Acromag IP440-2 Isolated Digital Input Module

The Acromag IP440-2 is a 32-channel optically isolated digital input module for industrial automation systems. It monitors discrete signals across four 8-channel ports, each isolated from logic and from each other. The module protects control systems from electrical noise and ground loops, supporting bipolar input voltages from ±16 to ±40V DC or AC peak.

Input thresholds, debounce times, and polarity are software-programmable, eliminating hardware configuration.

Technical Specifications

Input Characteristics

• 32 optically isolated digital input channels organized into four 8-channel ports


• Bipolar input voltage range: ±16 to ±40V DC or AC peak


• Input threshold (IP440A-2): ±6.8V typical


• Input response time: 10µS typical (off to on), 15µS typical (on to off)


• Selectable debounce: 4µS, 64µS, 1mS, or 8mS


• Improved input hysteresis for noise immunity


• Software-programmable polarity for positive or negative transitions


• Change-of-state interrupts supported via paired channels


• Reverse polarity protection included Isolation and Protection


• Optical isolation across all 32 channels


• Port-to-port isolation and logic-to-field isolation


• Voltage isolation rated 250V AC rms / 250V DC continuous


• 1500V AC dielectric strength test (1 minute, no breakdown)


• ±2.5kV ESD protection System Interface


• Industry Pack (IP) module compatible with standard IP carrier cards


• Conforms to ANSI/VITA 4-1995 specifications


• 0 wait states (250ns cycle) at 8MHz clock


• Four 8-bit reads required to update all channels


• Software configuration; 200mS maximum configuration time after power-up Environmental


• Operating temperature: 0 to 70°C

Key Features

• Port-level isolation eliminates ground loop issues


• Programmable debounce and polarity reduce firmware complexity


• Fast input response times (10-15µS) capture rapid state changes


• Interrupt-capable architecture for event-driven applications


• No jumpers or DIP switches required

Typical Applications

• Discrete signal monitoring in PLC and DCS environments


• Industrial process control with high electrical noise immunity


• Safety-critical systems requiring galvanic isolation


• Multi-source signal acquisition in distributed automation

Compatibility & Integration The IP440-2 integrates with any standard Industry Pack carrier board supporting VITA 4-1995. It interfaces directly with PLCs, DCS platforms, and embedded control systems. The module is a successor to the IP440, offering performance and feature enhancements.