RMCLink Class

This class is used to communicate with RMC controllers both by reading information from the controller and writing data to the controller. Notice that there are no public constructors, and that instead the static CreateEthernetLink and CreateSerialLink methods are used to create RMCLink instances.

Public Static Methods

CreateEthernetLink	Creates an RMCLink object for communicating with a controller (RMC70, RMC150, RMC200, RMC100) over Ethernet.
CreateSerialLink	Creates an RMCLink object for communicating with a controller (RMC70, RMC100) over a serial port.
CreateUSBLink	Creates an RMCLink object for communicating with a controller (RMC70, RMC150, RMC200) over a USB port.
FRegToLReg	Converts to an integer (L) register value from an intermediate form used when reading mixed F and L registers with ReadFFile.
LRegToFReg	Converts an integer (L) register value into an intermediate form used when writing mixed F and L registers with WriteFFile.

Public Instance Methods

CancelRequest	This method can be used in multi-threaded applications to cancel the currently-in-progress read, write, or connect request.
Connect	Establishes a connection with a controller using the settings specified when the RMCLink instance was created (device type, port name, host name).
Disconnect	Closes the connection associated with this instance, if one has been established.
Dispose	Releases the unmanaged resources used by the RMCLink object.
IsConnected	Checks to see if the link is currently connected to a controller.
ReadBit	Reads a single bit from an integer (L) register in the controller.
ReadBitField	Reads a bit field (range of bits) from an integer (L) register in the controller.
ReadFFile	Reads one or more floating-point (F) registers from the controller.
ReadImage	Reads the controller image into an integer array.
ReadImageToFile	Reads the controller image and saves it in a file.
ReadLFile	Reads one or more integer (L) registers from the controller.
WriteFFile	Writes to one or more floating-point (F) registers in the controller.
WriteImage	Writes the controller image from an integer array to the controller, and applies this image in the controller.
WriteImageFromFile	Writes the controller image from a file to the controller, and applies this image in the controller.
WriteLFile	Writes to one or more integer (L) registers in the controller.

Thread Safety

This type is safe for multithreaded operations.

Remarks

An RMCLink object is typically used through the following steps:

Create an RMCLink instance by calling one of the static CreateEthernetLink, CreateSerialLink or CreateUSBLink methods, which specify the types and address (serial port or host name) of the controller you want to connect to. Notice that the new operator is not used for creating RMCLink instances.
Connect to the controller by calling Connect.
Read from and/or write to the controller using any of the following methods: ReadBit, ReadBitField, ReadFFile, ReadLFile, WriteFFile, WriteLFile, ReadImage, ReadImageToFile, WriteImage, WriteImageFromFile. Notice that it is not necessary to disconnect and re-connect after each call.
After you are done communicating with the controller, call the Disconnect method to free up the serial port or close the TCP/IP connection.

Notice that all of these steps need not be done in the same method in your application. Many applications will create an RMCLink instance when the application is started and use that instance for the life of the application.

Error handling

When programming communications, it is always possible for unexpected errors to occur. That is, the program can never predict when the cable may be disconnected or the remote device will be powered off. Therefore, many of RMCLink's methods can fail, particularly Connect, ReadBit, ReadBitField, ReadFFile, ReadLFile, WriteFFile, WriteLFile, ReadImage, ReadImageToFile, WriteImage and WriteImageFromFile. When any of the RMCLink methods fail, they throw .NET exceptions. Each method's help topic lists the exceptions that can be thrown by the method and the circumstances that can cause each exception.

Synchronous (Blocking) Methods

All RMCLink methods are synchronous, which means that they will not return until the requested action is completed or has failed (as noted above, failure will not strictly return, but instead throw an exception). Notice also that most communications methods, particularly the methods relating to reading, writing, and connecting, can take several seconds to complete, particularly if the connection is broken. If this method is called on the main thread, then the application will likely be unresponsive until the method completes. For applications where this is not acceptable, this and other synchronous methods should be called from a worker thread. To further enhance responsiveness, the CancelRequest method can be used to allow the main thread (through a Cancel button or similar) to cancel a communication in the worker thread.

Example

The following code example illustrates the basic use of the RMCLink class:

Visual Basic

Imports RMCLinkNET
 
Module Example
    Sub Main()
        ' Create the object itself.
        Dim rmc As RMCLink = RMCLink.CreateSerialLink(DeviceType.RMC70, "COM1")
 
        ' Connect to the controller.
        rmc.Connect()
 
        ' Read and display Axis 0's Actual Position (F8:8).
        Dim data() As Single = New Single(0) {}
        rmc.ReadFFile(FileNumber70.fn70StatusAxis0,8,data,0,1)
        Console.WriteLine("Axis0 Actual Position = " & data(0) & " inches")
 
        ' Disconnect from the controller.
        rmc.Disconnect()
    End Sub
End Module

using System;
using RMCLinkNET;
 
namespace Example
{
    public class Program
    {
        static void Main()
        {
            // Create the object itself.
            RMCLink rmc = RMCLink.CreateSerialLink(DeviceType.RMC70, "COM1");
 
            // Connect to the controller.
            rmc.Connect();
 
            // Read and display Axis 0's Actual Position.
            float[] data = new float[1];
            rmc.ReadFFile(FileNumber70.fn70StatusAxis0,8,data,0,1);
            Console.WriteLine("Axis0 Actual Position = " + data[0] + " inches");
 
            // Disconnect from the controller.
            rmc.Disconnect();
        }
    }
}

Visual C++/CLI

using namespace System;
using namespace RMCLinkNET;
 
int main()
{
    // Create the object itself.
    RMCLink^ rmc = RMCLink::CreateSerialLink(DeviceType::RMC70, "COM1");
 
    // Connect to the controller.
    rmc->Connect();
 
    // Read and display Axis 0's Actual Position.
    array<float>^ data = gcnew array<float>(1);
    rmc->ReadFFile(FileNumber70::fn70StatusAxis0,8,data,0,1);
    Console::WriteLine("Axis0 Actual Position = " + data[0] + " inches");
 
    // Disconnect from the controller.
    rmc->Disconnect();
 
    return 0;
}

Requirements

Namespace: RMCLinkNET

Assembly: RMCLink.Interop (in RMCLink.Interop.dll)