The PCI-RLY is a PCI compatible half-card which provides isolated digital inputs, outputs and counter/timers. There are 16 galvanically isolated, current-limited digital inputs available on the board, which will accept up to 50 volts DC or AC peak, and which switch at a nominal 3.5 volts DC or AC peak. There are 8 normally open reed relay contact outputs, which are isolated from the digital inputs and the host PC. The contacts are isolated and protected by resettable fuses. There are also three programmable counter/timers, the enable and clock inputs being available, isolated externally, if required , and the outputs being accessible isolated, externally and as interrupt sources.
A 4Mhz crystal oscillator is available on board to allow the counter/timers to act as accurate time bases. All Input/Output lines are available at an industry standard 50 way D-type plug connector. One PCI interrupt line may be selectively driven by the five interrupt sources on the board, the interrupting source being readily identified by software interrogation of the on-board registers. The five interrupt sources are the three counter timer outputs and a change of state detector on each byte of the digital inputs.