Product Core Brief

• Model: CI854A, full order code CI854AK01, OEM Article No. 3BSE030221R1 / 3BSE030220R1 (complete set with TP854 base)ABB Group
• Brand: ABB Control Systems
• Series: CEX expansion bus communication module for AC800M / System 800xA DCS Controllers (Classic generation, replaced by CI854B)eero
• Core Function: PROFIBUS DP-V1 Class 2 master via CEX bus, matched exclusively with TP854 DIN rail termination base; dual DB9 ports support Profibus media line redundancy, cyclic real-time I/O exchange, DP-V1 HART acyclic diagnostics, compatible with S800/S900 distributed I/O, ACS drives and third-party DP field instrumentsManualsLib.
• Product Type: Slide-in CEX Profibus master communication module, mandatory pairing with TP854 baseplate
• Key Specs: Dual DP-V1 master ports | Media line redundancy | Max 124 DP slaves per module | 500V galvanic isolation | Not RoHS compliant (legacy classic hardware)ABB GroupNote: Limited legacy EOL spare stock available, new projects adopt CI854B; up to 12 CI854A modules per single AC800M controller rack.

Key Technical Specifications

• Power supply: Powered by AC800M internal CEX backplane, max power consumption 5 W
• Profibus protocol: PROFIBUS DP-V0 cyclic real-time I/O + DP-V1 acyclic device parameter & diagnostic access (Class2 Master)
• Baud rate range: 9.6 kbit/s ~ 12 Mbit/s full range software configurable
• Physical interface: TP854 base integrates two female DB9 RS485 connectors for redundant trunk wiring; each segment max 32 slaves, repeaters expand total 124 slaves per CI854A
• Cyclic data throughput: At 12 Mbit/s, total 4000 bytes combined input/output process data
• Minimum bus cycle: 1 ms (single slave at 12 Mbit/s); typical 10–20 ms multi-slave scan
• Redundancy capabilities
  1. Profibus media line redundancy (dual independent cable paths, auto failover)
  2. Support S800/S900 redundant I/O slave stations
• Galvanic isolation: 500 VAC 1-minute dielectric separation between Profibus field side and CEX controller logic
• Supported core functions
  1. HCIR: Add/remove Profibus slave online without full controller stop
  2. HART pass-through: Route DP-V1 HART secondary variables from AI815/AO815 HART I/O modules
  3. Aggregated full slave diagnostics: Wire-break, short-circuit, module undervoltage, slave offline alarms
  4. Automatic primary/secondary trunk cable fault switchover
• PCB coating: ISA-S71.04 G3 industrial conformal coating for mild corrosive power & chemical plant cabinets
• Status indicators: Front multi-color LEDs: PWR, CEX RUN, BUS FAULT, CH1/CH2 Profibus communication status
• Mechanical form: Slide-in card locked to TP854 DIN rail base via alpha mechanical lock (prevents incompatible module forced insertion)
• Operating ambient: 0 °C ~ +55 °C continuous duty; compact vertical racks limited to 0 ~ +40 °C
• Storage range: -40 °C ~ +70 °C, non-condensing RH 5–95 %
• Certifications: CE, UL508, ATEX II 3G Ex nA IIC T4 Gc Zone 2, cULus Class I Div 2 Groups A-D; Not RoHS 2 compliant (legacy classic hardware)ABB Group
• Dimensions (module + base): W59 mm × H185 mm × D127.5 mm; total weight 700 g

Product Introduction

is the classic-generation PROFIBUS DP master expansion module for AC800M DCS, inserted into the controller rack CEX expansion bus to connect all Profibus DP field assets: S800/S900 distributed I/O, ABB ACS variable frequency drives, HART smart valve positioners and third-party DP instruments.Dual independent DB9 ports on base realize full media redundancy, eliminating single cable failure risk for safety-critical control loops. Galvanic isolation suppresses ground-loop EMI noise from long field trunk cables and variable frequency drives, avoiding intermittent I/O value freezing or slave dropout.DP-V1 Class2 master enables direct access to smart device diagnostic data without separate multiplexers; HCIR online modification avoids full process shutdown during field device expansion or replacement. Up to 12 modules can be installed in one AC800M rack to build large-scale multi-segment Profibus plant backbone architectures.Difference vs CI854 / CI854B

1. : Classic legacy, non-RoHS, article 3BSE030221R1, EOL, only for system spare repair replacementABB Group
2. CI854B: New revision, RoHS compliant, enhanced firmware, new projects standard selectioneero
3. CI854: Early original single generation, no optimized DP-V1 HART polling

QA & Testing SOP (Transparency Building)

