TCP/ip connect and maintain connection

[Azar]

Just add a if condition like this:

Code:

12345

if previousvalue ~= value then   -- send command   sock:send (command)   previousvalue == value end

But if the value is not change often i would make it event based, initiate the connection, write the command and close the connection..

I've decided to go to an event script but cant get this to work.
Event script by Keyword: Symetrix.
all GA's with keyword "Symetrix" also have there control comand number assigned to them by keyword " SYM=### " I'm trying to get the script to insert the control number into the "CS" Command Send line .
I'm getting a log of

 * string: Error: sym=address tag missing

Code:

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182

    local value = event.getvalue()     local dest = event.dst     local grps = GetCBusByKW('Symtrix', 'or')     local k, v, alias, net, app, group     local addr = ''     local buffer = {} log(grps)     for k, v in pairs(grps) do       alias = table.concat(v.address, '/')       if alias == dest then         local tags = v.keywords      --log(tags)         local t         for _, t in ipairs(tags) do           local tp = string.split(t, '=')           tp[1] = trim(tp[1])           if tp[2] then             tp[2] = trim(tp[2])             if tp[1] == 'sym' then               addr = tp[2] -- Get device address               break             end           end         end         break       end     end     if addr ~= '' then       -- create tcp socket       local sock = require('socket').tcp()       sock:settimeout(1)       local connected, err = sock:connect('192.168.1.246', 48631)       -- connect ok       if connected then         alert('[tcp-sock] connection ok')       -- error while connecting       else         log('[tcp-sock] connection failed: '..err)         sock:close()         do return end       end       local command = 'CS '..addr..' '..(value * 257).. '\r'       -- send command       sock:send (command)       local sent = socket.gettime()       local timeout = 5       while true do         char, err = sock:receive(1)         -- error while receiving, timeout or closed socket         if err then           -- remote server closed connection           log('[tcp-sock] connection closed'..err)           break         -- end of line, parse buffer         elseif char == '\r' then           local data = table.concat(buffer)           log(data)           break         -- other char, add to buffer         else           buffer[ #buffer + 1 ] = char         end         if socket.gettime() - sent > 5 then           log('Timeout receiving data')           break         end       end       sock:close()     else       log('Error: sym=address tag missing')     end