GE 8104 Series Modules – 8104-AO-IP-03 8104-AO-IP

Technical Dossier

Product Details And Specifications

GE 8104 Series Technical Notes

The GE 8104 Series analog output modules are a core component of General Electric's Series 90-70 Programmable Logic Controller (PLC) platform, one of the most widely deployed industrial control architectures in global heavy industry. Installed across petrochemical refineries, nuclear power generation facilities, offshore oil & gas platforms, and large-scale chemical processing plants, the 8104 Series represents GE Fanuc Automation's engineering standard for high-density, isolated analog output signal conditioning. These modules interface directly with the Series 90-70 VME-based backplane, providing 4–16 channel current and voltage output capability to field instruments including control valves, variable frequency drives, and positioners. Their continued presence in brownfield DCS/PLC hybrid architectures makes them a critical spare parts category for facilities operating legacy GE control systems through extended lifecycle programs.

The Evolution of 8104 Series Architecture

The 8104 Series was introduced as part of GE Fanuc's Series 90-70 platform, launched in the late 1980s as a rack-based, VME-bus PLC system designed to compete with Siemens S5 and Allen-Bradley PLC-5 in large-scale process control applications. The 8104 analog output family was engineered to deliver galvanically isolated 4–20 mA and 0–10 V DC outputs with 12-bit resolution, meeting the signal integrity requirements of instrumentation loops in hazardous process environments.

Through the 1990s, GE Fanuc expanded the 8104 range to include isolated-per-point (IP) variants — designated by the -IP suffix — which provide individual channel isolation, a critical requirement in nuclear and chemical plant environments where ground loops and common-mode interference are primary failure modes. The 8104-AO-IP-03 and 8104-AO-IP represent the mature, production-stable revision of this isolated output architecture.

With GE's transition to the PACSystems RX7i and RX3i platforms in the 2000s, the Series 90-70 entered a managed end-of-life phase. GE Intelligent Platforms (later Emerson Automation Solutions following the 2018 acquisition) continued to supply 8104 Series modules under extended support agreements, but new production has ceased for most variants. Facilities running Series 90-70 racks must now source 8104 modules through certified aftermarket channels to maintain operational continuity.

8104 Series Full Catalog & Functionalities (SKU List)

Analog Output Modules — Isolated Per Point (IP)

• 8104-AO-IP-03: 4-channel isolated analog output, 4–20 mA / 0–10 V, 12-bit resolution, Series 90-70 VME backplane
• 8104-AO-IP: Base isolated analog output module, 4-channel, current/voltage configurable per channel
• 8104-AO-IP-04: 4-channel isolated AO, extended temperature rating, enhanced EMI shielding revision
• 8104-AO-IP-08: 8-channel isolated analog output, 4–20 mA, individual channel isolation, Series 90-70 compatible

Analog Output Modules — Standard (Non-Isolated)

• 8104-AO-01: 4-channel analog output, 0–10 V / 4–20 mA, common ground reference, 12-bit DAC
• 8104-AO-02: 4-channel AO, voltage output only, 0–10 V DC, Series 90-70 rack mount
• 8104-AO-04: 4-channel AO, current output 4–20 mA, non-isolated, standard backplane interface
• 8104-AO-08: 8-channel analog output, non-isolated, 12-bit, high-density field wiring terminal

Analog Input Modules (AI) — Series 8104 Compatible

• 8104-AI-IP-04: 4-channel isolated analog input, 4–20 mA, 12-bit ADC, Series 90-70
• 8104-AI-IP-08: 8-channel isolated analog input, voltage/current selectable, individual channel isolation
• 8104-AI-01: 4-channel AI, 0–10 V / 4–20 mA, non-isolated, standard Series 90-70 slot
• 8104-AI-04: 4-channel AI, current input, 12-bit resolution, common ground
• 8104-AI-16: 16-channel analog input, multiplexed, 12-bit, high-density process monitoring

Digital I/O Modules (DI/DO) — 8104 Rack Compatible

• 8104-DI-DC-16: 16-channel 24 VDC discrete input, Series 90-70 VME slot, IEC 61131-2 compliant
• 8104-DO-DC-16: 16-channel 24 VDC discrete output, transistor sourcing, 0.5 A per channel
• 8104-DO-RL-08: 8-channel relay output, Form C contacts, 2 A / 250 VAC, isolated coil drive

Power Supply & Backplane Accessories

• 8104-PS-AC: Series 90-70 rack power supply, 120/240 VAC input, 5 VDC / 24 VDC output rails
• 8104-BP-12: 12-slot VME backplane for Series 90-70, supports CPU and I/O module mix

Quality Control for the 8104 Series Range

The 8104 Series analog output modules present specific test challenges due to their isolated-per-point architecture and VME backplane interface. DriveKNMS applies the following test protocol to all 8104 units prior to dispatch:

• Backplane Interface Verification: Each module is seated in a Series 90-70 test rack and interrogated via the VME bus to confirm correct slot addressing and module ID response.
• Channel Isolation Test: For IP-suffix variants, inter-channel isolation resistance is measured at 500 VDC to verify galvanic separation integrity. Minimum acceptable isolation: 100 MΩ.
• DAC Linearity Check: All output channels are swept across the full 12-bit range (0–4095 counts) and output current/voltage is measured at calibrated reference points (0%, 25%, 50%, 75%, 100% of span).
• Loop Compliance Voltage Test: Current output channels are loaded to maximum compliance voltage to verify driver stage integrity under worst-case field wiring conditions.
• Thermal Burn-In: Units are powered for a minimum of 4 hours at ambient temperature to screen for early-life component failures prior to shipment.