1. Incoming Inspection: Cross-reference serial numbers and 3BSE part code against ABB AC800M legacy spare databases. Inspect dual DB9 pin integrity, alpha lock matching, full LED bank functionality and intact factory anti-static packaging to filter counterfeit stock.
2. Live Testing: Install onto base inside test rack paired with PM865 CPU simulator. Run continuous 24-hour cyclic Profibus scan testing with mixed S800 I/O, drive and HART instrument slaves while logging stable CEX backplane supply via Fluke 115 multimeter. Simulate primary Profibus trunk disconnection, segment short-circuit and HCIR slave hot-add to validate automatic redundant bus failover and diagnostic flag timing.
3. Electrical Testing: Use 500V Megger to measure insulation resistance between Profibus field circuit and CEX bus logic; pass threshold ≥10 MΩ. Inject 50Hz differential ground-loop noise to confirm no random slave communication loss or bus switchover jitter.
4. Firmware/Config Backup: Record factory default Profibus baud rate, slave address mapping and redundancy parameters via Control Builder M engineering software. Capture high-resolution photos of dual DB9 pinout and wiring layout for field commissioning reference.
5. Final QC & Packaging: Fit plastic dust caps over both DB9 Profibus ports, bundle matched base accessory kit. Place module inside foam-lined anti-static shielding bag, affix a dated QC pass label before sealing in original factory carton.

Installation Pitfalls & Guide

❗Firmware Rev Mismatch Risk: controller firmware older than v5.1.0 lacks CEX register mapping for dual-line redundant bus failover and DP-V1 HART polling logic. Post-replacement, the DCS cannot switch to secondary cable on primary fault and throws intermittent PROFIBUS COMM LOSS alarms. Remediation: Flash matching firmware revision to PM86x CPU before inserting module onto base.❗Non-RoHS Material Warning: is legacy non-RoHS hardware; new greenfield projects must select CI854B instead to meet environmental compliance requirementsABB Group.❗Redundancy Cabling Misconfiguration Risk: Dual Profibus trunk lines must run separate physical cable trays to achieve true fault tolerance; routing both cables in one tray negates media redundancy during tray damage events.❗Profibus Termination Error Risk: Each Profibus segment only installs termination resistor on the farthest end slave device; duplicate or missing termination creates signal reflection, persistent scan jitter and random slave offline faults.❗Alpha Lock Mismatch Warning: base uses fixed A-D alpha mechanical lock; incompatible CEX modules cannot be physically inserted, avoid forced assembly damage.❗CEX Bus Quantity Limit: Max 12 communication modules per controller rack, excess modules trigger CEX bus overload faults.❗ESD Dangers: Ungrounded handling exposes dual Profibus transceiver and CEX bus logic traces to static discharge from dry control room air. Field records show unprotected handling burns both communication channels simultaneously; full process unit downtime labor cost exceeds $1,540. Remediation: Place anti-static mat under controller rack, wear grounded wrist strap, touch bare cabinet chassis ground for 3 seconds before handling module.

4-step replacement guide

1. Pre-install: CEX communication modules do not support official hot-swap; execute full rack lockout/tagout of 24V auxiliary power. Photograph dual DB9 trunk wiring layout, Profibus segment address mapping and redundancy mode configuration. Pause all Profibus cyclic polling logic blocks in Control Builder M.
2. Removal: Unlatch base retention clip, slide upward out of base slot, disconnect dual DB9 Profibus trunk cables and store unit in static-safe sleeve.
3. Install: Insert new fully into base and lock retention latch; reconnect dual redundant Profibus trunk cables to matching DB9 ports, install end-of-line termination resistor on each segment’s farthest slave.
4. Power-on Test: Restore rack 24V auxiliary power first; verify front CH1/CH2 COM LEDs illuminate steady green, perform full Profibus slave scan to confirm all field devices communicate correctly, test primary cable disconnection to validate automatic redundant failover before re-enabling automatic DCS closed-loop control.

FAQ

Q: Can be hot-swapped while the controller rack remains powered?A: No. CEX communication interface modules have no ABB hot-swap certification. Live extraction generates destructive voltage transients that crash the entire CEX bus and corrupt controller process image tables. Complete rack 24V power isolation is mandatory for replacement.

Q: Does this Profibus master module carry original OEM factory warranty when purchased as new surplus?A: ABB original factory production warranty expired for EOL legacy hardware. All surplus and refurbished inventory passes full in-house bench QA testing and carries a 12-month internal stock replacement warranty, limited to manufacturing defects detected during validation testing.

Q: Can CI854B serve as a direct drop-in replacement for ?A: Mechanical base fit fully compatible, pinout and wiring identical. is RoHS compliant updated revision with optimized firmware; after replacement only verify full Profibus slave scan and redundancy function, no field wiring modification required.

Q: What minimum CPU firmware version enables full dual-line redundancy and DP-V1 HART support?A: PM86x controller firmware v5.1.0 or newer. Older firmware omits redundant bus switchover register mapping and cannot retrieve HART secondary variable diagnostic data over DP-V1.

Q: Will Profibus slave address, baud rate and redundancy configuration persist after module replacement?A: All bus configuration data resides in CPU non-volatile memory; no local parameter storage on hardware. No full reconfiguration required post-swap, only complete Profibus slave scan and redundancy failover verification.

Q: Is compatible with legacy Advant AC450 / MasterPiece DCS racks?A: No. uses modern CEX expansion bus architecture, with zero electrical and mechanical compatibility with Advant AC450 CEX bus CI54x communication modules.

Q: How many Profibus slave devices can one master port connect?A: Single segment maximum 32 slaves; with Profibus repeaters cascaded, total up to 124 DP slave nodes per module dual-port trunk system.