ABB CI855K01 3BSE018106R1 | MB300 Dual-Port Comm Module

Description

Key Technical Specifications

Product Introduction

A brownfield plant runs a mix of legacy Advant OCS controllers (AC410, AC450, MasterPiece 200/1) alongside a newer AC 800M system. The plant needs those old controllers to exchange process data with the new system’s operator stations — but they speak different languages. The CI855K01 is the bridge. It plugs into the CEX-Bus slot of an AC 800M controller and speaks MasterBus 300, the protocol that both the legacy ABB controllers and System 800xA operator stations understand natively.

This module gives the AC 800M controller a pair of redundant Ethernet ports dedicated to the MB300 network. The dual-port design means a single cable failure does not knock the communication link offline — the redundant path picks up immediately. Dataset communication, clock synchronization, and point-to-point data exchange all run over this link. For any facility migrating from Advant OCS to AC 800M or System 800xA, this module is often the single piece of hardware that keeps the old and new systems talking during the transition.

ABB CI855K01 3BSE018106R1

QA/QC Transparency SOP

1. Intake & Origin Verification
   Photograph the module label. Capture the CI855K01 designation, the 3BSE018106R1 order code, serial number, and any firmware revision markings. Cross-reference the order code against the ABB spare parts catalog to confirm the module matches the target AC 800M configuration.
2. Visual & Mechanical Inspection
   Inspect the CEX-Bus connector pins for bending, corrosion, or contamination. Check both RJ45 port housings for damage. Verify the module slides cleanly into a CEX slot without forcing. Look for cracked solder joints or burn marks on the PCB.
3. Electrical Parameter Tests
   Measure backplane power rail continuity and verify no short circuits between supply and ground. Check isolation resistance on the Ethernet ports using a calibrated megger. Confirm the module draws expected current when powered through the AC 800M backplane.
4. Live Functional Testing
   Install the module in a test AC 800M rack. Verify the controller recognizes the CI855K01 during hardware scan. Configure a basic MB300 dataset exchange with a test partner node. Confirm data transfers on both redundant ports. Log pass/fail results for each port.
5. Final QC & Anti-Static Packaging
   Label with QC pass status, test date, and firmware revision. Pack in an anti-static shielding bag with foam protection on the CEX-Bus connector. Include a note that the module must be configured in Control Builder M before commissioning.

Field Engineer Gotchas

• TP853 Terminal Board Is Required
  The CI855K01 does not have RJ45 jacks directly on the module face. It mounts onto a TP853 terminal board, which provides the physical RJ45 connectors. If you receive a CI855K01 without the TP853 base, you cannot cable it. Always confirm the terminal board is included or already installed in the rack.
• MB300 Is Not Modbus TCP or PROFINET
  Some surplus listings vaguely describe the CI855 as a generic “Ethernet communication module.” It is not a general-purpose Ethernet card. It speaks MasterBus 300 only. If your network runs Modbus TCP, you need the CI867K01. If it runs PROFINET, you need a different module entirely. Mixing these up wastes commissioning time.
• Firmware Compatibility with AC 800M CPU
  The firmware must be compatible with the AC 800M CPU firmware version running in the rack. A firmware mismatch can cause the controller to fail the hardware scan or drop the MB300 link intermittently. Check the ABB release notes for the specific CPU firmware version before installing.
• Redundancy Requires Correct Network Topology
  The dual ports support redundant networking, but redundancy only works if both ports are connected to separate network segments or switches. Plugging both ports into the same unmanaged switch gives you zero redundancy. Plan the physical cabling before wiring.
• Legacy Controller Address Conflicts
  When bridging between AC 800M and legacy Advant controllers, each node on the network must have a unique address. Duplicate node addresses cause silent data corruption — the system does not always throw a clear fault. Map all node addresses before bringing the link online.

ABB CI855K01 3BSE018106R1

Application Scenarios

• Brownfield DCS migration — Plants upgrading from Advant OCS (AC410/AC450) to AC 800M use the to maintain communication between old controllers and new operator stations during phased migration.
• System 800xA integration — The module enables AC 800M controllers to participate in System 800xA environments where is the backbone protocol for operator station communication.
• Multi-controller data sharing — Facilities running multiple AC 800M controllers use the link for cross-controller dataset exchange and clock synchronization across the plant network.
• Power generation control systems — Thermal and hydro plants with legacy ABB control infrastructure rely on the to maintain communication continuity during controller upgrades without ripping out the entire network.

FAQ

Different protocols. The speaks MasterBus 300 () over Ethernet. The CI854AK01 speaks PROFIBUS DP-V1 over a serial bus. They are not interchangeable. Match the module to the protocol your network requires.

No. It draws 24V DC from the AC 800M backplane through the CEX-Bus slot. No external power connection is needed on the module itself.

Can I hot-swap this module while the controller is running?
Yes — the supports hot-swapping when used with an AC 800M rack. You can pull and replace the module without powering down the controller. However, the network will experience a brief communication interruption during the swap.

Is this module still actively sold by ABB?
Verify with ABB directly. The has been in service for many years across installed bases. Some communication modules in the AC 800M family have been superseded by newer variants. Confirm current availability and any recommended replacement before specifying it for a new project.

The TP853 terminal board. It provides the dual RJ45 connectors for the redundant Ethernet ports and supports DIN rail mounting.

Can I use this module for Modbus TCP communication?
No. The is dedicated to MasterBus 300 protocol only. For Modbus TCP, use the CI867K01 module.