DCbox Signal Transmitter XTP-P-21-Q-A | 4–20mA Marine Signal Transmitter

Item Code:

DC BOX SIGNAL TRANSMITTER

Brand:

Taiwan

Condition:

New product

Manufacturer

DCbox

Country of Origin

Taiwan

Product Type

Analog Signal Transmitter / Signal Conditioner

Marine Application

Marine Automation, Engine Monitoring & Process Control Systems

DCbox Signal Transmitter XTP-P-21-Q-A

Product Introduction

The DCbox Signal Transmitter Model XTP-P-21-Q-A is a compact industrial and marine signal transmitter designed to convert sensor input signals into a stable 4–20 mA analog output, making it suitable for PLCs, engine monitoring systems, alarm panels, and marine automation equipment.

According to the product label:

Model: XTP-P-21-Q-A
Input: 0–100% (Excitation 2.5 V)
Output: 4–20 mA DC
Power Supply: AC/DC 18–60 V
Manufactured in Taiwan

Its adjustable SPAN and ZERO controls allow precise calibration for accurate signal transmission in demanding marine environments.

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What Is This Equipment?

A signal transmitter converts a sensor's electrical signal into the industry-standard 4–20 mA current loop, ensuring reliable long-distance signal transmission with minimal interference.

The DCbox XTP-P-21-Q-A is commonly used to interface field instruments with:

PLC systems
Engine Monitoring Systems (EMS)
Alarm & Monitoring Systems
Automation Controllers
SCADA Systems
Marine Control Panels

This ensures stable and accurate process measurements throughout the vessel.

Main Features

Standard 4–20 mA analog output
Wide AC/DC 18–60 V power supply
Adjustable Zero and Span calibration
Compact panel-mount design
High signal accuracy
Excellent noise immunity
Reliable continuous operation
Suitable for marine and industrial environments
Easy installation and maintenance
Long service life

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Main Components

The DCbox Signal Transmitter typically consists of:

Analog Signal Processing Circuit
Input Terminal Block
Output Terminal Block
Power Supply Circuit
Zero Adjustment Potentiometer
Span Adjustment Potentiometer
Isolation Circuit
Protective Housing
Mounting Base
Identification Label

Marine Applications

The DCbox Signal Transmitter is widely used onboard:

Engine Monitoring Systems
Main Engine Control Systems
Auxiliary Engine Monitoring
Boiler Automation
Fuel Oil Systems
Lubricating Oil Systems
Cooling Water Systems
Tank Level Monitoring
Pressure Monitoring
Temperature Monitoring
Pump Monitoring Systems
Ballast Control Systems
Cargo Monitoring Systems
Marine PLC Panels
Offshore Platforms

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Common Problems & Troubleshooting

Problem	Possible Cause	Recommended Solution
No output signal	Power supply failure	Check AC/DC supply voltage
Incorrect 4–20 mA output	Calibration drift	Adjust Zero and Span
Unstable output	Loose wiring	Tighten terminal connections
Signal noise	Improper grounding	Verify grounding and shielding
PLC reading error	Incorrect wiring	Check input/output terminal configuration
Output fixed at 4 mA or 20 mA	Sensor or transmitter fault	Inspect sensor and replace transmitter if necessary

Maintenance Tips

For long-term reliability:

Inspect wiring terminals periodically.
Verify power supply voltage.
Check output calibration during routine maintenance.
Keep the transmitter dry and free from dust.
Inspect for corrosion in marine environments.
Confirm proper grounding and cable shielding.
Replace damaged wiring immediately.

Why Ships Still Use DCbox Signal Transmitters

Marine automation systems rely heavily on standardized 4–20 mA communication, making signal transmitters essential for accurate process monitoring.

The DCbox XTP-P-21-Q-A continues to be widely used because it offers:

Reliable analog signal conversion
Stable long-distance transmission
Simple calibration
High compatibility with PLC and DCS systems
Low maintenance requirements
Robust construction for continuous operation

These advantages make it an excellent choice for commercial ships, offshore installations, and industrial process plants.

Frequently Asked Questions (FAQ)

What is the function of the DCbox Signal Transmitter?

It converts field sensor signals into a standard 4–20 mA analog output for monitoring and control systems.

What power supply does it require?

The XTP-P-21-Q-A operates on AC/DC 18–60 V.

What is the output signal?

The transmitter provides a 4–20 mA DC output.

Can Zero and Span be adjusted?

Yes. The front panel includes dedicated ZERO and SPAN adjustment controls for calibration.

Is it suitable for marine applications?

Yes. It is commonly used in marine automation, engine monitoring, boiler control, and process instrumentation systems.

Short Product Description

The DCbox Signal Transmitter XTP-P-21-Q-A is a precision analog signal transmitter manufactured in Taiwan. Designed for marine and industrial automation, it converts field instrument signals into a stable 4–20 mA output, ensuring accurate communication between sensors and monitoring systems. Its wide power input, easy calibration, and reliable performance make it an ideal solution for shipboard automation and engine control applications.

SM MARINE SERVICE™

Marine Automation & Navigation Equipment Supplier

Available Condition

New Equipment
Used Equipment
Refurbished Equipment
Reconditioned Equipment

Stock Location

Bangladesh
China

Services

Worldwide Shipping
Technical Support
Spare Parts Supply
Marine Equipment Sourcing

Contact Information

SM MARINE SERVICE™
Samir Market, DT Road, Pahartali, beside CDA Market, Chattogram, Bangladesh

Mobile / WhatsApp / Viber: +88 01818 929292

Email: info@smmarineservice.com

Website: www.smmarineservice.com