Technical Specification

General:

• Function: NMEA 0183 Buffer / Splitter / Expander / Amplifier
• Purpose: To distribute NMEA 0183 data from a single talker to multiple listeners with isolation.

NMEA 0183 Ports:

• Inputs:
  • Number: Typically 1 (one) NMEA 0183 Input.
  • Type: Optically isolated (galvanic isolation between input and internal circuitry/outputs).
  • Compatibility: RS-422, RS-232, and TTL level NMEA 0183 data.
  • Baud Rates Supported: Auto-detecting or user-selectable, commonly supporting 4800, 9600, 19200, 38400 bps.
• Outputs:
  • Number: 6 (six) NMEA 0183 Outputs (this is implied by the “-08” in the model name and common configurations for S4391).
  • Type: Each output is independently optically isolated (galvanic isolation between outputs and from input).
  • Drive Capability: Capable of driving multiple NMEA 0183 listeners per output (typically 1-4 standard NMEA loads per output, depending on specific output buffer strength).
  • Compatibility: RS-422 (differential) and/or RS-232 (single-ended) compatible output.

Electrical:

• Power Input:
  • Voltage Range: 10 VDC to 32 VDC (some units specify 22-36V DC, but a wider range is more common for modern marine electronics).
  • Current Consumption: Typically low, in the range of 50 mA to 150 mA (depending on load and activity).
  • Protection:
    • Reverse Polarity Protection.
    • Over-current protection (internal fuse or self-resetting).
    • Transient voltage suppression (TVS) for surge protection.
• Isolation:
  • Input Isolation: >1500 VDC (between input and power/outputs).
  • Output Isolation: >1500 VDC (between each output and power/other outputs).
  • Ground Isolation: Prevents common mode noise and ground loops.

Performance:

• Data Latency: Minimal, typically <10 ms (negligible for NMEA 0183 applications).
• Data Rate: Capable of handling standard NMEA 0183 sentence rates without loss.

Environmental:

• Operating Temperature: -15°C to +55°C (5°F to 131°F).
• Storage Temperature: -20°C to +70°C (-4°F to 158°F).
• Humidity: 0-95% non-condensing.
• Enclosure Rating: Typically IP65 or IP66 (Dust-tight and protected against water jets/strong water jets, suitable for exposed marine environments or inside helm stations).
• Mounting: Bulkhead or surface mount.

Physical:

• Dimensions: Varies but typically compact, e.g., 120mm x 80mm x 40mm (L x W x H) or similar.
• Weight: Light, typically less than 0.5 kg.
• Connections: Screw terminals for power and NMEA input/outputs.

Indicators:

• Power LED: To indicate power supply status.
• Data LEDs: May include LEDs for input data activity.

Compliance:

• CE Mark (European conformity).
• RoHS (Restriction of Hazardous Substances).
• Relevant marine standards (e.g., IEC 60945 for maritime navigation and radiocommunication equipment and systems).