Description
Product Overview
The ABB Bailey IISAC01 is an Analog Control Station designed for single-loop process control and monitoring within the Bailey INFI-90/Harmony control architecture. It provides the operator-facing functions required to monitor process variable, set point, and control output while allowing adjustment of the control loop and selection between manual and automatic operation. ABB documentation describes the SAC as a single printed-circuit-board assembly housed in a panel-mounted enclosure with operator controls and displays.
The ABB IISAC01 is more than a basic analog display. It participates in the control loop and communicates with the associated Multi-Function Processor through an RS-485 serial link. The station receives process and control information from the controller and returns operator commands and control-state information. It also provides an analog-output backup function for the associated CIS module and raise/lower contacts for electric-drive manual operation when required by the system architecture.
The ABB Bailey IISAC01 is particularly relevant to maintenance of older INFI-90/Harmony installations. The unit is documented as compatible with specific control I/O hardware, including the CIO-100, IMCIS12, and IMQRS12, while the serial-link configuration can operate at 5 or 40 kbaud depending on the system.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | ABB Bailey |
| Model | IISAC01 |
| Product Type | Analog Control Station |
| System Family | INFI-90 / Harmony |
| Control Function | Single-loop process control |
| Operating Modes | Manual / Automatic |
| Analog Input Range | +0.75 to +5.25 VDC |
| Input Impedance | >10 MΩ |
| A/D Resolution | 8 bit |
| Analog Input Accuracy | 1.5% of span at 25°C |
| Normal-Mode Rejection | ≥75 dB at 60 Hz |
| Common-Mode Rejection | ≥90 dB at 60 Hz |
| Common-Mode Voltage | ±5 VDC maximum |
| Electric Drive Contact | 100 mA maximum, sink/source |
| M/A Signal | 100 mA maximum, sink/source |
| Power Supply | 21.6–27 VDC |
| Serial Communication | RS-485 |
| Serial Link Speed | 5 or 40 kbaud |
| Typical Communication Partner | MFP module/controller |
| Operating Temperature | 5–40°C |
| Operating Humidity | 20–80% RH, noncondensing |
| Storage Humidity | 10–95% RH, noncondensing |
| Atmospheric Pressure | Sea level to 3 km |
| Air Quality | Noncorrosive |
| Certification | CSA, ordinary/nonhazardous location |
Specifications are based primarily on ABB’s official IISAC01 data sheet and instruction material.
Main Features and Advantages
Single-Loop Process Control
The IISAC01 provides the operator interface and control functions for one analog process loop. It allows the operator to view process information, adjust set point, and select manual or automatic control.
Operator Display
The station incorporates three gas-plasma bar-graph displays for process variable, set point, and control output. An eight-character alphanumeric display provides information such as process value, alarms, set point, operating mode, and error codes.
Manual Backup Capability
One useful field function is the ability to provide analog-output backup for the associated CIS module during a system fault. The station can also provide raise/lower contacts for electric-drive manual operation.
RS-485 Station Communication
The communicates with the MFP through an RS-485 serial link. This link carries initialization, process-variable, set-point, control-output, and operator-command information.
High Input Impedance
The analog input has an impedance greater than 10 MΩ, reducing loading of the upstream signal source. ABB specifies an input range of +0.75 to +5.25 VDC.
Legacy INFI-90 Maintenance
The remains relevant when maintaining existing Bailey control installations where replacing an individual station is preferable to redesigning the control architecture.
IISAC01
Application Scenarios
- Process control loops
- Boiler and auxiliary process control
- Industrial plant control panels
- INFI-90 process-control systems
- Harmony control systems
- Electric actuator control
- Manual/automatic control stations
- Legacy Bailey DCS maintenance
The station is specifically documented as providing process-loop control and monitoring for a single loop.
Engineer’s Guide: Field Pitfalls
WARNING 1 — is not a conventional analog input card
It has analog input circuitry, but its primary role is a complete analog control station, including display, operator controls, loop-control functions, and communication with the controller.
WARNING 2 — Check the firmware revision
The instruction material identifies firmware-dependent compatibility with associated I/O modules. For procurement, the firmware revision should be specified whenever possible, particularly for replacement of an older installed unit.
WARNING 3 — Verify the station link
The communication path is an RS-485 serial station link, not Ethernet. The associated cable is identified in ABB’s INFI-90 documentation as the NKCS01/02 cable family for .
WARNING 4 — Check compatible I/O hardware
The can receive/send information through specific control I/O hardware, including the CIO-100, IMCIS12, and IMQRS12. A replacement should therefore be checked against the actual I/O architecture rather than installed solely because the connector appears compatible.
WARNING 5 — Do not confuse the analog input range with a standard 4–20 mA input
The ABB data sheet specifies +0.75 to +5.25 VDC for the analog input. Do not assume the directly accepts a standard 4–20 mA transmitter without the appropriate interface hardware.
Frequently Asked Questions
What is ABB ?
The is an Analog Control Station providing single-loop process control and monitoring in Bailey /Harmony systems.
Is an analog input module?
Not in the conventional PLC/DCS sense. It contains analog input circuitry, but its overall function is a single-loop operator control station.
What communication interface does it use?
The communicates with the MFP through an RS-485 serial link, with documented 5 or 40 kbaud operating rates depending on configuration.
What is the analog input range?
ABB specifies +0.75 to +5.25 VDC, with input impedance above 10 MΩ and 8-bit A/D resolution.
Can operate a loop manually?
Yes. It provides M/A selection, set-point adjustment, and manual control functions. It also has provisions for analog-output backup and electric-drive raise/lower operation.
What should be checked when purchasing a replacement?
For a used or refurbished , verify:
- Exact model.
- Firmware revision.
- Faceplate displays.
- Membrane switches.
- Analog input circuit.
- RS-485 communication.
- Manual/automatic selection.
- Set-point adjustment.
- Analog output backup.
- Raise/lower contacts.
- Compatibility with the installed I/O module.
- Compatibility with the existing MFP/controller.
Bottom line: ABB Bailey is a single-loop Analog Control Station for the /Harmony control architecture. Its defining functions are operator loop control, process-variable/set-point/output display, RS-485 communication with the MFP, and manual backup capability. For a replacement, firmware, station-link wiring, and associated I/O hardware are just as important as the part number itself.
