Kulite RDD Long-Distance Digital Display

Overview

The Kulite RDD (Remote Digital Display) is a rugged, industrial-grade digital display unit engineered for reliable long-distance readout of analog and digital sensor signals—specifically optimized for integration with Kulite and Honeywell piezoresistive pressure transducers. Unlike standard local-mount displays, the RDD employs RS-232 serial communication to receive conditioned sensor output at distances up to 50 feet (15.2 m), eliminating signal degradation commonly associated with analog voltage or current transmission over extended cable runs. Its architecture follows a deterministic serial protocol with fixed baud rate (typically 9600 bps), parity, and framing—ensuring bit-level integrity in electrically noisy manufacturing and test environments. Designed for permanent installation in control rooms, test benches, and calibration labs, the RDD serves as a dedicated human-machine interface (HMI) that decouples sensor mounting location from operator visibility requirements—critical in high-temperature, high-vibration, or hazardous-area applications where direct access to transducers is impractical.

Key Features

• RS-232 input compatibility with standard 9-pin D-sub connector (DB9 male), compliant with EIA/TIA-232-F electrical specifications
• Supports direct connection to PLCs, data acquisition systems, and Windows/Linux-based PCs via standard serial interface
• Factory-supplied shielded twisted-pair cable assembly minimizes EMI susceptibility and eliminates field termination errors
• Configurable mounting options: panel-mount (front bezel flange) and platform-mount (rear DIN-rail or bracket-compatible)
• LED-based 6-digit numeric display with high-brightness red or green segments (selectable at order), rated for >100,000-hour operational life
• Operating temperature range: –20 °C to +70 °C; IP65-rated front bezel for dust and low-pressure water resistance

Sample Compatibility & Compliance

The RDD is validated for use with Kulite XTEL, XTE, and Q Series pressure transducers, as well as select Honeywell ST3000 and MPX series sensors outputting RS-232 ASCII-formatted data packets (e.g., “P=123.45 PSIrn”). It does not perform signal conditioning, scaling, or linearization—the host sensor must deliver fully processed, calibrated digital values. The unit complies with FCC Part 15 Class A emissions limits and meets CE marking requirements under the EMC Directive 2014/30/EU. While not intrinsically safe, it may be deployed in non-classified areas adjacent to Class I Div 2 zones when installed per NEC Article 501 guidelines. Documentation includes RoHS 2011/65/EU and REACH SVHC declarations.

Software & Data Management

The RDD operates autonomously without host software—it is a display-only device with no onboard memory, logging capability, or network connectivity. All configuration (e.g., display units, decimal places, update rate) is performed at the sensor level or via external controller firmware. However, its RS-232 interface enables seamless integration into SCADA and LabVIEW-based DAQ systems using standard VISA or Modbus RTU-to-ASCII gateways. When used with FDA-regulated processes (e.g., pharmaceutical pressure monitoring), the RDD itself falls outside 21 CFR Part 11 scope since it neither stores nor modifies data—but audit trails must originate upstream at the sensor or DAQ layer to satisfy GLP/GMP traceability requirements.

Applications

• Static and dynamic pressure monitoring in aerospace hydraulic test stands, where transducers are mounted inside sealed manifolds and displays reside outside containment
• Process validation in bioreactor and autoclave systems requiring real-time pressure feedback at operator consoles located >10 m from vessel ports
• Calibration laboratories performing ISO/IEC 17025-compliant pressure verification, where separation between reference standard and UUT reduces thermal coupling error
• Automotive brake line and fuel rail testing rigs integrating legacy Honeywell transducers with modern PLC-based control logic
• Research facilities utilizing Kulite high-temperature sensors (>500 °C) in combustion chambers, with RDD units installed in climate-controlled observation rooms

FAQ

Does the RDD support RS-485 or USB interfaces?
No—the RDD is RS-232 only. Conversion to RS-485 or USB requires an externally certified protocol converter placed between the sensor and display.
Can the display update rate be adjusted?
No—the refresh interval is fixed at 250 ms (4 Hz) and synchronized to incoming packet timing from the sensor.
Is custom scaling or engineering unit conversion possible on the RDD?
No—scaling must be applied at the sensor firmware or upstream controller level prior to RS-232 transmission.
What is the maximum allowable cable length beyond 50 feet?
While RS-232 spec defines 50 ft at 19.2 kbps, the RDD’s conservative 9600 bps implementation permits up to 100 ft with low-capacitance cable (e.g., Belden 9841); however, signal integrity validation is required per site-specific EMI conditions.
Does Kulite provide calibration certificates for the RDD?
No—the RDD is a passive display device with no metrological transfer function; calibration applies solely to the connected pressure transducer per ISO 9001 or ANSI/NCSL Z540-1.