Logic functions and central statuses #
The following script applies a calculation function to the given objects with a common tag.
groups
variable is a Lua table where each element is a Lua table with 3 keys:
tag
- input object tagoutput
- output object (must not belong to the same tag)mode
- calculate function
Available calculation functions:
and
- logical AND function (output istrue
when all inputs aretrue
)or
- logical OR function (output istrue
when at least one input istrue
)avg
- average value, boolean values are treated as a number 100 whentrue
sum
- sum of all numeric valuesmax
- maximum valuemin
- minimum value
Additional functions can be added as needed.
updatedelay
variable set the delay before the output value is sent and
the last telegram received for the given group
Create a resident script (sleep time set 0) with the following code:
if not client then
-- each group has 3 fields:
-- tag - status object tag
-- output - status output object
-- mode - calculate mode (and/or/avg)
groups = {
--samples
{ tag = 'my_group_and', output = '4/0/0', mode = 'and' },
{ tag = 'my_group_or', output = '4/0/1', mode = 'or' },
{ tag = 'my_group_avg', output = '4/0/2', mode = 'avg' },
}
-- time to wait between last telegram from any status in group and update
updatedelay = 0.5
timeout = updatedelay / 2
-- object value cache
values = {}
-- object datatype cache
datatypes = {}
-- send update only when value changes
grp.checkupdate = function(alias, value)
if values[ alias ] ~= value then
grp.update(alias, value)
end
end
calc = {}
-- AVERAGE value
calc['avg'] = function(group)
local result, count, value = 0, 0
for _, address in ipairs(group.objects) do
value = values[ address ]
-- number must be in [0..100] range
if type(value) == 'number' then
result = result + value
count = count + 1
-- boolean true is 100%, false is 0%
elseif type(value) == 'boolean' then
if toboolean(value) then
result = result + 100
end
count = count + 1
end
end
if count > 0 then
result = math.floor(result / count + 0.5)
grp.checkupdate(group.output, result)
end
end
-- AND gate
calc['and'] = function(group)
local result = true
for _, address in ipairs(group.objects) do
result = result and toboolean(values[ address ])
end
grp.checkupdate(group.output, result)
end
-- OR gate
calc['or'] = function(group)
local result = false
for _, address in ipairs(group.objects) do
result = result or toboolean(values[ address ])
end
grp.checkupdate(group.output, result)
end
-- MAX value
calc['max'] = function(group)
local result = -math.huge
for _, address in ipairs(group.objects) do
local value = values[ address ]
if type(value) == 'number' then
result = math.max(result, value)
end
end
grp.checkupdate(group.output, result)
end
-- MIN value
calc['min'] = function(group)
local result = math.huge
for _, address in ipairs(group.objects) do
local value = values[ address ]
if type(value) == 'number' then
result = math.min(result, value)
end
end
grp.checkupdate(group.output, result)
end
-- SUM value
calc['sum'] = function(group)
local result = 0
for _, address in ipairs(group.objects) do
local value = values[ address ]
if type(value) == 'number' then
result = result + value
end
end
grp.checkupdate(group.output, result)
end
-- prepare each group
for _, group in ipairs(groups) do
object = grp.find(group.output)
-- cache output status object value and datatype
values[ object.address ] = object.data
datatypes[ object.address ] = object.datatype
group.output = object.address
-- group input status object list
group.objects = {}
-- find all status objects and cache values and datatypes
objects = grp.tag(group.tag)
for _, object in ipairs(objects) do
values[ object.address ] = object.data
datatypes[ object.address ] = object.datatype
table.insert(group.objects, object.address)
end
-- force update on first run
group.timer = 0
-- calc function reference
group.fn = calc[ group.mode ]
end
-- handle group writes
function eventhandler(event)
local dst, datatype
dst = event.dst
datatype = datatypes[ event.dst ]
-- unknown object, stop
if not datatype then
return
end
values[ dst ] = dpt.decode(event.datahex, datatype)
-- check if any group needs to be updated
for _, group in ipairs(groups) do
for _, address in ipairs(group.objects) do
if address == dst then
group.timer = updatedelay
end
end
end
end
require('genohm-scada.eibdgm')
client = eibdgm:new({ timeout = 0.1 })
client:sethandler('groupwrite', eventhandler)
end
delta = 0
repeat
tsec, tusec = os.microtime()
client:step()
tdelta = os.udifftime(tsec, tusec)
-- clock jump
if tdelta < 0 then
delta = timeout
else
delta = delta + tdelta
end
until delta >= timeout
-- check if any group has an active timer
for _, group in ipairs(groups) do
timer = group.timer
if timer then
timer = timer - delta
-- timer expired, run calc function
if timer <= 0 then
group.fn(group)
timer = nil
end
group.timer = timer
end
end
Further assistance can be found in this forum thread