer
---@param count integer
---@return boolean ok, table readings
local _4_read_input_registers = function (ir_addr_start, count)
local tasks = {}
local readings = {}
local access_fault = false
local _, _, input_regs, _ = self.rtu.io_count()
local return_ok = ((ir_addr_start + count) <= input_regs) and (count > 0)
if return_ok then
for i = 1, count do
local addr = ir_addr_start + i - 1
if self.use_parallel then
insert(tasks, function ()
local reading, fault = self.rtu.read_input_reg(addr)
if fault then access_fault = true else readings[i] = reading end
end)
else
readings[i], access_fault = self.rtu.read_input_reg(addr)
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
end
-- run parallel tasks if configured
if self.use_parallel then
parallel.waitForAll(table.unpack(tasks))
if access_fault then
return_ok = false
readings = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
end
else
readings = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, readings
end
---@param c_addr integer
---@param value any
---@return boolean ok, MODBUS_EXCODE|nil
local _5_write_single_coil = function (c_addr, value)
local response = nil
local _, coils, _, _ = self.rtu.io_count()
local return_ok = c_addr <= coils
if return_ok then
local access_fault = self.rtu.write_coil(c_addr, value)
if access_fault then
return_ok = false
response = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
else
response = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, response
end
---@param hr_addr integer
---@param value any
---@return boolean ok, MODBUS_EXCODE|nil
local _6_write_single_holding_register = function (hr_addr, value)
local response = nil
local _, _, _, hold_regs = self.rtu.io_count()
local return_ok = hr_addr <= hold_regs
if return_ok then
local access_fault = self.rtu.write_holding_reg(hr_addr, value)
if access_fault then
return_ok = false
response = MODBUS_EXCODE.SERVER_DEVICE_FAIL
end
else
response = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, response
end
---@param c_addr_start integer
---@param values any
---@return boolean ok, MODBUS_EXCODE|nil
local _15_write_multiple_coils = function (c_addr_start, values)
local response = nil
local _, coils, _, _ = self.rtu.io_count()
local count = #values
local return_ok = ((c_addr_start + count) <= coils) and (count > 0)
if return_ok then
for i = 1, count do
local addr = c_addr_start + i - 1
local access_fault = self.rtu.write_coil(addr, values[i])
if access_fault then
return_ok = false
response = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
else
response = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, response
end
---@param hr_addr_start integer
---@param values any
---@return boolean ok, MODBUS_EXCODE|nil
local _16_write_multiple_holding_registers = function (hr_addr_start, values)
local response = nil
local _, _, _, hold_regs = self.rtu.io_count()
local count = #values
local return_ok = ((hr_addr_start + count) <= hold_regs) and (count > 0)
if return_ok then
for i = 1, count do
local addr = hr_addr_start + i - 1
local access_fault = self.rtu.write_coil(addr, values[i])
if access_fault then
return_ok = false
response = MODBUS_EXCODE.SERVER_DEVICE_FAIL
break
end
end
else
response = MODBUS_EXCODE.ILLEGAL_DATA_ADDR
end
return return_ok, response
end
-- validate a request without actually executing it
---@param packet modbus_frame
---@return boolean return_code, modbus_packet reply
public.check_request = function (packet)
local return_code = true
local response = { MODBUS_EXCODE.ACKNOWLEDGE }
if #packet.data == 2 then
-- handle by function code
if packet.func_code == MODBUS_FCODE.READ_COILS then
elseif packet.func_code == MODBUS_FCODE.READ_DISCRETE_INPUTS then
elseif packet.func_code == MODBUS_FCODE.READ_MUL_HOLD_REGS then
elseif packet.func_code == MODBUS_FCODE.READ_INPUT_REGISTERS then
elseif packet.func_code == MODBUS_FCODE.WRITE_SINGLE_COIL then
