Product Core Brief

• Model: TC625 3BSE002224R1
• Brand: ABB
• Series: Advant OCS / Symphony Plus AF100 fieldbus communication hardware
• Core Function: Converts twisted pair AF100 signals to coaxial cable media for long-distance distributed I/O networking
• Product Type: DIN rail mounted AF100 coaxial bus modem
• Key Specs: 10Mbps bus speed | 1500VAC galvanic isolation | BNC coaxial + D-Sub9 copper interfaces
• Note: Full platform end-of-life; factory sealed new units and continuous load-tested surplus available for legacy power and chemical plant DCS maintenance

Key Technical Specifications

• Bus Protocol: ABB proprietary AF100 Advant Fieldbus 100, 10 Mbps fixed baud rate
• Physical Interfaces: Male D-Sub9 for twisted pair copper bus, 50Ω BNC coaxial port
• Max Coaxial Cable Reach: 1000 meters RG6 coaxial cable; 2000 meters shielded twisted pair
• Galvanic Isolation: 1500 VAC isolation between coaxial field media and internal logic circuits
• Auxiliary Operating Supply: 24 VDC ±10% SELV, 150 mA nominal power draw
• Diagnostic Indicators: Front green RUN power LED, real-time Tx/Rx traffic status lights
• Mechanical Mount: Standard 35 mm EN 50022 DIN rail clip-in housing
• Enclosure rating: IP20 for interior control cabinet installation
• PCB protection: ISA S71.04 G3 conformal coating for coastal high-humidity sites
• Operating ambient temperature: 0°C to +50°C sealed cabinet; storage -40°C to +85°C
• Humidity limit: ≤75% RH non-condensing below 55°C
• Net weight: 0.73 kg
• Overall dimensions: 117 mm D × 45 mm W × 148.5 mm H
• Compliance Standards: IEC 60255, CE certified, ISO 9001 OEM production

Product Introduction

This DIN rail media converter bridges standard twisted pair bus wiring to coaxial trunk lines, eliminating EMI interference from motor MCCs and variable frequency drives on long plant cable runs. Its internal isolation barrier blocks ground loop voltage transients that cause measurement drift, and dedicated Tx/Rx LEDs let technicians verify live bus traffic without diagnostic software tools.

QA & Testing SOP

1. Incoming Inspection: Cross-reference serial number against ABB Advant spare asset database to filter counterfeit assemblies; inspect BNC coaxial port, D-Sub9 connector and front LED array with a 10x magnifier for thermal discoloration or pin corrosion; log serial numbers for full power station traceability records.
2. Live Testing: Mount the unit on a DIN rail test bench paired with a CI522 communication interface and mixed analog/digital I/O load bank; supply rated 24VDC auxiliary power; run a continuous 24-hour cycle test including coaxial cable fault injection, full 10Mbps bus throughput validation and real-time Tx/Rx LED trigger confirmation.
3. Electrical Testing: Use a Fluke 115 insulation tester to verify ≥10MΩ isolation between coaxial signal terminals and DIN rail chassis ground; measure cabinet PE continuity resistance below 0.5Ω.
4. Firmware/Config Backup: Photograph front LED traffic mapping and OEM maximum coaxial cable length limits printed on the unit housing for field wiring reference.
5. Final QC & Packaging: Wipe plastic housing with static-dissipative microfiber cloth; cap BNC and D-Sub9 ports with insulating dust covers; seal the unit inside a shielding ESD bag, attach a printed QC tag with full 24-hour bus communication test timestamp, then pack into foam lined transit cartons.

Installation Pitfalls & Guide

❗ Mismatched 50/75Ω coaxial cable creates signal attenuation: Only 50Ω RG6 coaxial cable is approved; 75Ω CCTV cabling cuts bus throughput by 60% and triggers constant scan timeouts. ❗ Dirty BNC center pins block bus transmission: Oil residue from bare finger contact degrades signal coupling within 90 days of coastal site operation; clean all coaxial connectors with OEM alcohol wipes before cabling. ❗ Over-torqued D-Sub9 screws crack PCB copper traces: Excessive tightening creates intermittent twisted pair bus dropout during cabinet thermal cycling. ❗ ESD discharge destroys internal bus transceiver ICs: Bare finger contact with PCB signal traces disables both coaxial and copper bus ports, requiring full unit replacement and multi-hour production downtime. ❗ Hot-swap energized 24VDC supply corrupts bus framing data: Removing the unit under live auxiliary power forces all connected I/O modules to cold restart, creating a plant monitoring blind zone.

4-step replacement guide

1. Pre-install: Lock out and tag cabinet 24VDC auxiliary power supply; wait 10 minutes for internal logic capacitors to fully discharge; don ESD wrist strap; capture photos of BNC coaxial cabling and D-Sub9 twisted pair wiring layout.
2. Removal: Disconnect all coaxial and twisted pair communication cables one by one; release the DIN rail retention clip, slide the hardware horizontally off the rail without bending BNC center pins.
3. Install: Clip the new unit firmly onto the original DIN rail position; re-terminate twisted pair wiring to OEM torque specs, clean BNC connector pins before seating coaxial cables to match photographed routing.
4. Power-on Test: Restore 24VDC auxiliary power; confirm steady green RUN LED and active Tx/Rx traffic indicators; trigger full bus scan to verify all remote I/O point data uploads to the DCS HMI without packet loss; simulate coaxial cable pull to confirm real-time fault indication.

FAQ

Q: Can this unit operate without coaxial cabling connected? A: It will communicate with local twisted pair I/O clusters, but all remote coaxial-linked I/O segments remain offline. The BNC port is required for extended plant bus layouts exceeding 2km twisted pair cable limits. Q: Is hot-swapping supported while cabinet 24VDC auxiliary power remains energized? A: It is not supported. Live extraction disrupts the differential bus clock signals and triggers mass I/O communication failures, which disable process monitoring loops. Full power lockout and capacitor discharge wait time are mandatory. Q: What warranty coverage applies to stocked units? A: Factory-new original coaxial modems carry a 12-month OEM warranty covering BNC coaxial transceivers, twisted pair bus isolation circuits and Tx/Rx diagnostic LED arrays. Load-tested surplus units come with a 6-month functional warranty. Damage from mismatched impedance coaxial cable, ungrounded ESD handling or energized hot-swap removal voids all coverage. Q: What hardware replaces this unit for new plant builds? A: New 800xA deployments use CI867 fiber-enabled communication interfaces that eliminate separate coaxial media conversion hardware. This hardware remains approved only for one-to-one maintenance replacement of pre-2020 Advant OCS bus systems. Q: Will stored bus timing settings be lost after full cabinet power outage? A: All bus timing parameters rely on passive PCB resistor networks, so power loss does not alter signal timing. No on-board non-volatile memory stores custom configuration data, so no program retention functions exist on the hardware. Q: What are the most common failure modes for a faulty unit? A: Persistent red fault state with undamaged coaxial cabling, one-way bus transmission with zero receive data, complete loss of communication to all remote coaxial I/O clusters, inconsistent scan timing under maximum twisted pair load, and failure to detect coaxial cable breakage events for fault logging to the controller.