Hitachi AEH Series Modules AEH002A DCS I/O Card

Technical Dossier

Product Details And Specifications

Hitachi AEH Series Technical Notes

The Evolution of AEH Series Architecture

The AEH Series was introduced as a modular I/O expansion family for Hitachi's mid-generation DCS controllers, designed to interface with both analog field instruments and digital actuator networks via a standardized backplane bus. Early-generation modules (AEH001x variants) used parallel bus addressing with fixed-slot assignment, requiring manual DIP-switch configuration for node identification. Mid-generation revisions (AEH002x, AEH003x) introduced software-configurable addressing and improved noise immunity through optocoupler isolation on all digital input channels. Late-generation variants added support for HART pass-through on analog input channels, enabling field device diagnostics without loop interruption. Compatibility across generations is constrained by backplane revision: modules from the AEH001x generation are not hot-swap compatible with AEH003x-era racks without firmware and backplane upgrades. Engineers maintaining mixed-generation installations must verify rack revision codes (stamped on the backplane PCB edge) before substituting modules. The series has no direct pin-compatible successor within Hitachi's current catalog; migration to Hitachi's HISEC-V or third-party DCS platforms requires full I/O remapping and signal conditioning review.

AEH Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked modules within the Hitachi AEH Series. Each entry reflects the module's primary functional classification and channel configuration as documented in Hitachi DCS engineering references.

Analog Input Modules

• AEH001A: 8-ch analog input, 4–20 mA, 12-bit resolution, single-ended
• AEH001B: 8-ch analog input, 1–5 V DC, 12-bit, with open-circuit detection
• AEH002A: 16-ch analog input, 4–20 mA, 13-bit resolution, optocoupler isolated
• AEH002B: 16-ch analog input, thermocouple types J/K/T/E, cold-junction compensated
• AEH002C: 16-ch analog input, RTD (Pt100/Pt1000), 3-wire, 14-bit resolution
• AEH003A: 32-ch analog input, 4–20 mA, HART pass-through, multiplexed scan

Analog Output Modules

• AEH011A: 8-ch analog output, 4–20 mA, 12-bit, loop-powered with short-circuit protection
• AEH012A: 16-ch analog output, 4–20 mA, 13-bit, with output readback verification
• AEH013A: 8-ch analog output, 0–10 V DC, 12-bit, isolated per channel

Digital Input Modules

• AEH021A: 32-ch digital input, 24 V DC, sink type, LED status per channel
• AEH021B: 32-ch digital input, 120 V AC, optocoupler isolated, surge protected
• AEH022A: 64-ch digital input, 24 V DC, high-density, multiplexed addressing

Digital Output Modules

• AEH031A: 32-ch digital output, 24 V DC, source type, 0.5 A per channel, short-circuit protected
• AEH031B: 16-ch digital output, relay contact, 250 V AC / 2 A, Form C contacts
• AEH032A: 64-ch digital output, 24 V DC, transistor sink, 0.3 A per channel

Communication & Interface Modules

• AEH041A: RS-232C/RS-485 serial communication adapter, Modbus RTU master/slave
• AEH042A: PROFIBUS-DP slave adapter, 12 Mbps, GSD file configurable
• AEH043A: Ethernet TCP/IP interface module, 10/100 Mbps, Modbus TCP support