Create an OpenIGTLink connector in the OpenIGTLinkIF module. Find it under the IGT category in the modules list. If you activate the connection, it will automatically generate a transform node in the Slicer scene, and update it any time it receives a new OpenIGTLink message with the same device name.
You may find useful related information in these tutorials: http://www.slicerigt.org/wp/user-tutorial/
Thanks for your help! In my application, there are two EM sensors embedded in a flexible instrument. There is a standalone software in charge of communication with the EM sensors and sent a message containing the two 4x4 matrices derived from two sensors to 3D Slicer (server). I have tried to create an OpenIGTLink connector, and it does work. But it can not be obtained from vtkMRMLLinearTransformNode, because there are two matrices in a message are sent to 3D Slicer. So can you give me some advice how to get this message, or any examples?
No need to develop any module. You can use Plus Server for connecting NDI tracker and broadcast data through OpenIGTLink. OpenIGTLinkIF module in Slicer can connect to Plus Server, receive transforms and update corresponding transforms in the scene in real-time. See SlicerIGT tutorials for step-by-step instructions.