The DB-24SSR/DB-24SSRDC includes 24 normally open, or form A, solid-state relays The board interface to filed logic signals, eliminating ground-loop problems and isolating the host computer from damaging voltages. The user can use the DB-24SSR/DB-24SSRDC to switch high voltage load, up to 240 VAC/50 VDC and up to 4 A. The relay is energized by applying a 5-voltage signal to the appropriate relay channel on the 50-pin header or 37-pin D-sub connector. Twenty-four enunciator LEDs, one for each relay, light when their associated relay is activated. Because there is a D-sub 37-pin connector on the board, the user may use it to interface to any TTL output board. In other words, the user may use it as a general purpose solid state relay output board.