National Instruments 779787-01 C Series Digital Module

The National Instruments 779787-01 is an identifying part number of the NI-9403, designed as a digital I/O interface with 32 bidirectional channels that provides input and output functions. Each channel has transient isolation between the I/O channels and the backplane and can handle five V/TTL signals. Users can program the module using the LabVIEW FPGA Module thanks to its reconfigurable I/O (RIO) technology, which is proprietary to CompactRIO systems. Because of its adaptability, the 779787-01 can be used for a wide range of tasks, such as pulse generation, digital communication protocols, and bespoke high-speed counter/timers.

The 779787-01 is a software-timed, static digital I/O module that fits inside a CompactDAQ chassis. Unfortunately, because of the serial data transfer, it is unable to allow the routing of timing or triggering signals. The module is designed with characteristics including 60 VDC CAT I isolation, ±30 V overvoltage protection, and up to 2 mA output current per channel. These features guard against harm from electrical malfunctions and guarantee dependable functioning in a variety of scenarios.

Each digital line on the 779787-01 module has a programmable direction for input and output operations. It is in the input power-on state by default. A maximum input current of ±250 µA and an input capacitance of 30 pF are examples of the input parameters. The module provides an output with a channel-to-channel skew of 265 ns and a propagation delay of up to 330 ns. With the cRIO-9151 R Series Expansion chassis, the update/transfer time is 8 µs; for all other chassis, it is 7 µs, with an 18 µs direction change time.

For input signals, the module runs between -0.25 V to 5.25 V in voltage. With a minimum hysteresis (VH) of 0.2 V, it can detect low input signals (VIL) at a maximum of 0.8 V and strong input signals (VIH) at a minimum of 2.2 V. The 779787-01has the capability to produce a minimum 4.75 V high output voltage (VOH) when sourcing 100 µA and 4.4 V high output voltage (VOH) when sourcing 2 mA. At a maximum of 0.1 V while sinking 100 µA and 0.26 V when sinking 2 mA, the low output voltage (VOL) is measured.