Introduction
This guide explains how to design the TAP layout and CCA assignment for a Tigo TS4 system, covering both residential and commercial installations. It walks through the system architecture, the mesh communication technology, the factors that can affect signal quality, and the rules for determining the correct number and position of TAPs and CCAs for different installation types.
While this guide gives you everything you need to design a system independently, we strongly recommend involving the Tigo Sales Engineering team through the Green Glove Service — especially for commercial projects or any installation with complex geometry. The service is free of charge and includes a professional pre-installation design review, on-call support during installation, and a post-installation check to confirm the system is operating at 100%.
A correctly designed TAP layout is not just about monitoring performance — it is a safety requirement for Rapid Shutdown compliance. Getting it right from the start ensures every module is covered, and gives you full confidence in power production and safety capabilities of the system before it goes live.
To request a Green Glove Service design review: tigoenergy.com/green-glove-service
(Include the array layout with the string configuration, inverter & PV module datasheet and any other related documentation)
Contents:
- System Architecture: TAP and CCA
- The Tigo Mesh Network
- What Can Block the TAP Signal
- TAP Count: Residential
- TAP Count: Commercial
- CCA Count and Assignment
CHAPTER 1
System Architecture: TAP and CCA
A Tigo TS4 system is built around three components that work together: the TS4 MLPE unit on each module, the TAP (Tigo Access Point) in the field, and the CCA (Cloud Connect Advanced) data logger.
The TS4 Unit
The TS4 is attached to each PV module and handles optimization, monitoring, or both depending on the model. It communicates wirelessly with the TAP, sending production data and listening for Rapid Shutdown commands.
The TAP — Tigo Access Point
Mounted within the array, the TAP is a communication unit that acts as the primary wireless access point for the local site. It collects data from the TS4 units and relays it to the CCA via a communication cable, while also transmitting Rapid Shutdown signals back to the modules.
The CCA — Cloud Connect Advanced
The CCA is the system controller and data logger. It collects data from all connected TAPs, sends performance information to the Tigo Cloud platform, and triggers the Rapid Shutdown response when required. When a shutdown signal is received, the CCA instructs all TAPs to stop transmitting — causing every TS4 in the array to de-energize within the required time.
CHAPTER 2
The Tigo Mesh Network
Communication between the TAP and the TS4 units does not rely on a simple point-to-point wireless link. Tigo uses a proprietary mesh network in which each TS4 unit acts as both a receiver and a repeater, relaying the signal outward to neighboring modules. This allows a single TAP to cover an array much larger than its direct wireless radius.
The TAP seeds the mesh by communicating directly with the TS4 units closest to it. Those units relay the signal to the next row, and so on, forming a chain across the full array.
The mesh only works when TS4 units form an unbroken chain from the TAP outward. A gap in the array larger than approximately 10 meters — caused by a missing row, an HVAC unit, or a section of roof with no modules — breaks the mesh path. Modules on the far side of the gap lose communication and Rapid Shutdown coverage. Place an additional TAP beyond any such gap to re-seed the mesh.
Rapid Shutdown and the mesh
The Rapid Shutdown command travels through the same mesh. When Rapid Shutdown is activated, the TAP stops transmitting the "keep alive" signal. Every TS4 unit that can no longer hear the signal will automatically de-energize. The system is doing exactly what it was designed to do.
Where mesh continuity makes the real difference is in production and monitoring. A complete, unbroken mesh means every module stays connected, every watt-hour is tracked, and module-level optimization can work across the full array. A well-designed mesh is what allows the system to deliver its full potential, day after day.
The TAP seeds the mesh by reaching the nearest TS4 units directly (red). Each unit relays the signal outward — orange for the second hop, yellow for the third — extending TAP’s coverage.
CHAPTER 3
What Can Block the TAP Signal
Mesh communication is very powerful in its ability to overcome obstacles by having the signal hop between one TS4 and another. However, the TAP signal can be weakened or blocked by some physical objects, elevation changes, and roof materials.
Physical obstacles
The most common signal obstructions on rooftops are:
- Roof ridges and hips — each side of a ridge must be treated as a separate coverage zone with its own TAP.
- Parapet walls — solid masonry or concrete structures fully block the signal. Modules separated by a parapet cannot share a TAP.
- HVAC equipment — large metal units reflect and absorb the radio signal. Any module rows behind HVAC equipment from the TAP's perspective will experience reduced signal quality.
- Chimneys, skylights, and dormers — any raised roof feature sitting between the TAP and a row of modules creates a shadow zone.
- Module gaps > 10 m — break the mesh chain and prevent signal propagation to modules on the far side.
