Product Overview

The ABB 3BHB002953R0117​ is a scaling board​ in ABB’s Procontrol P14 distributed control system — the legacy DCS platform ABB deployed across thermal power, hydro, gas-turbine auxiliaries, and large-process plants from the mid-1990s through the Advant OCS transition. In a P14 I/O Station rack (the local panel that terminates field signals — AI, AO, DI, DO, PI — and talks to the P14 Process Station in the MCR over the Procontrol bus), the analog input path is split across two functional pieces: the P14 AI module​ (e.g., the 8-channel 0–20 mA / ±10 V A/D card, 3BHB002945 class) does the hardware conversion, and the ABB 3BHB002953R0117​ scaling board sits adjacent — either as a piggyback daughter on the AI module or as a separate slot-level board in the same I/O rack, depending on the P14 sub-revision — and applies the per-channel gain, offset, and linearisation so that the raw A/D counts reaching the UFC719AE01 Station Processor​ (the I/O rack’s scan brain, covered two entries earlier) are already mapped into engineering-unit integers (e.g., 0–10000 = 4–20 mA = 0–10 bar for a pressure transmitter). The ABB 3BHB002953R0117​ is therefore not a standalone field device — it is meaningless outside a P14 I/O rack with P14 AI modules and a UFC719AE01 — but inside that chain it is the piece that makes “raw counts” into “bar / °C / kW” without the Process Station doing the math every scan.Physically, the ABB 3BHB002953R0117​ follows the P14 Eurocard form factor (6U height, ~160 mm depth, single-wide in the P14 I/O rack guide rails), seats into the P14 rack backplane (2-row DIN header + guide rails), and draws from the rack’s 5 V DC (logic) + 24 V DC (aux) backplane power — same as the UFC719AE01 and the P14 AI/AO/DI/DO modules it shares the rack with. The board carries precision metal-film gain resistors (sometimes DIP-switch selectable per channel for common ranges like 4–20 mA / ±10 V / 0–10 V / PT100, depending on the AI front-end it’s paired with), and on later sub-revs an EEPROM or PGA (programmable gain amplifier) controlled by the Station Processor over the rack bus — the ABB 3BHB002953R0117​ doesn’t have a local CPU, it’s a coprocessor peripheral that the UFC719AE01 configures at rack init and then leaves alone during cyclic scan. For maintenance teams on P14 plants (many 1990s–2000s coal/gas/hydro units still on P14 because “it works”), the ABB 3BHB002953R0117​ is a B-class spare: when a P14 AI channel reads “flat 0” or “full scale 10000” but the field transmitter is healthy (4–20 mA confirmed at the marshalling block), the fault is often the ABB 3BHB002953R0117​ gain/resistor drifting or the PGA register corrupted — swapping the board (keep the AI module’s field wiring on the P14 TB) restores the channel in minutes. The ABB 3BHB002953R0117​ also appears in MRO BOMs alongside the UFC719AE01 and the P14 AI modules as the “keep the analog rack alive” set — all three are OEM-discontinued but available through ABB legacy channel and verified-pull/refurb stock.

Technical Specifications

Main Features and Advantages

Gain+offset per P14 AI channel without Process Station load:The core job of the ABB 3BHB002953R0117​ is to offload math from the P14 Process Station. A P14 AI module’s A/D outputs raw counts (e.g., 0–4095 for 12-bit, 0–16383 for 14-bit depending on the AI front-end). Without the ABB 3BHB002953R0117, the UFC719AE01 Station Processor would have to multiply every channel every scan: (counts - offset) × gain → engineering units. With the ABB 3BHB002953R0117​ doing the scaling in hardware (resistor divider + op-amp, or PGA + EEPROM), the Station Processor reads pre-scaled integers (e.g., 0–10000 = 0–10 bar) and just buffers them to the Process Station over the Procontrol bus. On a P14 I/O rack with 4× AI cards (32 analog points — typical for a boiler-deck BMS rack: 8× burner pressure, 8× FD fan damper position, 8× FD fan outlet pressure, 8× PA fan status-analog), the ABB 3BHB002953R0117​ (or 4× of them, one per AI) saves the Station Processor ~128 multiply-adds per scan — negligible on a 68xxx-class MPU, but the architectural point is: the scaling lives with the I/O, not with the CPU. That’s the P14 “distributed intelligence” philosophy, and the ABB 3BHB002953R0117​ is the hardware that carries it for analog.Range adaptability via gain resistors / PGA:Early P14 sub-revs of the ABB 3BHB002953R0117​ used precision metal-film DIP-selectable gain resistors — a bank of 8 DIP switches per channel (or per pair) let the panel builder select the range to match the field transmitter: 4–20 mA → 0–10000, ±10 V → -10000/+10000, 0–10 V → 0–10000, PT100 (via an AI XTR front-end) → 0–10000 = 0–400 °C, etc. Later sub-revs (closer to the R0117 rev) moved to a PGA + EEPROM approach: the UFC719AE01 writes the gain/offset registers to the ABB 3BHB002953R0117​ at rack init (values sourced from the P14 engineering tool / Process Station download), and the ABB 3BHB002953R0117​ holds them in EEPROM across power cycles. Either way, the plant doesn’t need different AI hardware for different transmitter ranges — one P14 AI + one ABB 3BHB002953R0117​ covers pressure (4–20 mA), position (±10 V), temperature (PT100 XTR), all via scaling config. For spare-parts buyers, this means one ABB 3BHB002953R0117​ spare covers all analog ranges in the plant’s P14 I/O racks — no “pressure-scaling” vs “position-scaling” SKU split.Paired with UFC719AE01 Station Processor in the same rack:The ABB 3BHB002953R0117​ is not a peer of the UFC719AE01 — it’s a subordinate. The UFC719AE01 scans the P14 AI modules over the rack bus, reads the raw counts, passes them through the ABB 3BHB002953R0117​ scaling path (or the ABB 3BHB002953R0117​ scales in-line before the counts reach the UFC719AE01, sub-rev dependent), and the UFC719AE01 then buffers the scaled integers into NVRAM for the Process Station. When troubleshooting a “P14 AI channel stuck at 0” ticket: Step 1, check the field transmitter (4–20 mA at marshalling?). Step 2, check the P14 AI module’s front LED (power/error). Step 3, if AI module is healthy and the field is healthy, the ABB 3BHB002953R0117​ gain/resistor or PGA reg is the suspect. Swapping the ABB 3BHB002953R0117​ (keep the AI module’s TB wired — the ABB 3BHB002953R0117​ is on the rack backplane, not on the TB) restores the channel. The UFC719AE01 re-inits the ABB 3BHB002953R0117​ at next rack scan (downloads the gain/offset from NVRAM / Process Station), no re-keying needed. That “wire-once, swap-module, auto-reinit” story is consistent across the P14 I/O rack family (UFC719AE01, P14 AI, ABB 3BHB002953R0117, P14 DI/DO) — ABB designed the P14 rack for hot-swap per-module, though in practice most plants kill the rack PSU for a swap to be safe.