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Tag Configuration |
Use the following syntax to configure Tags in E3 or Elipse Power:
•Device: Not used
•Item: This field must use the following syntax
<Topic>[;<Template>[;<Param>]]
Or
<Topic>[(Deadband:<Absolute Deadband>)][(Deadband:<Relative Deadband>%)]
Where:
•<Topic>: Address of an item or topic on a client's database. According to MQTT standard, each item on a client's database can correspond to a free data set, transmitted in Text format. Topics can be organized in a tree, and in this case users must use a slash mark to separate levels. Example:
"station12/pump01/pressure1"
"station12/pump01/pressure2"
A client can also use a number sign (#) and a plus sign (+) to address topics. In the first case, it must be added to a response's request all items containing in its name the current item or its children. For example, for a value "station12#", the following values are returned:
"station12/pump01"
"station12/pump01/pressure1"
"station12/pump01/pressure2"
"station12/pump02"
"station12/pump02/pressure1"
"station12/pump02/pressure2"
In the second case, it must be added to a response's request all items on the same level. For example, for a value "station12/pump01/+", the following values are returned:
"station12/pump01/pressure1"
"station12/pump01/pressure2"
•<Template>: Informs the name of a Template used as a model to interpret data from a message, with the purpose of mapping fields in a message for Tags (timestamp, quality, and values). This Template must be registered on the Templates tab
•<Param>: Informs the name of one of the Template's parameters, in case this Tag must receive only one of the parameters
•<Absolute Deadband>: Absolute value of dead band, applied when writing numerical values
•<Relative Deadband>: Relative value of dead band, applied when writing numerical values
The next table contains examples of message addressing.
Examples of message addressing
Item |
Description |
|---|---|
"station12/pump01" |
In this case the message read or written for the item is a Text-type Tag (String) without any processing |
"station12/pump01;pumpdata" |
Applies a pumpdata Template to the content of station12/pump01. If that Template describes more than one value, users must use a Block Tag in which each Block Element is a value from a Template |
"station12/pump01;pumpdata;V1" |
Same case as the previous one, but retrieving only the first value of the Template and linking it to a Tag, which does not need to be a Block Tag. In this case the Template must describe value V1. For more information, please check the Template tab on topic Driver's Configuration Parameters |
"station12/pump01(Deadband:0.5)" |
If the current value of this topic is a number and a new number value is written, then this new value is only published if the difference between those values is equal to or greater than 0.5 |
"station12/pump01(Deadband:5%)" |
If the current value of this topic is a number and a new number value is written, then this new value is only published if the difference between those values is equal to or greater than 5% of the current value |
"station12/pump01(Deadband:0.5)(Deadband:5%)" |
If the current value of this topic is a number and a new number value is written, then this new value is only published if the difference between those values is equal to or greater than 0.5 or equal to or greater than 5% of the current value |
NOTE |
When a dead band is configured directly in a Tag, this Tag must not be associated to a Template. In this case, the dead band configured in the Publish tab of the configuration window is bypassed. |
To overcome an absolute dead band, the following condition must be met:
|(Current Value) - (New Value)| ≥ (Absolute Deadband)
To overcome a relative dead band, the following condition must be met:
|(Current Value) - (New Value)| ≥ |(Current Value)| * (Relative Deadband) / 100%
If a Tag has both absolute and relative dead bands, meeting any of the previous conditions triggers the publication.
If an information appears in more than one message and a Tag must receive values from all those messages, users can specify an array of addresses in JSON format, according to the following syntax.
["Topic1;Template1;Param1","Topic2;Template2;Param2","Topic3;Template3;Param3"]
For example, let's suppose a device sends two types of messages. Message 1 contains values A, B, and C and Message 2 contains values D, E, F, and B again, in this order. If users want a Tag to receive B values coming from both messages, configure the array in the next format.
["device023/msg1;template1;V2","device023/msg2;template2;V4"]
In this case, the second value configured in template1, received in topic device023/msg1, and the fourth value configured in template2, received in topic device023/msg2, are sent to this Tag.
NOTE |
Users can repeat topics, such as two or more Tags using the same topic, but one of the other parameters, template or param, must be different. |
Examples of Tags:
Tag1: "device023/msg1" - OK
Tag2: "device023/msg1;T1" - OK
Tag3: "device023/msg1;T1;V2" - OK
Tag4: "["device023/msg1;T1;V2","device023/msg1;T1;V3"] - Not accepted. The first element repeats Tag3