Legacy Wireless Communication - STAR wireless communications mode.
The following describes our legacy communication architecture. Most of our Gateway product are capable of also using the new Mesh wireless communication architecture when all other requirements are met. See "TAP and Mesh" for details.
System Overview
A Tigo-optimized PV system consists of four key components:
- Cloud Connect or Cloud Connect Advanced (CCA)
- TAP or Gateway
- Tigo MLPEs (module level power electronics)
- Inverter
The number of TAPs/Gateways and Cloud Connects/CCAs needed for a system are determined by both the number of modules and the size and layout of the installation.
See also our other articles: TAP vs Gateway and TAP Placement.
Gateway basics
- Up to seven Gateways can be connected in series to each Cloud Connect Advanced, Cloud Connect, or MMU using RS-485 cable (not included.)
- Each Gateway can communicate with up to 120 Tigo-equipped modules.
- The communication distance of a Gateway has a maximum radius of 50ft (15m) to optimizers.
- If modules are located more than 50ft (15m) from the Gateway, use additional Gateways.
Multiple Gateways Needed?
For systems with more than 120 modules, or where modules are located more than 50ft (15m) from the Gateway, multiple Gateways will be connected in series (daisy chained) on the same RS-485 cable. Systems with multiple orientations, such as east facing and west facing, should have one Gateway on each plane of the array.
Gateways in series, i.e. Daisy-chained to 1 RS-485 cable.
Complete Coverage
Obstacles such as chimneys, dormers, and AC units can prevent line-of-sight between a Gateway and a MLPE, which can reduce the effective communication range of the Gateway. To ensure complete coverage, re-position and/or add Gateways within range and line-of-sight of all modules. A height change of more than 3 feet (1m) is considered an obstruction.
Gateways placed around an obstruction
Residential: Example Gateway Placements:
L-shaped house with one Gateway (above image).
L-shaped house with dormer which may need 2 Gateways.
L-shaped house with multiple array plane orientations. The radio signal can not propagate through roofing materials effectively.
Multiple distance seperated rooftops.
Summary: Requirements for a Successful Gateway Design
The below pieces of information are required to create a gateway design that will successfully communicate with all modules in a system:
- A map or layout of the modules in the system
- A method for creating a distance scale for the site. A line of 15 meters or 50 feet must be able to be drawn accurately to represent the gateway's communication radius. This can be done easily in 2 ways:
- Providing a map or layout of the modules which includes a distance scale
- Providing the dimensions of the modules used on site
- The position of physical obstructions within the array that block gateway line of sight to modules
- FOR MULTI-INVERTER SYSTEMS OVER 360 MODULES: The stringing assignment of each inverter.
- Strings cannot be split across Cloud Connects/CCA's
Additional Information
During the Discovery process, the Cloud Connect or MMU will assign MLPEs to the best available Gateway based on wireless signal strength. When designing a system with multiple Gateways, allow some overlap in the communication range between neighboring Gateways for best results.
Gateways should always be mounted to the frame of a module whenever possible, but a Gateway can also be mounted in an attic depending on the roofing materials used. Not recommended for metal roofing.