Agilent/Keysight 44425A

The Agilent/Keysight 44425A is a 16-channel isolated digital input/interrupt assembly for the HP 3497A Data Acquisition/Control Unit. It operates in two distinct modes: digital input mode accepts up to 16 digital inputs for monitoring limit switches, position indicators, and digital data buses; interrupt mode monitors up to 8 inputs (bits 0–7) and generates interrupt signals to the controller upon specified system conditions. This dual-mode architecture enables both continuous signal monitoring and event-driven program control, making it suitable for immediate reaction to level changes and transient signals.

Technical Specifications

• Digital Input Channels: Up to 16


• Interrupt Channels: Up to 8 (within the 16-channel set)


• Operating Modes: Digital Input Mode and Interrupt Mode


• System Platform: HP 3497A Data Acquisition/Control Unit

Key Features

• Isolated digital input architecture eliminates common-mode coupling issues in multi-channel sensing applications


• Interrupt-driven operation supports time-critical monitoring without continuous polling


• Configurable input allocation allows partitioning of channels between standard monitoring and interrupt functions


• Digital bus monitoring capability for complex signal validation tasks

Typical Applications

• Industrial automation and machinery status monitoring


• Limit switch and position indicator sensing


• Event-driven system control with pre-programmed responses


• Digital logic prototyping and validation


• Expanding digital input capacity of existing data acquisition systems

Compatibility & Integration The 44425A integrates directly into the HP 3497A mainframe. When paired with an Actuator/Digital Output Assembly (such as Option 110), it forms an independent digital input/output port, enabling bidirectional digital control within test and measurement systems.