YOKOGAWA F9328QM-02 Signal Processing PCB Card – YEWFLO Series

YOKOGAWA F9328QM-02 YEWFLO Vortex Flowmeter Signal Processing PCB Card — Core Intelligence of the Transmitter Assembly

The YOKOGAWA F9328QM-02 is the OEM signal processing printed circuit board assembly (PCBA) engineered exclusively for the YOKOGAWA YEWFLO series vortex flowmeter transmitter. Within the YEWFLO architecture, this card occupies the position of primary signal conditioner: it receives raw piezoelectric or capacitive vortex-shedding impulses from the sensor element, applies multi-stage analog filtering, executes frequency-to-digital conversion, and drives the transmitter’s output stage — whether 4–20 mA HART, pulse, or digital fieldbus. Without a fully functional F9328QM-02, the transmitter cannot produce a calibrated flow signal regardless of the mechanical integrity of the flowtube body. This makes the board a single-point-of-failure component in any YEWFLO-based flow loop, and its availability as a verified spare is operationally critical for process plants running continuous production schedules.

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Technical Parameters

Hardware Logical Analysis

The F9328QM-02 implements a multi-stage signal chain designed to extract reliable frequency data from the inherently noisy vortex-shedding environment. The front-end analog section employs a differential charge amplifier topology to interface with the piezoelectric sensor element. This configuration provides high common-mode rejection ratio (CMRR), which is essential in industrial installations where ground loops and conducted interference from variable-frequency drives (VFDs) or high-current switching loads can corrupt low-amplitude sensor signals in the 1–3,000 Hz vortex frequency band.

Following the charge amplifier stage, the signal passes through an active bandpass filter network. The filter’s center frequency and Q-factor are matched to the expected vortex shedding frequency range for the specific flowtube geometry, suppressing both sub-Hz mechanical vibration artifacts and high-frequency EMI pickup above the measurement band. This is a critical design decision: a poorly tuned filter at this stage would either alias vibration noise into the flow count or attenuate genuine vortex events at low flow velocities, degrading rangeability at the low end of the meter’s specified turndown ratio.

The conditioned analog signal feeds into a precision zero-crossing detector and frequency counter implemented in the board’s digital logic section. The counter accumulates vortex events over a configurable gate time, producing a stable frequency word that is then linearized against the meter’s K-factor (stored in non-volatile EEPROM on the board) to yield a volumetric flow rate. The EEPROM also retains the transmitter’s calibration coefficients, tag name, and engineering unit configuration — meaning an F9328QM-02 replacement preserves the original calibration without requiring a full re-characterization of the flowtube, provided the replacement board is loaded with the correct configuration file via HART communicator or YOKOGAWA FieldMate.

The output drive section generates the 4–20 mA loop current with a resolution of better than 0.1 µA, corresponding to a digital-to-analog conversion depth sufficient to represent the full 0–100% flow span with sub-0.01% FS incremental steps. The HART modem circuit superimposes the FSK communication signal (1,200 Hz / 2,200 Hz) onto the 4–20 mA loop at a modulation depth compliant with HART Physical Layer Specification revision 7. The board’s EMC design incorporates transient suppression diodes (TVS) on all external-facing signal lines, ferrite bead filtering on the power supply rails, and a ground plane partition that isolates the analog signal ground from the digital logic ground, preventing digital switching noise from coupling into the measurement path.

System Integration Benefits

• Calibration Retention on Board Swap: The F9328QM-02 stores K-factor, zero/span trim, and tag configuration in onboard EEPROM. A direct replacement restores full transmitter function without flowtube recalibration, reducing maintenance window duration from hours to minutes.
• Deterministic HART Response Time: The board’s HART stack implementation delivers command response times within the 2-response-preamble minimum specified by HART revision 7, ensuring compatibility with asset management systems (AMS, PACTware, FieldMate) that rely on polling-cycle determinism for device health monitoring.
• Diagnostic Transparency via HART DD: The board exposes device variables including sensor amplitude, signal-to-noise ratio of the vortex signal, board temperature, and output saturation flags through HART Device Description (DD) commands 48 and 33. This allows the DCS or AMS to detect degrading sensor performance before a measurement failure occurs.
• Low-Flow Cutoff Configurability: The digital processing section implements a programmable low-flow cutoff threshold (expressed as a percentage of URL) that forces the 4–20 mA output to 4 mA when flow falls below the threshold, preventing false low-flow readings from vibration-induced noise at near-zero velocities.
• Fail-Safe Output Mode: The board supports configurable fail-safe output direction (upscale / downscale / hold last value) in the event of sensor signal loss or internal diagnostic fault, allowing the DCS to implement appropriate process response logic without ambiguity.
• Surge and Transient Protection: TVS diode arrays on the loop terminals provide protection against IEC 61000-4-5 Level 3 surge events (1 kV line-to-earth), protecting the board in installations where lightning-induced transients on cable runs are a documented risk.
• Wide Supply Voltage Tolerance: The board operates across a 10.5–42 V DC loop supply range, accommodating both 24 V DC standard instrument loops and legacy 48 V DC systems without requiring external regulators or loop isolators.
• OEM Connector Compatibility: All board-to-transmitter connectors are OEM-matched to YOKOGAWA YEWFLO transmitter housing pinouts, eliminating the risk of mis-wiring during field replacement and ensuring mechanical retention force meets YOKOGAWA’s vibration specification for the transmitter assembly.

Quality Assurance & Global Logistics

Every F9328QM-02 unit supplied by siemensplc.com is sourced through verified industrial distribution channels with full traceability to YOKOGAWA OEM production. Units are inspected upon receipt against the following criteria: PCB surface condition (no delamination, lifted pads, or solder bridging), component population completeness against YOKOGAWA BOM reference, label and date-code verification, and connector pin integrity. Units that do not pass inspection are quarantined and not listed for sale.

Packaging follows ESD-safe protocols: each board is placed in a conductive foam tray inside an anti-static shielding bag, sealed with a humidity indicator card, and packed in a rigid corrugated carton with foam corner protection. This packaging standard is designed to survive international air freight handling without mechanical or electrostatic damage to the PCB assembly.

Shipments originate from our warehouse in Xiamen, China. Standard international delivery is via DHL Express or FedEx International Priority, with typical transit times of 3–5 business days to major industrial hubs in Europe, Southeast Asia, the Middle East, and the Americas. For shutdown-critical orders, same-day dispatch is available for orders confirmed before 14:00 CST. Export documentation including commercial invoice, packing list, and certificate of conformance is provided with every shipment. HS code classification and customs value declaration are handled accurately to avoid clearance delays at destination ports.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
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