Agilent / Keysight E1459A 64-Channel VXI Isolated Digital Input

The Keysight E1459A is a 64-channel VXI isolated digital input module for DC level and edge transition sensing up to 48 Vdc in register-based VXI systems. Optical isolation on all inputs protects against transients up to 125 Vrms or Vdc between channels or to chassis, safeguarding the system from external voltage sources. The module occupies a single C-size slot and operates as a slave device with selectable interrupt levels 1–7.

Technical Specifications

• 64 isolated digital input channels


• Sensing range: DC levels and edge transitions to 48 Vdc


• Maximum input voltage: 60 Vdc (between high and low terminals per channel); 125 Vrms or Vdc (between channels or to chassis)


• Nominal input voltages: 5, 12, 24, and 48 Vdc


• Threshold voltages: 1–4 Vdc (5 V nominal), 2.5–9.5 Vdc (12 V nominal), 7–17 Vdc (24 V nominal), 14–31 Vdc (48 V nominal)


• Input current: 0.5, 1.3, 2.8, or 5.8 mA at nominal voltages


• Minimum input pulse width: 100 ms plus debounce time


• On-board 5 V supply: 4.5–5.5 Vdc output, 16 mA maximum output current


• TTL-compatible logic levels, 5 V maximum Debounce & Data Transfer


• Programmable debounce: 16 µs to 1074 s in binary increments


• Separate debounce periods for channel groups 1–32 and 33–64


• 16-bit word structure with strobe-in, ready-for-data, and interrupt-out per word


• Parallel strobe-in connection for 32- or 64-bit transfers


• VXI register access with D16 interface capability

Key Features

• Optical isolation protects VXI systems from external voltage transients


• Programmable debounce with independent group settings reduces noise sensitivity


• On-board 5 V supply with 9.4 kΩ effective pull-up for switch-state detection


• Flexible data transfer via strobe-in parallel connection


• Interrupter capability with selectable interrupt levels

Typical Applications

• Industrial control systems requiring galvanic isolation


• Multi-channel digital acquisition from isolated sensor networks


• Safety-critical systems with voltage transient protection


• VXI test and measurement systems with mixed-voltage inputs

Compatibility & Integration VXI register-based slave module; A16 addressing; D16 bus interface. Compatible with standard VXI chassis and controllers supporting interrupt-capable modules.