The CI854BK01 is a vital component of the ABB AC 800M series high-performance controller family. It is a professional communication expansion module kit, consisting of the CI854B Communication Expansion Module (CEM) and the TP854 Communication Expansion Baseplate (CEB). The primary function of this kit is to provide a powerful, flexible, and reliable PROFIBUS DP (Decentralized Periphery) fieldbus master interface for the AC 800M controller, enabling high-speed data exchange between the controller and numerous distributed intelligent slave devices in the field (such as remote I/O, drives, sensors, actuators, etc.).
PROFIBUS DP is one of the most widely used fieldbus standards in industrial automation, renowned for its high real-time performance, stability, and robust diagnostic capabilities. The CI854BK01 fully complies with the PROFIBUS DP protocol standard. It not only supports standard master-slave communication but also integrates advanced features such as Line Redundancy, Master Redundancy, and Slave Redundancy, and supports Hot Swap. This makes it suitable for mission-critical applications with stringent availability requirements, such as process industries, power generation, and transportation.
The module is powered and connected via the CEX-Bus (Communication Extension Bus) from the AC 800M processor unit, eliminating the need for an external independent power supply, simplifying system wiring, and improving integration. Its compact DIN-rail mounting design allows for easy integration into standard control cabinets.
2. Core Features & Characteristics
The CI854BK01 is designed to deliver the highest level of communication reliability and flexibility. Its core features and characteristics are detailed below:
1. High-Performance PROFIBUS DP Master:
As a PROFIBUS DP Master (conforming to Class 1 and Class 2 standards), the CI854BK01 can cyclically exchange process data (inputs/outputs) with slave devices and provide acyclic services for parameter setting, diagnosis, and reading.
Supports selectable communication speeds from 9.6 kbit/s to 12 Mbit/s, allowing users to flexibly configure the network based on its scale and real-time requirements to optimize performance.
2. Line Redundancy:
The TP854 baseplate integrates two independent female DB9 connectors (PROFIBUS A and PROFIBUS B), allowing connection of two physically separate PROFIBUS DP cables to form redundant communication lines (Line A and Line B).
If one line fails due to cable break, connector fault, or interference, communication automatically and seamlessly switches to the other backup line, ensuring uninterrupted bus communication and significantly enhancing network availability.
3. Master Redundancy - A Key Feature of CI854B:
The CI854B module supports forming a primary-backup redundant pair with another module of the same type.
In a redundant configuration, one module operates as the "Primary" module, handling all bus communication, while the other acts as the "Backup."
If the primary module fails (e.g., hardware fault or receives a fault signal from the processor unit), the backup module automatically and rapidly switches over to take control of the PROFIBUS DP network, ensuring high availability at the master level. This feature requires corresponding configuration in CBM (Control Builder M) software.
4. Support for Slave Redundancy:
The interface supports connecting PROFIBUS DP slave devices with redundancy functionality. If the primary slave fails, the system can switch to the backup slave, ensuring continuous availability of field I/O points.
5. Hot Swap Support:
The CI854B module supports online hot swap functionality. This means the module can be safely removed or installed while the system is powered on and the main controller and other bus modules are operating normally.
This feature greatly facilitates system maintenance, module replacement, and expansion without requiring a shutdown, which is crucial for continuously operating plants. Note: The earlier CI854 model does not support hot swap.
6. Powerful Network Expansion Capability:
A single PROFIBUS DP segment can connect up to 32 nodes (masters + slaves). Using repeaters, the maximum number of nodes in the entire network can be extended to 124, meeting the needs of large-scale distributed control systems.
7. Comprehensive Diagnostics & Status Indication:
The module's front panel is equipped with a set of multi-color LED indicators providing intuitive feedback on operational status, fault information, and communication activity:
* Run (R) / Green: Module is powered on and operating normally.
* Fault (F) / Red: Module has detected an internal or configuration error.
* Receive A (RxA) / Yellow: Indicates data communication activity on Line A (flashing or steady).
* Receive B (RxB) / Yellow: Indicates data communication activity on Line B.
* Primary (PRIM) / Yellow (CI854A/B only): In a redundant configuration, indicates this module is currently in the "Primary" state.
* Dual (DUAL) / Yellow (CI854A/B only): Indicates the module is currently operating in a redundant configuration mode.
8. Mechanical & Electrical Safety Design:
Code Lock Mechanism: The TP854 baseplate features a pre-set two-letter alpha code locking device that prevents the installation of incompatible communication module types, effectively avoiding human installation errors.
Galvanic Isolation: Effective galvanic isolation is implemented between the PROFIBUS DP interface and the internal CEX-Bus, enhancing noise immunity and protecting the controller-side equipment.
Shield Grounding: The PROFIBUS DP cable shield must be connected to functional ground at both ends of the cable (including at the CI854BK01 connector) to ensure optimal electromagnetic compatibility (EMC), even though the CI854B/TP854 already connects the shield to ground internally via its connectors.
