KAD/DSI/003/B/00 Curtiss-Wright 24-Channel Input Module with Counters and Time Tagging

The Curtiss-Wright / ACRA Control KAD/DSI/003 24-Channel Input Module with Counters and Time Tagging is used to monitors the status (high/low) of up to 24 D/E discrete channels. The first eight input channels have alternative functions as programmable counters, of which four can be configured as resettable event counters. The remaining 16 channels can be used to trigger time-tagged events.

All 24 discrete signals are sampled simultaneously and can be read as a 24-bit word (16-bit + 8-bit or 12-bit + 12-bit). The KAD/DSI/003 uses 24 separate 14-bit A/Ds operating continuously at 111ksps to sample each input so the threshold and hysteresis can be programmed separately for each channel.

The first eight counters (channels 0 to 7) can be programmed as PERIOD, FREQUENCY, EVENTS_SINCE_LAST_READ, EVENTS or ELAPSED time. The range of each counter is programmable as is the threshold, hysteresis sensitivity to the rising/falling edge, and roll-over. If the counter uses more than 16 bits, they are treated as two words.

The remaining 16 channels (8 to 23) control the time tagging to the 8K FIFO. For each input, time tagging can be triggered by a rising and/or falling edge, or neither (when the channel is disabled). Every time a trigger occurs, a 64-bit word is written to the FIFO consisting of the status of the 16 inputs (after the change) and the Binary Coded Decimal (BCD) time of when the event happened (up to 23 hours 59 minutes 59.99 9999 seconds).