The Valve Module - Part 1
The Valve Module
Welcome back.
In the last modules we put a Digital and an Analog instrument into operation. I know that you wanted go live for a “check it out”, so in the last module we took a side trip to implement your IO Map.
Let's get back on track. Our objective it to get an instance of each module up and running so that we can drill down in each of them and see what makes them tick.
In this module, we are going to add a Valve module.
The valve module is a simple control that allows the operator to Open or Close a valve. It is designed to integrate with a Hand-Off-Auto (HOA) station, and has two operating modes: Program Mode and Operator Mode.
The Valve module comes equipped with
- Basic On/Off control,
- Program/Operator Mode interface,
- Position Feedback Monitoring/Configuration with
- Fault detection and Alarming,
- Also included is Interlock management,
- And some minor Maintenance Statistics.
The PLC code is based around the Allen-Bradley D2SD (Digital-2-State-Device) instruction which provides comprehensive control for ON/OFF type devices.
The Ignition modules provide clear and concise interfaces for the Operator to Open and Close the valve, and otherwise manage the device.
Create the Module:
Our process to get a valve module up and running is pretty much the same as with the other modules.
PLC
Import the desired module into the PLC
The module is: CRU_XV_Valve_Routine_FBD.L5X
Use Find/Replace to insert your desired base tag name in place of the default tag name (CRU_Valve).
Do a bit of housekeeping in the PLC, including:
- a. Deletion of the placeholder tags
- b. Placing the routine on scan within the “Main” routine by calling it with the JSR.
Ignition
In Ignition, create a new tag instance of the DataType: CRU_XV_Valve_FC.
Give the tag an appropriate name:
Fill out the parameters to match the PLC:
- A_PLC – is the name of the PLC------------------------------------ Facility_1
- B_Program – is the name of the Program within the PLC:--------- V200
- C_InstrType – is the tag prefix of the device:----------------------- XV
- D_InstrTag – is the tag body of the device:------------------------- 200
This creates your base tag for the OPC Path. Ignition uses this path to access the device module in the PLC.
Check to make sure the tag is operating without errors.
Drag-and-Drop the tag onto the graphic – you should see the Valve Legend Plate appear.
Go to Preview Mode
and click on the Valve Legend Plate.
You will see the Valve Primary Faceplate:
Click on the Config icon to display the Valve Configuration Faceplate:
Enter the Name (XV200), Description (Liquids),
*Of course, these are just for our demo. You will use your assigned details for your real installation*.
Setup the Alarm Fault time.
Check the “Show Interlocks” if you have interlocks to shut down this valve.
If you are sending notifications, setup up the Text fields for Faulted/Opened/Closed.
( We will cover notifications in a later video. )
Position Feedback
The instruction D2SD has two feedback inputs: FBO and FB1.
We have assigned the Valve Closed Position Feedback to FB0, and the Valve Opened Position Feedback to FB1.
The matrix in the lower left corner determines how the feedback is used:
Typically when a valve reaches the closed position, it signals the condition with a “1.”
When the valve reaches the Opened Position, it signals that condition with a “1” as well.
For Closed Position Monitoring:
In the ZSC column of the matrix (this is FB0),
We want to see a 1 when Closed by placing a 1 in the Closed Row.
We want to see a 0 when Opened by placing a 0 in the Opened Row.
For Opened Position Monitoring:
In the ZSO column of the matrix (this is FB1),
We want to see a 0 when Closed by placing a 0 in the Closed Row.
We want to see a 1 when Opened by placing a 1 in the Opened Row.
For Valves without Position Monitoring:
Place zero’s in all four entries of the matrix – this indicates there is no position monitoring.
The graphic colors then mimics the command to the valve, instead of the valve position.
0 comments