Gilbarco Dispenser Twowire Protocol For Third Party Pump Controllers New May 2026

The Gilbarco Two-Wire protocol is a proprietary serial communication standard used to connect fuel dispensers to point-of-sale (POS) systems and fuel site controllers

. For third-party controller developers, mastering this protocol requires understanding its physical current loop interface and its multi-drop messaging structure. www.mchip.net Physical Layer: 2-Wire Current Loop

Unlike standard RS-232 or RS-485, the Gilbarco protocol traditionally operates on a 2-wire current loop Levtech Service & Production

Requires unshielded twisted pair (UTP) cable with 10–12 twists per foot. Isolation:

To prevent equipment damage, third-party interfaces must use optical isolation between the dispenser data lines and the controller. Active vs. Passive:

The site controller typically acts as the "active" unit, providing the current for the loop. Communication Parameters

Third-party controllers must match these specific serial settings to establish a handshake with Gilbarco dispensers: 4-20mA Comunications - All About Circuits Forum

The Gilbarco Two-Wire protocol is a specialized communication standard used to interface third-party fuel pump controllers (like POS systems and forecourt controllers) with Gilbarco dispensers. It primarily operates on a 45mA current loop interface. Core Protocol Specifications

The protocol is typically divided into variants based on the specific dispenser model and baud rate requirements: Baud Rates:

4800 bps: Standard for Highline-2, Euroline, and Euro Dimension models.

5787 bps: Often referred to as "Corporate baudrate," used for Highline-111 and newer international models. Data Framing: 8 Data bits, Even Parity, and 1 Stop bit.

Protocol Efficiency: Uses a small number of characters to maintain high-speed communication between the controller and the pump. Hardware & Wiring Requirements

Integrating third-party controllers requires specific physical infrastructure to handle the current loop signals: The Gilbarco Two-Wire protocol is a proprietary serial

Wiring: Use Unshielded Twisted Pair (UTP) with 10–12 twists per foot. Shielded wire is strictly prohibited.

Gauge: Minimum 18 AWG for runs up to 1000 feet; 14 AWG for runs up to 2600 feet.

Isolation: Third-party interface converters, such as those from Levtech or Technotrade, often feature optical isolation to protect the controller from voltage spikes on the pump loop. Implementation Tools

For developers building or troubleshooting third-party controllers, several kits and simulators are available: RS-232 to Two-Wire Converter Box Kit

Gilbarco Dispenser Two-Wire Protocol for Third-Party Pump Controllers: A New Era of Compatibility and Efficiency

The fuel retailing industry has witnessed significant advancements in recent years, with a growing emphasis on interoperability, efficiency, and customer experience. One crucial aspect of this evolution is the communication protocol used between dispensers and pump controllers. Gilbarco, a leading provider of fuel dispenser solutions, has introduced a new two-wire protocol for third-party pump controllers, revolutionizing the way fuel retailers manage their dispensers. In this article, we will explore the Gilbarco dispenser two-wire protocol, its benefits, and the implications for the fuel retailing industry.

Background: The Need for Interoperability

Fuel retailers use dispensers from various manufacturers, and often, these dispensers need to communicate with pump controllers from different vendors. The lack of a standardized communication protocol has led to compatibility issues, increased costs, and complexity in system integration. To address this challenge, Gilbarco has developed a two-wire protocol that enables seamless communication between Gilbarco dispensers and third-party pump controllers.

Gilbarco Dispenser Two-Wire Protocol: An Overview

The Gilbarco dispenser two-wire protocol is a communication standard that allows Gilbarco dispensers to communicate with third-party pump controllers over a simple, two-wire connection. This protocol enables the exchange of vital information, such as fuel authorization, transaction data, and dispenser status, between the dispenser and the pump controller.

Key Features and Benefits

The Gilbarco dispenser two-wire protocol offers several key features and benefits, including: Simplified Integration : The two-wire protocol reduces the

  1. Simplified Integration: The two-wire protocol reduces the complexity and cost of integrating Gilbarco dispensers with third-party pump controllers.
  2. Interoperability: The protocol enables seamless communication between Gilbarco dispensers and pump controllers from different manufacturers, promoting a more open and competitive market.
  3. Increased Efficiency: The two-wire protocol streamlines data exchange, reducing the need for complex software development and minimizing the risk of communication errors.
  4. Enhanced Security: The protocol supports secure authentication and authorization, ensuring that only authorized transactions are processed.
  5. Flexibility: The two-wire protocol is designed to accommodate future updates and expansions, providing a flexible solution for evolving fuel retailing needs.

