Ticket #3: What is the difference between a Template definition and instance? discussion

Page 1.0 of 1.16

  • aliazzz

    aliazzz - 2020-04-26
    • Description has changed:

    Diff:

    --- old
+++ new
@@ -1,31 +1,30 @@
 Q: What is the difference between a Template definition and instance?

 A: There are two parts to a Template
-    * **Template Definition**
+    *Template Definition*
     This metric will will contain all the member Metrics with their default values/properties,
     as well as any Parameters with their default values. This metric is always only published
     in the NBIRTH message

-    * **Template Instance**
+    *Template Instance*
     This metric is one or more "instances" of the above definition. It will contain the any
     member metrics with values/properties that are overridden/different from the defaults in
     the Template Definition. They are published as you would normal tags (BIRTH/DAT/CMD). 
     When published in a NDATA/DDATA/NCMD/DCMD message they may only contain a
     subset of the member Metrics (if those are the only values that have changed)

-    * **Other template fields**
-            *isdefinition*
+    * Other template fields*
+            isdefinition
                 True for a Template Definition metric, False for a Template Instance Metric
-            *templateref*
+            templateref
                 This is used by a Template Instance to specify the "name" of the Template Definition
-            *ishistorical*
+            ishistorical
                 Used to mark a Template Instance (or any Metric) as a historical (rather than a live) 
                 value. MQTT Engine may handle historical Metrics differently depending on how it
                 is configured (see MQTT Engine documentation)
-            *istransient*
+            istransient
                 Not currently used, will be ignored by MQTT Engine, can be omitted or set to false
-
-            *version *
+            version
                 Not currently used, will be ignored by MQTT Engine, can be omitted or set to null
    • status: --> open
     

  • aliazzz

    aliazzz - 2020-04-26
    • Attachments has changed:

    Diff:

    --- old
+++ new
@@ -1 +0,0 @@
-template_samples.txt (2.6 kB; text/plain)
     

  • aliazzz

    aliazzz - 2020-04-26
    • Description has changed:

    Diff:

    --- old
+++ new
@@ -1,19 +1,19 @@
 Q: What is the difference between a Template definition and instance?

 A: There are two parts to a Template
-    *Template Definition*
+    Template Definition
     This metric will will contain all the member Metrics with their default values/properties,
     as well as any Parameters with their default values. This metric is always only published
     in the NBIRTH message

-    *Template Instance*
+    Template Instance
     This metric is one or more "instances" of the above definition. It will contain the any
     member metrics with values/properties that are overridden/different from the defaults in
     the Template Definition. They are published as you would normal tags (BIRTH/DAT/CMD). 
     When published in a NDATA/DDATA/NCMD/DCMD message they may only contain a
     subset of the member Metrics (if those are the only values that have changed)

-    * Other template fields*
+    Other template fields
             isdefinition
                 True for a Template Definition metric, False for a Template Instance Metric
             templateref
@@ -27,180 +27,4 @@
             version
                 Not currently used, will be ignored by MQTT Engine, can be omitted or set to null

-
-This template_samples.txt (see also the attachment) contains some sample template structures (in JSON) as well as some Java code for creating a Template. These should help show the basic Template structure and contain the important fields of a Template Definition and Instance. However, they are just references expressed in JSON, not actual protobuf representations (which may be a bit more verbose)
-
-~~~
-{
-"name": 
-"TemplateDef",
-"timestamp": 
-1499817463261,
-"dataType": 
-"Template",
-"value": 
-{
-"version": 
-"v1.0",
-"isDefinition": 
-true,
-"metrics": 
-[
-{
-"name": 
-"floatMember",
-"timestamp": 
-1499817463260,
-"dataType": 
-"Float",
-"value": 
-1.23
-},
-{
-"name": 
-"stringMember",
-"timestamp": 
-1499817463260,
-"dataType": 
-"String",
-"value": 
-"123"
-}
-],
-"parameters": 
-[
-{
-"name": 
-"Param1",
-"type": 
-"Boolean",
-"value": 
-true
-},
-{
-"name": 
-"Param2",
-"type": 
-"Int32",
-"value": 
-123
-}
-]
-}
-}
-{
-"name": 
-"TemplateInst",
-"timestamp": 
-1499817757169,
-"dataType": 
-"Template",
-"value": 
-{
-"reference": 
-"TemplateDef",
-"isDefinition": 
-false,
-"metrics": 
-[
-{
-"name": 
-"floatMember",
-"timestamp": 
-1499817757169,
-"dataType": 
-"Float",
-"value": 
-3.21
-},
-{
-"name": 
-"stringMember",
-"timestamp": 
-1499817757169,
-"dataType": 
-"String",
-"value": 
-"321"
-}
-],
-"parameters": 
-[
-{
-"name": 
-"Param1",
-"type": 
-"Boolean",
-"value": 
-false
-},
-{
-"name": 
-"Param2",
-"type": 
-"Int32",
-"value": 
-321
-}
-]
-}
-}
-Template 
-templateDef 
-=    new 
-TemplateBuilder()
-.version("v1.0")
-.definition(true)
-.addParameter(new 
-Parameter("Param1", 
-ParameterDataType.Boolean, 
-true))
-.addParameter(new 
-Parameter("Param2", 
-ParameterDataType.Int32, 
-(int)123))
-.addMetric(new 
-MetricBuilder("floatMember",
-MetricDataType.Float, 
-1.23F).createMetric())
-.addMetric(new 
-MetricBuilder("stringMember", 
-MetricDataType.String, 
-"123").createMetric())
-.createTemplate();
-Metric 
-metric 
-=    new
- MetricBuilder("TemplateDef",
- Template, 
-templateDef).createMetric();
-Template 
-templateInst 
-=    new 
-TemplateBuilder()
-.definition(false)
-.templateRef("TemplateDef")
-.addParameter(new 
-Parameter("Param1", 
-ParameterDataType.Boolean, 
-false))
-.addParameter(new 
-Parameter("Param2", 
-ParameterDataType.Int32, 
-(int)321))
-.addMetric(new 
-MetricBuilder("floatMember",
-MetricDataType.Float, 
-3.21F).createMetric())
-.addMetric(new 
-MetricBuilder("stringMember", 
-MetricDataType.String, 
-"321").createMetric())
-.createTemplate();
-Metric 
-metric 
-=    new
- MetricBuilder("TemplateInst",
- Template, 
-templateInst).createMetric(
-~~~
+This template_samples.txt (see attachment) contains some sample template structures (in JSON) as well as some Java code for creating a Template. These should help show the basic Template structure and contain the important fields of a Template Definition and Instance. However, they are just references expressed in JSON, not actual protobuf representations (which may be a bit more verbose)
    • Attachments has changed:

    Diff:

    --- old
+++ new
@@ -0,0 +1 @@
+template_samples.txt (2.6 kB; text/plain)
     

  • i-campbell

    i-campbell - 2020-04-26

    So in CODESYS land, Template Definition = Struct definition OR FB definition
    Template instance = struct instance or FB instance
    Nice work

     

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