Description
ABB ICST08A9 | 8-Channel Pt100 Input Module | Procontic CS31 Temperature Monitoring
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Model | ICST08A9 |
| ABB Part Number | FPR3335901R1012 |
| System | ABB Procontic CS31 / AC31 |
| Module Type | Analog temperature input remote unit |
| Number of Inputs | 8 |
| Sensor | Pt100 |
| Resolution | 8 bits |
| Sensor Connection | 2-wire / 3-wire |
| Temperature Range | 0 to +300°C |
| Supply | 24 VDC |
| Communication | CS31 system bus |
| Installation | CS31 remote I/O architecture |
ABB’s documentation specifically lists ICST08A9 as an 8-input Pt100 analog input unit with 8-bit resolution and a 0 to +300°C range. The same document identifies FPR3335901R1012 as the 24 VDC version.
The CS31 bus uses an RS-485 physical interface with shielded twisted pair, with 120 Ω termination at the bus extremities. This is important when replacing or extending legacy CS31 remote I/O.
Product Introduction
The ABB ICST08A9 is a legacy Procontic remote analog input unit designed specifically for Pt100 temperature measurement. It provides eight temperature input channels with 8-bit conversion and supports both 2-wire and 3-wire Pt100 sensor arrangements across a 0 to +300°C measurement range.
For maintenance teams, the important point is that ICST08A9 is a temperature-specific remote I/O device, rather than a general-purpose voltage/current analog input. Its replacement must therefore account for the Pt100 configuration, wiring method, address, and the exact power variant.
ICST08A9
Application Scenarios & Field Pitfalls — The Engineer’s Perspective
Engineering Pain Point
Legacy installations often remain in service long after the original I/O hardware becomes difficult to source. A temperature input replacement can appear straightforward, but using the wrong AC31 analog module can change the signal type completely. ICST08A9 is intended for Pt100, with a dedicated temperature range and configuration behavior.
Typical Applications
- Industrial temperature monitoring — Process temperature measurement using Pt100 RTDs.
- Motor and equipment monitoring — Temperature feedback from bearings, housings, and other monitored points where Pt100 sensors are installed.
- Process skids — Multi-point temperature acquisition through remote I/O.
- Legacy PLC/DCS systems — Maintaining existing ABB Procontic installations without changing the field sensor technology.
Technical Pitfalls
- Do not confuse with ICSE08B5. ICSE08B5 is a general analog input unit with 12-bit resolution, while is specifically a Pt100 temperature input unit with 8-bit resolution.
- Check the temperature range. is the 0 to +300°C version. ICST08A8 covers -50 to +150°C, while ICST08A7 covers -20 to +30°C. These are not interchangeable simply because all three use Pt100 sensors.
- Verify 2-wire versus 3-wire wiring. ABB’s documentation explicitly provides different configuration arrangements for the two sensor connection methods.
- Confirm the power variant. FPR3335901R1012 is the 24 VDC version. ABB also documented variants with 120 VAC and 230 VAC references, so the complete part number matters during procurement.
- Preserve the address and configuration. When replacing a remote unit, record the existing hardware configuration and addressing before removing the original device. ABB specifically warns that configuration and wiring should be checked before modification of legacy installations.
- Allow for resolution limitations. The module uses 8-bit conversion. If a migration project requires substantially finer temperature resolution, replacing it with another legacy module of a different specification may require changes to scaling and PLC application logic.
Related Products
- ABB ICST08A8 — 8-channel Pt100 input unit, 8-bit, -50 to +150°C; intended for a lower temperature range than .
- ABB ICST08A7 — 8-channel Pt100 input unit, 8-bit, -20 to +30°C.
- ABB ICSE08B5 — 8-channel general analog input unit with 12-bit resolution; different signal class from .
- ABB ICSE08A6 — 8-channel analog input unit with 8-bit resolution for general analog signals.
- ABB XE08B5 — 8-channel analog extension used in the documented ICMK- replacement architecture and configurable for Pt100 applications.
- ABB ICMK- — Modernization interface used to replace certain older remote units while retaining bus behavior; application restrictions must be checked before migration.
Procurement Note
For a direct spare, specify / FPR3335901R1012 when the existing installation is the 24 VDC version. Before approving an alternate, verify the Pt100 range, 2-wire/3-wire arrangement, address, supply voltage, and existing PLC scaling. A general-purpose analog input card is not an automatic substitute for this temperature-specific unit.