Technical Details

The Gilbarco dispenser two-wire protocol is based on a master-slave architecture, with the pump controller acting as the master and the dispenser as the slave. The protocol uses a simple, ASCII-based command structure, allowing for easy implementation and debugging.

The two-wire connection uses a standard RS-485 interface, which provides a reliable and robust communication link between the dispenser and the pump controller. The protocol supports data transmission rates of up to 19200 bps, ensuring fast and efficient communication.

Implications for the Fuel Retailing Industry

The Gilbarco dispenser two-wire protocol has significant implications for the fuel retailing industry. By promoting interoperability and reducing integration complexity, the protocol:

  1. Increases Competition: The two-wire protocol opens the market to more players, fostering competition and driving innovation in fuel retailing.
  2. Reduces Costs: The simplified integration process reduces costs for fuel retailers, allowing them to allocate resources more efficiently.
  3. Enhances Customer Experience: The protocol enables faster, more reliable transactions, contributing to a better customer experience.

Conclusion

The Gilbarco dispenser two-wire protocol represents a major breakthrough in fuel retailing technology, enabling seamless communication between Gilbarco dispensers and third-party pump controllers. By promoting interoperability, efficiency, and security, the protocol sets a new standard for the industry, driving innovation and competition. As the fuel retailing landscape continues to evolve, the Gilbarco dispenser two-wire protocol is poised to play a key role in shaping the future of the industry.

Understanding the Gilbarco Dispenser Two-Wire Protocol The Gilbarco Two-Wire Protocol is a proprietary communication standard used to interface Gilbarco fuel dispensers with Point-of-Sale (POS) systems and third-party pump controllers. It operates on a current loop principle, traditionally at 45 mA, although variants like 20 mA or 60 mA may be encountered depending on the specific hardware. Core Technical Specifications

To successfully integrate a third-party controller, the following physical and logical parameters are standard:

Baud Rate: Typically 5787 bps, though some configurations may use 4800 bps. Data Format: 8 Data bits, Even Parity, and 1 Stop bit.

Logical Structure: Uses an 11-bit data format for maximum throughput.

Topology: A multi-drop loop supporting up to 16 fueling positions on a single pair of wires. Communication Model Authorize hose (product

The protocol follows a Master-Slave architecture. The pump controller (Master) initiates all communication by polling the dispensers (Slaves). Every unit on the loop receives the data, but only the specific unit addressed responds, while others ignore the message. Interface Requirements for Third-Party Systems

Connecting a standard PC or a modern PLC to a Gilbarco dispenser often requires an interface converter to bridge the gap between RS-232/USB/RS-485 and the 2-wire current loop.

Isolation: Optical isolation is highly recommended for safety and to prevent electrical noise from the forecourt from damaging the POS system. Converters: Products like the Levtech Communication Interface or the Technotrade PTS-U3 Controller are specifically designed to handle these conversions.

Command Set: Third-party developers must implement commands for bringing a pump online, configuring it, polling for status, and managing fuel sale data. Modern Upgrades

For newer installations, Gilbarco has introduced high-speed communication technologies like the Invenco Link

, which allows for Ethernet-over-2-wire communication, enabling advanced features like EMV payment without requiring new underground wiring. RS-232 to Two-Wire Converter Box Kit

Here are the key features of the Gilbarco Two-Wire Protocol (often referred to as G-Site or TLS-2 over serial) when used with third-party pump controllers for new installations:

4. Standardized Message Set (Gilbarco "G-Site" Format)

  • Supports:
    • Authorize hose (product, preset limit)
    • Sale start/stop
    • Real-time volume & price readback
    • Pump reset / clear sale
    • Status of nozzle, door, meter, emergency stop

3. Integration Requirements for Third-Party Controllers

For a new third-party controller to successfully operate Gilbarco dispensers via the Two-Wire Protocol, the following integration points must be addressed:

2. Technical Overview

2.1 What is the Two-Wire Protocol?

The "Two-Wire" interface is a proprietary serial communication protocol developed by Gilbarco (now part of Vontier/Dover Fueling Solutions). It allows a single Forecourt Controller to manage multiple dispensers (pumps) over a daisy-chain or multi-drop cabling infrastructure.

Handshaking (The New Logic):

Historically, a third-party controller had to mimic Gilbarco’s "polling" (asking each dispenser 10x per second). The new converters handle this polling internally. Your controller simply sends a command string:

*04P12000L

Breakdown: Start (*), Address (04), Preset (P), 2000 (cents), Stop (L).

The converter then translates this into the two-wire current loop pulse train. Within 50ms, the Gilbarco dispenser activates the relay for that hose.