Digital I/O for USB

National Instruments has announced the NI USB-6509, a bus-powered portable USB digital I/O device acquiring data in a broad range of applications.

With 96 bidirectional digital I/O channels and plug-and-play USB connectivity, the device is suitable for industrial control and automated test applications yet versatile enough for general-purpose data acquisition and academic applications.

It delivers to a portable USB form factor, an industrial feature set of four high-reliability features for industrial or harsh applications previously available only in PCI and PXI systems.

The industrial feature set includes programmable power-up states, digital I/O watchdog timers, change detection and programmable input filters. With programmable power-up states, engineers can predefine the state in which the USB-6509 device powers up, ensuring consistent operation when connected to industrial actuators such as pumps, valves, motors or relays.

Digital I/O watchdog timers can detect a variety of fault conditions, such as a computer crash, and automatically respond by setting the outputs to a user-defined safe state. With change detection, the device automatically triggers an application to perform a read operation after a digital line changes state.

Engineers can also eliminate unintended glitches and spikes in input data and avoid false readings caused by noise with programmable input filters.

The 96-channel device is compatible with transistor-transistor logic, complementary metal oxide semiconductor and 5 V digital logic levels, and each port of eight lines is individually configurable for input or output.

The device can drive external digital devices such as solid-state relays with current up to 24 mA per line, while pull-up and pull-down resistors included on the device stabilise the bus potential during a non-access state.

The bus-powered device can source up to 215 mA total across all digital output lines. An optional 12 VDC power supply is available for additional sourcing current.