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.