National Instruments  777405-01 Digital I/O Device

Part Number 777405-01 is the identifying part number for the National Instruments DAQPad-6507 Digital I/O Device. The 777405-01 consists of 96 TTL-compatible digital I/O lines where the absolute max voltage rating lies between -0.5 V to +5.5 V with respect to the ground. During power on, the channels are configured as inputs in the HIGH state. Data transfers can take place through interrupts or programmed I/O. As for the digital logic levels, the input low voltage ranges between -0.3 V and 0.8 V whereas the input high voltage lies between 2.2V and 5.3 V. The maximum input low current and input high current are -1.0 µA and 1.0 µA respectively.

On the other hand, the output low voltage ranges between 0 V and 0.4 V whereas the output high voltage is between 3.7 V and 5.0 V. When connected to an external power supply (9 VDC to 30 VDC), the power requirement of the module is 12 W (max). However, when it is connected to a USB supply (4.4 VDC to 5.25 VDC), the power requirement is 220 mA typical; 500 mA maximum. The operation of the 777405-01 is governed by a few key components. Four 82C55A programmable peripheral interfaces act as the heart of the module and each of those contains 24 programmable I/O pins representing three 8-bit ports. Likewise, the programmable interface has three modes of operation: simple I/O, strobed I/O, and bidirectional I/O. Similarly, the interrupt control circuitry enables and disables interrupts. Furthermore, there is a USB microcontroller that consists of a circuitry responsible for transmitting and receiving data over the USB using NI-DAQ. 

The 777405-01 measures (9.0 by 5.7 in.) in physical dimensions. The recommended temperature range for the operation of the 777405-01 is 0 °C to 70 °C at a relative humidity of up to 5% to 90% RH. On the other hand, it can be stored at a wider range of –55° to 150° C.