National Instruments 779522-01 C Series Digital Module 

National Instruments part number 779522-01 is an identifying part number for the NI-9422 a C Series Digital Module. This module supports input voltages up to 60 V and features 8 digital input channels that can operate in sinking or sourcing mode. It includes screw terminal front connectors and achieves a maximum update rate of 250 μs. The Measurement Time parameter determines the duration over which multiple readings of the input signal are averaged. When both the Divisor and Measurement Time values are set, the counter switches to Dynamic Averaging mode. In this mode, the counter calculates measurements based on both the Divisor and Measurement Time settings simultaneously, returning the result of whichever calculation completes first. 

The 779522-01 C Series Digital Module offers flexible signal routing capabilities. Users can direct input signals to the counters from any of the module's eight digital input terminals. By configuring counter properties, users can adjust and customize signal routing as needed. The 779522-01 features a low-power sleep mode, although the availability of system-level sleep mode support depends on the chassis where the module is installed. It supports connection to sourcing-output devices, which can drive current or apply voltage to the DI+ or DI– terminals. An example of a sourcing-output device is an open collector PNP transistor.

The 779522-01 digital input channels operate with floating inputs. Each channel includes DI+ and DI– terminals where voltage signals can be connected. The module detects whether the voltage difference between DI+ and DI– exceeds the defined digital logic thresholds. When an external device applies a voltage within the input ON range to the DI terminal, the channel registers as ON. Conversely, if the voltage falls within the input OFF range, the channel registers as OFF. If no device is connected to DI, the channel defaults to OFF.