Third-party controllers rarely connect directly to the raw current loop. Instead, they interface via a or an isolation card. The D-Box translates standard RS-232, RS-485, or USB signals from your controller into the high-voltage/current-loop physical signals required by the dispenser's electronic head. 2. Protocol Architecture: Master-Slave Polling
Variable length; contains parameters like preset amounts, grade selections, or unit prices.
To successfully integrate a third-party controller, the following components are typically required:
Unlocking Forecourt Automation: The Gilbarco Dispenser Two-Wire Protocol for Third-Party Pump Controllers
Integrating allows station operators to bypass vendor lock-in, maximize the lifespan of legacy assets like the Gilbarco Legacy series, and seamlessly deploy new dispensers like the Gilbarco Encore 500 alongside alternative forecourt hardware. 1. What is the Gilbarco Two-Wire Protocol? Third-party controllers rarely connect directly to the raw
Build a deterministic, non-blocking asynchronous software loop to handle polling within the .
When developing a new Pump Controller, the following workflow is recommended:
Before authorization, the controller sends unit prices for each product grade and applies presets if the customer opted for a specific monetary or volume limit.
Several cloud-based controllers (e.g., PDI’s FueLink, Kalibrate Edge) now offer two-wire via an IoT gateway that uses an on-board current-loop interface. using an STM32 MCU
Controller approved the sale, dispenser preparing to pump.
For developers building or troubleshooting third-party controllers, several kits and simulators are available: RS-232 to Two-Wire Converter Box Kit
The controller sends a "Poll" command to a specific address. If the pump has a status change (e.g., nozzle lifted), it responds with the relevant data packet.
[State: Idle] -> Poll Pump -> If Nozzle Lifted -> [State: Calling] [State: Calling] -> Send Prices/Presets -> Send Authorize -> [State: Fueling] [State: Fueling] -> Poll Totals Real-Time -> If Nozzle Returned -> [State: Ended] [State: Ended] -> Read Final Transaction Data -> Send Clear/Acknowledge -> [State: Idle] 6. Challenges and Compliance When developing a new Pump Controller
They allow operators to upgrade their site management system without replacing functioning dispensers. 3. Implementing the Protocol with New Controllers (2026)
When engineering a custom embedded system (e.g., using an STM32 MCU, ESP32, or industrial PC) to communicate via the Gilbarco protocol, standard RS-232/RS-485 transceiver ICs will not work natively. Hardware Interface Requirements
During and after fueling, the controller requests the current transaction data. The dispenser returns highly formatted strings containing: Accumulated cost.