Using AdvancedHMI’s PLC drivers with C#

AdvancedHmi is a free and “almost open-source” HMI framework written in VB.Net that offer some drivers for PLCs, and also offer free SCADA objects for winforms users.
I say “almost open-source” because the code of the two main libraries is not provided (MfgControl.AdvancedHMI.Drivers.dll and MfgControl.AdvancedHMI.Controls.dll), but it’s provided how to use them.
What is really good about AdvancedHMI is the easy interface that the drivers offers, that doesn’t change when you change the driver, so you can make the same HMI and using different drivers without much problems.

The drivers

AdvancedHMI contains those drivers:

• Rockwell Automation (Allen Bradley) Controllogix and CompactLogix ethernet/IP driver
• Allen Bradley SLC, MicroLogix, PLC 5 serial and ethernet driver
• OPC Client
• Modbus TCP
• GE Fanuc SNP-X serial port driver
• Siemens PPI driver

Every driver implement this interface:

public interface IComComponent
{
	public delegate void ReturnValues(string[] values);
	int Subscribe(string plcAddress, Int16 numberOfElements, int pollRate, ReturnValues callback);
	int Unsubscribe(int id);
	string ReadAny(string startAddress);
	string[] ReadAny(string startAddress, int numberOfElements);
	string WriteData(string startAddress, string dataToWrite);
	bool DisableSubscriptions { get; set; }
}

and we need those methods:

	string ReadAny(string startAddress);
	string[] ReadAny(string startAddress, int numberOfElements);
	string WriteData(string startAddress, string dataToWrite);

As you can see we can read from an address with the ReadAny method getting PLC values as strings or array of strings, then we can convert them to bool, int, float and so on using the Convert class.
To write is even simpler because you just have to call the method WriteData, providing the address and the value.

Import the library

To create a driver we just need to import the project as reference (or build the dll and import as reference).

Create a driver object

To create a driver object you have to choose the driver. For example let’s say that i want to communicate with a Micrologix1400 via Ethernet/IP.
So i create my plc object in this way:

//at the beginning you must declare
using AdvancedHMIDrivers;

[...namespace and class declaration and so on ...]

//create the object
EthernetIPforSLCMicroComm MyMicroLogix = new EthernetIPforSLCMicroComm();

public MainWindow()
{
     InitializeComponent();

     //assign IP
     MyMicroLogix.IPAddress = "192.168.0.5";
}

Read and Write

Then it is needed to create a timer to read and write.
For this example i use WPF’s DispatcherTimer, but you can use what you prefere.

DispatcherTimer timerReadPLC = new DispatcherTimer();

public MainWindow()
{
     InitializeComponent();

     //assign IP
     MyMicroLogix.IPAddress = "192.168.0.5";

     timerReadPLC.Interval = TimeSpan.FromMilliseconds(200); //every 200ms update
     timerReadPLC.Tick += new EventHandler(timerReadPLC_Tick);
     timerReadPLC.Start();
}

//timer callback
void timerReadPLC_Tick(object sender, EventArgs e)
{
    label1.Content = MyMicroLogix.ReadAny("B3:0/1"); //bool
    label2.Content = MyMicroLogix.ReadAny("N7:0");   //int
    label3.Content = MyMicroLogix.ReadAny("F8:0");   //float
}

To write i use callbacks:

private void button1_Click(object sender, RoutedEventArgs e)
{
    MyMicroLogix.WriteData("N7:0", 1);
}

Where my User Interface is like this:

Documentation

If you browse the solution you will find many documents that explains how to use drivers and how to setup simple examples of applications.

Download the sample

You can download the sample application at this link.
The sample application is provided with all the dlls that you need to make it work, anyway you should download the newest version of AdvancedHmi, compile it and get the newest dlls if you intend to use it separately from your project. Remember that the project MUST be open-source (because of GPL license, check the next paragraph for explanation).

Pro and cons of using AdvancedHMI

PRO

• Quick results: with little code you are able to read and write from a PLC without much problems, so if you are approaching to SCADA with .Net, AdvancedHMI should be your 1st step for communicating with PLC.
• License is fair: About the GPL license, you must give the source code of your application on demand. In short words, it’s a “derivative work” license, so if you use a GPLed library to write a program (AvancedHmi), the “customer” must be able to recompile it if he need to.
  This means that you can integrate your own dlls to protect your know-how, but you can’t keep the program closed source (dlls closed-source are ok if they don’t use the GPL library, the main project must be open). This is common to every other HMI and SCADA on the market by the way.
• Support: AdvancedHMI support is at payment, but they offer training, customization and also a development service. It’s a good point that an open source project offer a support service, because it means that you will not be abandoned if you will encounter problems.
  If you don’t want to pay you have to wait for the next version for bug fixing. But they will fix the bug, for free.

CONS:

• drivers are closed source: if there is a bug (and it happened to me) you need to wait for the new version (check the support forum on sourceforge to have an idea).
• Some drivers are in “alpha stage”: for example the OPC Client that instead of subscribing is adding and removing items at every read (at least in 3.21b).

I reccomend AdvancedHMI

I really reccomend AdvancedHMI for starters in communication with PLCs, so you can setup your application quick and without spending too much time on the PLC communication.
Advanced users (and for advanced i mean peoples that can write protocols, reverse engineering and so on) should check open source libraries, but anyway the advanced user is not the target of AdvancedHMI, despite his name :). AdvancedHMI should be used to get quick result and to develop cheap (0$) and good looking HMI in short time.
You can download AdvancedHMI and the drivers on the sourceforge site.
The programmers of AdvancedHMI also host a website where you can get information and also a youtube channel with a lot of tutorials.