elseif packet.func_code == MODBUS_FCODE.WRITE_SINGLE_HOLD_REG then
elseif packet.func_code == MODBUS_FCODE.WRITE_MUL_COILS then
elseif packet.func_code == MODBUS_FCODE.WRITE_MUL_HOLD_REGS then
else
-- unknown function
return_code = false
response = { MODBUS_EXCODE.ILLEGAL_FUNCTION }
end
else
-- invalid length
return_code = false
response = { MODBUS_EXCODE.NEG_ACKNOWLEDGE }
end
-- default is to echo back
local func_code = packet.func_code
if not return_code then
-- echo back with error flag
func_code = bit.bor(packet.func_code, MODBUS_FCODE.ERROR_FLAG)
end
-- create reply
local reply = comms.modbus_packet()
reply.make(packet.txn_id, packet.unit_id, func_code, response)
return return_code, reply
end
-- handle a MODBUS TCP packet and generate a reply
---@param packet modbus_frame
---@return boolean return_code, modbus_packet reply
public.handle_packet = function (packet)
local return_code = true
local response = nil
if #packet.data == 2 then
-- handle by function code
if packet.func_code == MODBUS_FCODE.READ_COILS then
return_code, response = _1_read_coils(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.READ_DISCRETE_INPUTS then
return_code, response = _2_read_discrete_inputs(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.READ_MUL_HOLD_REGS then
return_code, response = _3_read_multiple_holding_registers(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.READ_INPUT_REGISTERS then
return_code, response = _4_read_input_registers(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.WRITE_SINGLE_COIL then
return_code, response = _5_write_single_coil(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.WRITE_SINGLE_HOLD_REG then
return_code, response = _6_write_single_holding_register(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.WRITE_MUL_COILS then
return_code, response = _15_write_multiple_coils(packet.data[1], packet.data[2])
elseif packet.func_code == MODBUS_FCODE.WRITE_MUL_HOLD_REGS then
return_code, response = _16_write_multiple_holding_registers(packet.data[1], packet.data[2])
else
-- unknown function
return_code = false
response = MODBUS_EXCODE.ILLEGAL_FUNCTION
end
else
-- invalid length
return_code = false
end
-- default is to echo back
local func_code = packet.func_code
if not return_code then
-- echo back with error flag
func_code = bit.bor(packet.func_code, MODBUS_FCODE.ERROR_FLAG)
if type(response) == "nil" then
response = { }
elseif type(response) == "number" then
response = { response }
elseif type(response) == "table" then
response = response
end
end
-- create reply
local reply = comms.modbus_packet()
reply.make(packet.txn_id, packet.unit_id, func_code, response)
return return_code, reply
end
-- return a SERVER_DEVICE_BUSY error reply
---@return modbus_packet reply
public.reply__srv_device_busy = function (packet)
-- reply back with error flag and exception code
local reply = comms.modbus_packet()
local fcode = bit.bor(packet.func_code, MODBUS_FCODE.ERROR_FLAG)
local data = { MODBUS_EXCODE.SERVER_DEVICE_BUSY }
reply.make(packet.txn_id, packet.unit_id, fcode, data)
return reply
end
-- return a NEG_ACKNOWLEDGE error reply
---@return modbus_packet reply
public.reply__neg_ack = function (packet)
-- reply back with error flag and exception code
local reply = comms.modbus_packet()
local fcode = bit.bor(packet.func_code, MODBUS_FCODE.ERROR_FLAG)
local data = { MODBUS_EXCODE.NEG_ACKNOWLEDGE }
reply.make(packet.txn_id, packet.unit_id, fcode, data)
return reply
end
-- return a GATEWAY_PATH_UNAVAILABLE error reply
---@return modbus_packet reply
public.reply__gw_unavailable = function (packet)
-- reply back with error flag and exception code
local reply = comms.modbus_packet()
local fcode = bit.bor(packet.func_code, MODBUS_FCODE.ERROR_FLAG)
local data = { MODBUS_EXCODE.GATEWAY_PATH_UNAVAILABLE }
reply.make(packet.txn_id, packet.unit_id, fcode, data)
return reply
end
return public
end
return modbus