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PC/104 I/O Card Uses Event-Sense Technology To Eliminate I/O Polling

Aug. 1, 2000

By monitoring both rising and falling edge transitions, latching them, and then signaling the host processor that a change of input status has occurred, this PC/104-compatible 96-line digital I/O module is said to eliminate the need to continuously poll the 96 I/O points. The PCM-UIO96A card employs two universal I/O controller ASICs that support the various I/O and interrupt configurations, with each I/O line programmable for input, output, or output with read-back operation. Supported on 48 of the lines is a feature called event-sense, which enables the controller to monitor each input line and then generate an interrupt whenever an event occurs. Transition polarity is programmable and enabled on a bit-by-bit basis. And each line's transition is latched so that even short-duration pulses will be recognized. Each output channel is latched and is capable of sinking 12 mA, allowing direct control of up to 96 industry-standard opto-isolated signal conditioning modules by a single PCM-UIO96A card. Inputs can source 0.4 mA per channel. The lightweight (7 oz.), 3.6" x 3.8", PC/104-compliant, TTL-compatible card requires a 5V supply, dissipates only 120 mW without loads, and operates over a -40°C to +85°C temperature range. Price: $225.

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