The IEC 61850 standard provides methods of developing best engineering practices for substation protection, integration, control, monitoring, metering, and testing. Comisi6n Federal de Electricidad (CFE) chose to build their newest integrated transmission protection and control network with IEC 61850 and evaluated the technology for possible future inclusion into their design standards.The primary IEDs chosen for protection were selected from the devices that have been approved by the customer and that also support IEC 61850. For the La Venta II project, the primary focus was to include IEC 61850 devices from as many vendors as possible rather than using traditional design criteria. In addition to the primary protection and control equipment, the customer invited all vendors to submit IEDs to be connected to the network to demonstrate their ability to communicate IEC 61850. Additional IEDs were added in an auxiliary bay because the design constraints required that the core of the network be useful and effective; it is not a demonstration control system but a pilot project to gain experience with the new standard.This system integrated 24 devices from 9 different product platforms provided by 6 different vendors. The implementation was completed in four months and included newly released products from some vendors, involved staging device communications over the Internet, and relied on contributions from engineers in seven time zones.