Safe Property Values based on Time

[igor1]

Hello Peoples!

I need your help.

I have a thing connected via WebSocket (EdgeMicrosrever) to TWX Server.

This Thing sends every 6 Seconds current Property values via LuaScript.

Now I need two of these Properties to work with.

Weight - Value and Time - Value (Edge Thing Time, not the TWX Server Time)

But since i get every 6 seconds the current value - I dont need all the Values.

Im my case two Values per Property per Day would be enough.

Like --Weight and Timestamp Value-- at 8:00:00 and 18:00:00 Oclock Servertime dayli.

In my mind it looks like...

04.09.2018 08:00:00 40000(gr) 07:59:56

04.09.2018 18:00:00 35892       17:59:56

05.09.2018 08:00:00 34000        07:59:55

05.09.2018 18:00:00  28804      17:59:57

What do I need this data for?

First of All I want to visualize the change graphically, but also get a good overview just by seeing the Values.

Further I want to use this values to make a forecast on how long it will take to weight = 0.

Should i invoke the QueryPropertyHistory Service?

Should I use Valuestream? Datatable?

Should I create a Service?

Do I need to use Analytics?

How do I avoid Spam by collecting every single Value been send every 6 seconds?

Please help me to understand TWX.

Thank You!!

[PaiChung]

if you only need to record two values a day and you can't change the agent.

I would use a DataChange Subscription, evaluate if the point coming in is one you want to keep based on whatever you deem best. and then write them to a Stream

[igor1]

Dear Pai,

I have my "Weight_Stream" Stream based on "Weight_Data" Data Shape with TWXPersistenceProvider.

In my origin Thing I created a DataChange Subscription @ Weight Property. I used the Snippet to Add a Stream Entry.

This is how the subscription looks like now:

// tags:TAGS
var tags = new Array();

// timestamp:DATETIME
var timestamp = new Date();

// values:INFOTABLE(Datashape: Weight_Data)
var values = Things["Weight_Stream"].CreateValues();

values.Weight = undefined; //NUMBER

// location:LOCATION
var location = new Object();
location.latitude = 0;
location.longitude = 0;
location.elevation = 0;
location.units ="WGS84";

var params = {
    timestamp : timestamp,
    source : me.Weight,
    values : values,
    location : location
};

// AddStreamEntry(tags:TAGS, timestamp:DATETIME, source:STRING("me.name"), values:INFOTABLE(Weight_Data), location:LOCATION):NOTHING
Things["Weight_Stream"].AddStreamEntry(params);
_____________________________

Unfortunately my Stream stays empty. What have I done wrong? The one property i need is NUMBER. Do I need to prepare somehow the Data Shape/ Stream?

Thanks a lot in advance

igor