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

The RS-232 to Two-Wire Converter Box is an essential diagnostic tool and alternative interfacing component. Its primary functions are to:

Controller approved the sale, dispenser preparing to pump.

The most critical thing to understand about the Gilbarco Two-Wire protocol is that it is not RS-232 or RS-485 at the physical layer. It is a . The RS-232 to Two-Wire Converter Box is an

: Units like Highline-111 and the Advantage series often use a "Corporate" baud rate of 5787 bps .

. While the protocol itself dates back to the late 1980s, its continued use in modern units like the Gilbarco Encore 500 It is a

: 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

The Gilbarco Two-Wire protocol is a proprietary, standard used to link fuel dispensers with point-of-sale (POS) systems or third-party pump controllers . It operates as a master-slave system where the controller (master) initiates all communication, and individual dispensers (slaves) respond only when addressed. 1. Technical Specifications While the protocol itself dates back to the

When a third-party controller detects an "Authorize Request", it evaluates the authorization source (e.g., an indoor POS, an outdoor payment terminal, or a mobile app fleet authorization). If approved, the controller sends an Authorization frame containing:

Gilbarco proprietary systems send a "Resettle" command every 60 seconds to clear hanging transactions. Third-party controllers often forget this.

Messages consist of a preamble, device address, command byte, data payload, and a Longitudinal Redundancy Check (LRC) byte for error detection. 1. Status Request (Polling)