The SEII card in your computer interfaces to your pulse processor and transmits data which allows your EDS application (DTSA or FLAME) to acquire and display an X-ray spectrum. Pulse processors create a rather simple output signal that can be simulated with a pulse generator. This lends itself to a particularly simple way to diagnose the basic operation of the board. The concept is to simulate the acquisition of an X-ray spectrum with a pulse generator. With this simulation, you can prove that the SEII X-ray acquisition functions are performing correctly (or not).

The procedure here is almost identical to that for checking the SEII card by itself. You must read that procedure first, as it contains crucial information not presented here.

Make sure that the ribbon cable from the back of the SEII card (in the computer) to the Scanning Interface Unit (SIU) is connected and seated firmly on both ends. Make sure that the SIU is powered. Disconnect the PHA Logic I/O cable (that goes to the pulse processor) from the back of the SIU. Using your favorite connection scheme (we suggest paper clips), wire the SIU rear-panel PHA Logic I/O connector as follows:

Follow all steps outlined on the page that tests this function for the SEII card by itself.

Critical Note: The SIU box passes the ADC Busy, Fast Channel, and Live Time signals without modifying them; however, the SIU contains a gain and offset circuit for the analog x-ray pulse. It is therefore possible that the single narrow peak that appears in your DTSA spectrum display window will be at a different energy than the location shown previously. Otherwise, the signals will look similar to what you see when you are testing the SEII card by itself.

Given the above caveat, if you see the proper behavior, there is nothing wrong with either the basic EDS operation of the SEII card or the SIU. You must look elsewhere for your problems.