The ABB 07AC91 (GJR5252300R0101) is a high-density, versatile analog input/output module belonging to the Advant Controller 31 (AC31) series and the Advant OCS (Open Control System) family. It is designed to function as a remote I/O unit on the CS31 system bus, providing a bridge between field-level analog sensors/actuators and the central PLC (Programmable Logic Controller).
This module is unique for its “dual-mode” configuration capability, allowing engineers to prioritize either high channel density or high signal resolution depending on the specific requirements of the industrial process. Its ruggedized design and galvanic isolation make it a standard choice for distributed automation in harsh environments.
Product Parameters (Datasheet)
The technical performance of the 07AC91 is defined by two primary operating modes, selectable via internal DIL switches:
| Parameter | Specification |
| Model Number | 07AC91 |
| Product ID | GJR5252300R0101 |
| Module Type | Analog Input/Output Module (Remote) |
| System Bus | CS31 System Bus (Electrically Isolated) |
| Operating Voltage | 24 V DC (+18V to +30V) |
| Current Consumption | Max. 0.2 A |
| Power Dissipation | Max. 5 W |
| Resolution (Mode 1) | 12-bit + Sign: 8 Inputs and 8 Outputs |
| Resolution (Mode 2) | 8-bit: Up to 16 Channels (Configurable in pairs) |
| Signal Ranges | ±10 V, 0-10 V, 0-20 mA (Configurable) |
| Conversion Error | Typically 0.5%, Max 1.0% |
| Diagnostic Display | 17 Status LEDs (Front Panel) |
| Protection Class | IP20 |
| Mounting | DIN Rail (35mm) |
Technical Description & Operational Modes
The 07AC91 is highly adaptable due to its dual-mode logic, which changes how the module handles data words on the CS31 bus:
- 12-bit Operating Mode: In this configuration, the module provides 8 dedicated analog inputs and 8 dedicated analog outputs. Each channel is individually configurable for voltage (±10 V) or current (0…20 mA). This mode is utilized for precision tasks such as temperature control and pressure monitoring where small signal variations are critical.
- 8-bit Operating Mode: This mode maximizes channel density. It provides up to 16 channels that can be set in pairs as either inputs or outputs. To optimize bus traffic, two 8-bit analog values are packed into a single data word. This is ideal for general monitoring where speed and quantity of signals outweigh extreme precision.
- Isolation & Diagnostics: The CS31 bus connection is electrically isolated from the internal logic and I/O circuitry to prevent noise propagation. The front panel features 17 LEDs: one for power/ready status and 16 to provide channel-specific diagnostics, such as overload or wire-break detection.
Country of Origin
- Primary Origin: Germany (DE).
- Secondary Production/Hubs: Sweden (SE).
Product Related News
In recent years (2025–2026), the ABB 07AC91 has transitioned into a “Legacy Support” phase within the ABB Lifecycle management program. Despite being an older series compared to the AC500, the 07AC91 remains in high demand due to the vast global install base of Advant Controller 31 systems in sectors like water treatment and infrastructure.
Recent industrial news emphasizes the “Sustained Availability” of these modules through ABB’s specialized refurbished parts program. As companies move toward digital transformation, ABB has introduced software bridges that allow the 07AC91 to communicate with the ABB Ability™ platform. This allows legacy users to implement cloud-based predictive maintenance and data analytics without replacing their existing, reliable AC31 hardware, effectively extending the lifecycle of the 07AC91 for another decade.
Application Areas
- Power & Energy: Monitoring generator parameters and auxiliary transformer signals.
- Water Treatment: Controlling pump speeds via 4-20mA signals and monitoring flow rates.
- Metallurgy: Precise control of furnace temperature and hydraulic valve positioning.
- Chemical Processing: Managing mixing ratios through high-precision analog loop control.
Recommended Related ABB Models
If you are maintaining or expanding a CS31 or Advant-based system, the following modules are frequently used alongside the 07AC91:
- 07KT97 / 07KT98: The primary PLC central units (CPUs) that act as the master for the 07AC91 on the CS31 bus.
- 07AI91: A dedicated 8-channel analog input module for high-density sensor acquisition.
- 07DC91: A 16-channel digital input/output module for monitoring switches and controlling relays.
- 07KR91: A compact central unit used in smaller distributed automation cells.
- AC500 Series (PM571/PM581): The modern successor family for users looking to migrate from the legacy AC31/Advant architecture to an Ethernet-based DCS.
- CI590-CS31: A communication interface used to bridge legacy CS31 I/O modules into modern AC500 control systems.
