The NeuroShell Trader Professional includes indicators that can call external DLLs created (usually) in C, C++, Ibasic Pro, Power Basic, or Delphi. This feature is located in the ‘DLL calls’ category in the Indicator Wizard. This is a very powerful feature, because it means that you can build custom indicators and other functions and use them in the NeuroShell Trader. You can even build a business selling these to NeuroShell Trader users. However, you will need to have a programmer available to help you set up the calls to the DLLs, and the programmer will have to know something about the DLL he/she is trying to call.

There are two types of DLL calls:
1. Calling DLL by value. In this mode, the DLL is called once for each bar. The inputs to the DLL will usually be some current or lagged values, and the output will be associated with that bar on the chart. This mode would be perfect for building a custom indicator in C++.

2. Calling DLL by array. In this mode, the DLL is called only once for the entire chart. Each parameter is an array that is as large as the number of bars loaded in the chart. The output is an array of the same size. This mode is for building some sort of process that needs all the data at once.