It Is not practical to connect each controllable function of a WDXRF (Wavelength Dispersive X-Ray Fluorescence) spectrometer separately to the laboratory computer. Therefore, a spectrometer controller is used to interface with the hardware control actuators which operate the selectable or settable components of the spectrometer system. The basic function of a controller is to receive sequences of orders from the computer and transmit the data which has been collected. More advanced controllers, such as the one used in the Siemens SRS-300 spectrometer, may perform many additional functions. In addition to handling spectrometer-to-lab computer communication, the SMP (Siemens Microprocessor controller) is capable of monitoring the state of the instrument, resolving conflicts in external or internal requests for action, and terminating spectrometer action which can be seen as hazardous or damaging to the instrument.