Gilbarco Dispenser Twowire Protocol For Third Party Pump Controllers New __top__ May 2026
Gilbarco Two-Wire (Current Loop)
Connecting third-party pump controllers to Gilbarco dispensers requires an interface capable of managing the proprietary protocol. This protocol is a multi-drop, serial standard designed to support up to 16 fueling positions on a single communication loop . Core Protocol Specifications Signaling: Uses a 45mA current loop .
B. The Rise of Universal Protocol Converters
No communication
| Issue | Resolution | | :--- | :--- | | | Check current loop polarity – swap A/B wires. | | Intermittent drops | Ensure total loop resistance < 500Ω. Add terminator (120Ω) only at last dispenser. | | Parity errors | Third-party controller must use Even parity – not none, odd, or mark/space. | | Handle drops | Dispenser requires polling every 100-200ms; long gaps cause auto-cancel. | Add terminator (120Ω) only at last dispenser
The controller software must be designed as a Finite State Machine (FSM). The pump transitions through specific states that the controller must track: long gaps cause auto-cancel.