Keysight / Agilent / HP Z2404A 64-Channel Isolated Digital Input/Interrupt Module

The Keysight Z2404A is a 64-channel isolated digital input/interrupt module for VXIbus systems, delivering high-density signal monitoring and interrupt handling in noise-prone industrial and laboratory environments. Optically isolated inputs withstand up to 125 V rms or Vdc, while jumper-selectable thresholds and programmable debounce accommodate diverse signal conditioning requirements. The module supports four input voltage levels - 5 Vdc, 12 Vdc, 24 Vdc, and 48 Vdc - with configurable minimum thresholds of 1, 2.5, 7, or 14 Vdc and maximum thresholds of 4, 9.5, 17, or 31 Vdc. All 64 channels generate maskable, edge-selectable interrupts with two independent debounce settings for channel groups 1–32 and 33–64, ranging from 16 µs to 1074 seconds in binary increments. ## Technical Specifications • Channels: 64 isolated digital inputs • Input Voltages: 5 Vdc, 12 Vdc, 24 Vdc, 48 Vdc • Input Thresholds: Jumper-selectable minimum (1, 2.5, 7, or 14 Vdc) and maximum (4, 9.5, 17, or 31 Vdc) • Input Current: 0.5 mA, 1.3 mA, 2.8 mA, or 5.8 mA at nominal voltages • Maximum Input Voltage: 60 Vdc per channel; 125 V rms or Vdc between channels or to chassis • Isolation: Optically isolated, rated 125 V rms or Vdc • Debounce: Programmable 16 µs to 1074 seconds, binary increments; two independent settings for channel groups 1–32 and 33–64 • Interrupts: 64 maskable, edge-selectable interrupts with output per 16-bit word • Read Time: 1 ms typical (16-bit register access) • Pull-up Supply: On-board 5 V with 9.4 kΩ effective resistance • Power Requirements: +5 V, +12 V, −12 V, +24 V, −24 V, −5.2 V, −2 V • Terminal Block: Removable screw-type; maximum wire size 16 AWG • Form Factor: C-size, 1-slot VXI module; P1/P2 connectors ## Key Features • Register-based VXI device (A16, slave only) • Parallel strobe-in connections for 32- or 64-bit transfers • Handshake lines for each 16-channel word • TTL-compatible logic levels, 5 V maximum • On-board 5 V pull-up supply for external switch detection ## Typical Applications Industrial automation, laboratory signal monitoring, discrete input acquisition in electrically noisy environments, interrupt-driven system control. ## Compatibility & Integration VXIbus compatible. Functionally similar to Keysight E1459A and Z2404B modules. Uses legacy-style terminal block interface with non-QUIC rails.