rrdtool problem

[baggins]

Hi,

For those who might be interested to get these multi-valued graphs in their visualization, this is what I ended up doing:

-mark the objects to be used as 'export'.
-the second step involves another server that runs 24x7, otherwise the graphs will be incomplete... I used a powerful machine that I use for backups, Logitech Media Server, zoneminder, etc. I believe that a simple raspberry should do the trick also.
-create rrd archive (see original post).
-schedule a script that runs every x minutes. My script fetches the data, updates the rrd, creates the graph and moves it to the DocumentRoot of the webserver.

This is the script (note that this is quite a basic script with no error checking etc...

Code:

require('socket.http') socket.http.TIMEOUT = 15 -- get data local LM_data = socket.http.request('http://remote:remote@<ip_of_LM>/scada-remote?m=xml&r=objects') if not LM_data then  log('Data cannot be fetched.')  return end for i in string.gmatch(LM_data, '<object.-</object>') do  if i ~= nil then      address =  i:match([[<address>(.-)</address>]])      data =  i:match([[<data>(.-)</data>]])      if address == '4/1/11' then          T_intake = data      end      if address == '4/1/12' then          T_supply = data      end      if address == '4/1/14' then          T_discharge = data      end      if address == '4/1/13' then          T_exhaust = data      end  end end -- update rrd rrdupdate = "rrdtool update <path_to>/ventilatie.rrd N:" ..T_intake ..":" ..T_supply ..":" ..T_discharge ..":" ..T_exhaust result = os.execute(rrdupdate) --create graph rrdgraph = "rrdtool graph <path_to>/ventilatie.png -a PNG --title='Ventilatie °C' --slope-mode " .. " DEF:T_i=<path_to>/ventilatie.rrd:T_intake:AVERAGE " .. " DEF:T_s=<path_to>/ventilatie.rrd:T_supply:AVERAGE " .. " DEF:T_d=<path_to>/ventilatie.rrd:T_discharge:AVERAGE " .. " DEF:T_e=<path_to>/ventilatie.rrd:T_exhaust:AVERAGE " .. " --width 640" .. " --height 240" .. " --full-size-mode" .. " --color BACK#243d47" .. " --color CANVAS#243d47" .. " --color FRAME#243d47" .. " --color FONT#ffffff" .. " --color AXIS#515d62" .. " --color GRID#515d62" .. " --color MGRID#515d62" .. " --font TITLE:13:Arial" .. " --font AXIS:10:Arial" .. " --font LEGEND:9:Arial" .. " --grid-dash 1:0" .. " --border 0" .. " --y-grid 10:1" .. " LINE1:T_i#ff0000:' Invoer'" .. " LINE1:T_s#0400ff:' Toevoer'" .. " LINE1:T_d#aaff00:' Afvoer'" .. " LINE1:T_e#35b73d:' Uitvoer'" result = os.execute(rrdgraph) -- move graph to web server result = os.execute("sudo mv <path_to>/ventialtie.png /var/www/html/ventilatie")

Attached is the result.