Height changes
A drop in roof level of more than 1 meter (3 feet) between two array sections is treated as a full signal obstruction, even with no physical wall between them. The change in elevation breaks line-of-sight sufficiently that the upper TAP cannot seed the mesh on the lower section. An additional TAP is required on the lower field whenever this occurs.
Roof material
Roofing materials (like metal or tile) can affect the system's ability to maintain a quality signal. This is due to their reflective and impenetrable nature. In chapter 5 of this guide different conditions will be covered.
CHAPTER 4
TAP Count: Residential
For residential installations, TAP(s) is always installed on the roof. Three rules determine how many TAPs are needed.
Rule 1 — One TAP per orientation (default)
Each distinct roof face with modules pointing in a different direction needs its own TAP. A roof ridge between two orientations blocks line-of-sight; each side must be covered independently.
Rule 2 — Convex transition exception
If two adjacent roof sections meet at a convex angle (the roof steps outward), line-of-sight is preserved across the transition. One TAP placed near the junction can cover both sections. This does not apply to concave (valley) transitions.
Rule 3 — Height change requires an extra TAP
Any section of the array that drops more than 1 m (3 ft) from the main roof level needs its own TAP. Common examples include step-down garage roofs and lower porch extensions.
Placement tips
- Centre the TAP within its assigned array to maximize uniform radius in all directions.
- Maintain at least 10 meters between any two TAPs to avoid radio interference.
- Avoid placing the TAP near a ridge, chimney, dormer, or the edge of the array.
CHAPTER 5
TAP Count: Commercial
Commercial systems vary widely in scale and roof geometry. The scenarios below cover the most common architectures. In all cases, maintain a minimum separation of 10 metres between any two TAPs to prevent radio interference.
Flat roof with concrete or membrane surface
This is the most common commercial scenario. Modules are mounted on ballasted or tilted-rack systems with standard clearance from the roof surface. The most optimal TAP radius is 18 meters.
Place one TAP at the center of each contiguous array section. If the section is wider than 18 m in any direction from the center point, split it into two zones and place one TAP per zone. Add a TAP on the far side of any parapet wall, HVAC unit, or module gap larger than 10 m — these all break the mesh and require independent coverage.
Metal or tile roof
Metal and tile surfaces reflect and attenuate the TAP signal, reducing the optimal radius to 13 meters. The placement logic is the same as for a flat roof, but expect more TAPs per square meter of array compared to a concrete roof installation.
For multi-orientation layouts on metal roofs, apply the 13 m radius independently to each roof face. Do not attempt to cover two faces from a single TAP across a ridge.
Ground mount, carport, or elevated structure
Elevated structures offer the best signal conditions. With no reflective roof surface directly beneath the array, the effective TAP radius reaches up to 35 meters. A single TAP can cover a large ground-mounted array, provided the module rows form an unbroken mesh chain with no gaps larger than 10 m between strings.
For very long ground-mount arrays — tracker rows, for example — check whether the far end of the array falls within 35 m of the TAP. If not, add a second TAP at the far end.
Multi-building or multi-roof installations
When the array spans several rooftops or building sections separated by open gaps, each section must be treated as an independent coverage zone. The radio signal cannot bridge the gap between buildings. Place at least one TAP per building section and connect all TAPs back to the CCA via RS-485 cable.
CHAPTER 6
CCA Count and Assignment
The CCA controls Rapid Shutdown for every TS4 unit assigned to it. Correct CCA assignment is a safety requirement, not just a configuration preference.
How many TAPs per CCA?
A single CCA can manage up to 7 TAPs. Systems with more than 7 TAPs need at least two CCAs. Divide TAPs across CCAs respecting the MPPT assignment rule below.
How many TS4s per TAP or CCA?
A single TAP can manage up to 300 TS4 units, provided the physical placement requirements described in this guide are met. A single CCA can manage up to 900 TS4 units across all its connected TAPs.
How many TAPs are there in Residential systems?
Most residential systems have one to three TAPs and a single inverter. Assign all TAPs to one CCA.
How many TAPs and CCAs are there in Commercial systems?
The fundamental rule: every MPPT and all strings connected to it must belong to a single CCA. An MPPT must never be split across two CCAs.
Splitting an MPPT means neither CCA has full control of it. When Rapid Shutdown is triggered, one CCA de-energizes its share while the other may not respond in time, leaving some modules energized — a safety non-compliance condition.
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Recommended: one CCA per inverter
Each inverter gets its own CCA. All MPPTs and strings are unambiguously under one controller. Rapid Shutdown is clean and complete. -
Allowed: one CCA for multiple inverters
Permitted if no single MPPT is split across two CCAs. Typically, viable for smaller commercial systems with a low TAP count. -
Not allowed: any MPPT split across two CCAs
Explicitly prohibited. Verify CCA assignment at the string level before commissioning.