National Instruments 779351-01 C Series Digital Module

The National Instruments 779351-01 is an identifying number for the NI-9401 model, and it is designed as a versatile 8-channel bidirectional digital I/O interface. With its great degree of adjustable options, this module can be used with three different configurations: eight digital inputs, eight digital outputs, or four digital inputs and four digital outputs. Because it can be programmed using the LabVIEW FPGA Module, it can be configured in a variety of ways. This includes using reconfigurable I/O (RIO) technology, especially in CompactRIO systems, to create custom high-speed counter/timers, digital communication protocols, and pulse generation.

Connectivity for the eight digital input/output channels is provided by a 25-pin DSUB connector found on the 779351-01. In order to reference an external signal, each one of the nine COM lines can be used using the matching DIO pin on each of these channels, which is internally addressed to COM. Two ports, one holding channels 0 through 3, and the other holding channels 4 through 7, comprise the grouping of the channels. Although all four channels in a port must share the same direction, software setup enables independent direction adjustment for each port.

In terms of protection, each channel of the 779351-01 includes a pull-down resistor and safeguards against overvoltage, overcurrent, and short-circuit conditions. The module's overcurrent safety makes sure that only a predetermined amount of current can be used to source or switch the output load. The power supply voltage of the module will decrease if an overcurrent status develops until the problem is fixed or the module shuts down. In these stages, the module can still receive new configurations and output state data, but it is unable to provide the software with valid input data.

The input/output characteristics of the 779351-01 are defined by its TTL, single-ended type. For input, it handles a maximum voltage of 5.25 V, with high logic levels starting at 2 V and low logic levels maxing out at 0.8 V. For output, it can source up to 5.25 V, with minimum high logic levels of 4.7 V at 100 μA and 4.3 V at 2 mA.