3. Hardware Composition & Architecture
The CI854BK01 kit consists of two main physical components with distinct roles:
1. TP854 Communication Expansion Baseplate (CEB):
This is a "passive" component, fixed onto the DIN rail.
Its main function is to provide physical connection interfaces, including:
* CEX-Bus input/output connectors for connecting to the AC 800M processor unit.
* An 80-pin edge connector slot for inserting the CI854B module.
* Two female DB9 connectors (A & B) for connecting the redundant PROFIBUS DP networks.
Once the baseplate is installed and wired, it remains untouched during module replacement or maintenance, ensuring stability of the field wiring.
2. CI854B Communication Expansion Module (CEM):
This is the "intelligent," pluggable module containing all core electronics.
Its internal architecture is based on a powerful MPC880 CPU and integrates key components:
* FPGA (Field-Programmable Gate Array): Model Xilinx XC3S1000, embedding a NIOS soft-core processor dedicated to handling the PROFIBUS DP protocol stack for efficient real-time communication.
* Memory: Includes Flash, DDR2 RAM, and serial Flash PROM for storing programs, data, and configuration.
* Line Redundancy Unit: Manages switching and monitoring between the two physical PROFIBUS DP lines.
* DC/DC Converter: Converts the +24V DC power from the CEX-Bus into the various voltages required internally (e.g., +5V, +3.3V).
* LED Status Indicators.
* CEX-Bus Interface Logic & Dual-Port Memory: Enables fast data exchange with the AC 800M controller.
Brief Workflow: The AC 800M controller sends control commands and data to the CI854B via the CEX-Bus. The CPU and PROFIBUS FPGA inside the CI854B module collaborate to encapsulate this data into telegrams according to the PROFIBUS DP protocol and send them to the fieldbus network via the connectors on the TP854 baseplate. Simultaneously, data received from slave devices on the network is uploaded to the controller via the CEX-Bus. The Line Redundancy Unit continuously monitors the quality of both lines and performs switching when necessary.
4. Installation & Commissioning Key Points
Mechanical Installation: First, fix the TP854 baseplate onto a standard DIN rail. Then, align the CI854B module with the baseplate's 80-pin slot and insert it along the rail direction until it locks into place. The code lock mechanism ensures only the correct module type can be installed.
Bus Connection: Use shielded twisted-pair cables conforming to PROFIBUS DP specifications. Cable wire A (green, corresponding to RxD/TxD-N) should be connected to PIN 8 of the DB9 connector, and wire B (red, corresponding to RxD/TxD-P) to PIN 3. It is crucial that the cable shield is connected to functional earth at both ends of the cable. Even though the CI854 connector provides internal grounding, an external ground connection (e.g., using a grounding clamp) at the termination point is still required to comply with standards and achieve optimal noise immunity.
Bus Termination: The PROFIBUS DP network must be terminated with resistors at the two physical end nodes. This is typically done using DB9 plugs with built-in, switchable termination resistors. At the CI854BK01 end, if it is located at one end of the bus, set the termination resistor switch on the corresponding connector to "ON"; if it is in the middle of the network, set it to "OFF."
Redundant Configuration Wiring:
Line Redundancy: Connect two independent PROFIBUS DP cables to the "PROFIBUS A" and "PROFIBUS B" ports on the TP854, respectively.
Master Redundancy: Requires two CI854B modules installed on their respective TP854 baseplates. Their PROFIBUS A ports should be connected in parallel to the same physical Network A, and PROFIBUS B ports to the same physical Network B. Termination resistors must be activated at both ends of each physical network.
Software Configuration: In ABB's engineering software Control Builder M (CBM), the AC 800M controller hardware must be configured by adding the CI854B module and setting its PROFIBUS DP master parameters (e.g., station address, baud rate), the list of slaves to be scanned, and their I/O mapping. Redundancy features also require specific redundancy parameter settings in CBM. After configuration, download it to the controller.
5. Maintenance & Troubleshooting
The CI854BK01 provides comprehensive LED indicators and system diagnostics for quick problem identification:
No LEDs are lit: Check if the CI854B module is included in the controller configuration and downloaded; check the CEX-Bus fuse inside the PM8xx processor unit; attempt to issue a reset (INIT) signal from the controller.
Fault (F) LED Red is ON: Could be during module startup/configuration (wait for completion), or a configuration error exists. Check diagnostic information in CBM. Attempt a reset; if the fault persists, consider replacing the module.
RxA or RxB LED is OFF: Indicates no communication on the corresponding line. Check if slaves are configured and connected on that line; check if redundant slaves are functioning correctly; inspect cables and connectors on that line for damage or poor connections.
DUAL LED is OFF (in redundant mode): Check if module redundancy is correctly configured and the configuration is downloaded in CBM.
Thanks to Hot Swap capability, if a module hardware fault is suspected, module replacement can be attempted while the system is running (ensuring safe conditions are met), allowing for rapid system function recovery.
