The Gilbarco Two-Wire protocol operates strictly on a Master-Slave topology. The third-party pump controller acts as the Master (POS/Forecourt Controller), and the fuel dispensers act as Slaves.
Unlike modern Ethernet (TCP/IP) which requires complex switching and addressing, the two-wire protocol uses a current loop. A master controller (traditionally a Gilbarco POS) sends commands by modulating current on the loop. Dispensers listen for their unique address and respond on the same two wires. The Gilbarco Two-Wire protocol operates strictly on a
| Feature | Two-Wire (New Method) | Ethernet / IFSF | Traditional DBox | | :--- | :--- | :--- | :--- | | | <20ms (Critical for presets) | 100-200ms | 500ms+ | | Cabling Cost | Low (existing twisted pair) | High (Cat6/Fiber needed) | Very High (Proprietary) | | Third-Party Support | Newly accessible via converters | Native (if dispenser supports) | Poor (license fees) | | Legacy Dispensers | Works on 20-year-old units | Requires new dispenser | Works but costly | A master controller (traditionally a Gilbarco POS) sends
Gilbarco Two Wire Pump Protocol - TOAZ - INFO | PDF - Scribd This article is for informational purposes
Disclaimer: Gilbarco Veeder-Root is a registered trademark. This article is for informational purposes. Always consult with a certified fuel systems integrator and adhere to local electrical codes (NEC Article 514) before modifying dispenser wiring.
Breakdown: Start (*), Address (04), Preset (P), 2000 (cents), Stop (L).
The PPC must be capable of: