Product Core Brief
- Model: DAI04, OEM part number 0369632M
- Brand: ABB Hartmann & Braun
- Series: Freelance 2000 legacy DCS rack I/O
- Core Function: Convert thermocouple, RTD and millivolt field sensor signals to digital process values
- Product Type: Slide-in rack analog input board for DRA02 subracks
- Key Specs: 8 multi-type analog channels | 12-bit ADC resolution | Optical field-to-backplane isolation ⚠️ EOL — limited stock remaining, Condition: New Surplus
Product Introduction
ABB is a dedicated temperature and low-level analog input board built exclusively for Freelance 2000 DRA02 rack assemblies, engineered for boiler, furnace and reactor thermal monitoring loops.This unit differs from current-loop DAI01/DAI03 variants by natively supporting mV, RTD and thermocouple inputs; its built-in cold-junction compensation eliminates external signal conditioning and caps full-scale measurement error at 0.5 %, a key tolerance for safety temperature interlocks.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Total analog channels | 8 configurable low-level input channels |
| Supported sensor signal types | mV, Pt100/Pt1000 RTD, J/K/S/R/T/N thermocouples |
| ADC conversion resolution | 12-bit linear conversion |
| Max full-scale measurement error | ≤ 0.5 % FS under nominal cabinet temperature |
| Galvanic isolation method | Optical isolation, field side to Freelance rack backplane |
| Backplane operating supply | 24 V DC ± 10 %, 65 mA typical current draw |
| Full module scan cycle time | 100 ms for all 8 active sensor channels |
| Max allowable field cable length | 600 m shielded twisted pair wiring |
| Operating ambient temperature | 0 °C to +60 °C full rated precision |
| Storage temperature range | -40 °C to +70 °C, non-condensing 5–95 % RH |
| Physical dimensions | W326 mm × H20 mm × D216 mm |
| Net unit mass | 0.30 kg |
| Certified rack compatibility | DRA02 12-slot Freelance subracks only |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-reference serial numbers against ABB Freelance spare parts databases; inspect gold edge connectors for oxidation, front channel LED functionality, PCB traces for scratch damage. Match OEM anti-static packaging seals to filter counterfeit surplus inventory.
- Live Functional Test: Seat the unit inside a DRA02 test rack paired with a Freelance controller simulator and calibrated resistance decade boxes / thermocouple signal generators; run continuous 24-hour cyclic channel scanning while toggling RTD and thermocouple sensor modes. Log stable 24 V supply and board temperature with a Fluke 115 multimeter through the full cycle.
- Electrical Parameter Test: Use a 500 V Megger to measure field channel to backplane isolation resistance; pass threshold set above 10 MΩ. Inject long-wire lead resistance loads to confirm zero measurable temperature offset across all 8 channels.
- Firmware Verification: No user-adjustable firmware on the unit; photograph edge connector pin labeling and document factory default thermocouple cold-junction configuration for commissioning reference.
- Final QC & Packaging: Wipe PCB surfaces with anti-static cloth; place the unit in foam-lined static shielding bag, attach a QC Passed label printed with inspection date before sealing in original factory carton.
Replacement Pitfall Guide
❗Firmware Mismatch Risk: Older Freelance CPU firmware revisions lack register support for built-in cold-junction compensation. New board insertion triggers constant temperature offset faults. Mitigation: Flash controller firmware to v4.10 or newer before rack installation.❗DIP Switch / Jumper Misconfiguration: The board ships factory-set for thermocouple inputs. RTD sensor wiring with unadjusted jumpers yields flat, unchanging temperature readings. Mitigation: Photograph jumper positions on the old unit and reconfigure each channel’s signal type jumpers before connecting field probes.❗Terminal / Cable Incompatibility: 4–20 mA DAI01 trunk cables omit dedicated RTD excitation return pins matched to the unit’s front-end. Forced insertion scratches delicate precision signal PCB traces. Mitigation: Deploy only OEM multi-type sensor trunk cables with full mV/RTD/TC pinout mapping.❗Power Supply Mismatch: A single DPW03 48 W auxiliary supply cannot feed a fully populated DRA02 rack holding multiple of these boards. Combined continuous draw exceeds the 2 A output limit. Mitigation: Pair racks with DPW01 120 W power supplies, maintain 20 % current headroom for peak ADC sampling loads.❗ESD Damage: Dry winter control room air generates static discharge to exposed edge connector pins. Field records show ungrounded handling corrupts ADC reference circuits, creating permanent uncorrectable measurement drift; full rack downtime labor costs exceed $1,400. Mitigation: Use an anti-static mat under the rack chassis and hold bare cabinet ground metal for three full seconds before seating the card into the backplane.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
Compatibility Matrix
- → DAI01 : Needs Adaptation — DAI01 only supports 4–20 mA current loops, all thermal sensor loops require external signal conditioning boards
- Freelance 2000 CPU + Rack : Direct — native Freelance backplane register mapping, no software edits needed for thermal scaling
- S100 MasterPiece 200 Safety Racks : Incompatible — different parallel backplane bus pin assignment and communication protocol
- 3-wire Pt100 furnace temperature probes : Direct — factory jumper configuration supports standard industrial thermal sensor wiring
- AC800M S800 I/O racks : Incompatible — Profibus fieldbus cannot interface with Freelance internal rack bus
