Hello and welcome to a new guide on how to best use Movicon.NExT™.
This technote introduces you to the Engineering Unit concept with the
aim to help you understand how to use this item to scale values deriving
from field devices in Movicon.NExT.
Engineering Units
Engineering Units are normalizations applied to Tags used in Movicon.NExT
to obtain scaled values.
A tag that obtains a value from a field device by means of a communication
driver will be scaled using an engineering unit according to the Raw
Range settings, being the device range, and the Scaled Range settings,
being the value range in the project's I/O Data Server.
Let's analyze this to get a better idea by using a demo project.
Example
We shall create an engineering unit named Div10 which will scale
a value deriving from a field device with a 0-1000 range to a 0-100
range within the I/O Data Server according to the TagValue = DeviceValue/10
formula.
Creating the Engineering Unit
After opening the project within the Movicon.NExT editor, you should:
Open the I/O Data Server
by double-clicking the I/O Data Server located in the application's
tree structure within the Project Explorer panel.
Select
the Engineering Unit tab through which we will create the new
engineering units for the project.
Right
click on the workspace and select the Add Engineering Unit option.
Create
the new Engineering Unit by configuring it as follows:
Engineering
Name: Div10
Engineering
Unit Low Value: 0
Engineering
Unit High Value: 100
Low
Raw Input Value: 0
High
Raw Input Value: 1000
Save the project by clicking the Save All icon on the editor's toolbar.
Inserting and configuring the Modbus TCP-IP driver
Insert a driver in the project. Since we have Modbus TCP ModRS_Sim
simulator at our disposition, add the Modbus TCP-IP driver in this
way by also making sure to have already opened the I/O Data Server:
Select
the Drivers tab needed to add the Modbus TCP-IP driver.
Open
the Drivers tab, right click on the workspace and select Add New
Driver from the menu that appears.
Search
and select the Modbus TCP-IP driver from the list that appears.
Then click on the arrow at the bottom on the far right to continue.
Leave
all the default settings as they are in the configuration page
of the Driver's General Settings and click the arrow at the bottom
again to go to the next step.
Enter
the IP address of your PLC in the Driver's Channel configuration
page. In this example, we will use the local loopback address,
which is 127.0.01. Leave the other properties set for default
and continue on.
In
the Driver's Station configuration page, leave the default settings
as they are and continue by clicking the arrow.
Once
terminated, click Finish to conclude and enter the Driver on the
Driver List.
Creating tags
Once you have created the engineering unit and configured the driver,
select the I/O Data Server's Tag List tab to create a normal tag and
one with an engineering unit.
Open the Tag List and create two new tags:
Right
click on the workspace and select the Add New Tag option from
the menu which opens.
Configure
one of the tags that have just been created as follows:
Name:
MbtcpTag
Model
Type: Variable
Data
Type: Int16
Configure
the other one as follows:
Name:
MbtcpTagEU
Model
Type: Variable with Engineering Unit
Engineering
Unit: Div10
Data
Type: Int16
Assign
a PLC address to the tags by clicking the three dots between brackets
on the far right of the Modbus TCP-IP and use the 40001 address
by configuring them as follows:
Function
Code: MutlipleRegisters
Start
Address: 0
File
Number: 0
Element
Number: 0
Link
Type: Read/Write
Station:
Station0
Confirm
the configuration by clicking on the OK button.
Save the project by clicking on the Save All icon located on the
editor's toolbar.
Runtime Test
Start ModRS_Sim simulator by double clicking on its icon.
Start the Movicon.NExT project's Server-side only by clicking on the
Start Server button.
Once the Server has started up, click on Tags in the OPC UA Browser
window.
Change the value of the MbtcpTag tag and the value of the MbtcpTagEU
tag will automatically be divided by a factor of 10 according to the
engineering unit configured in the project.