Introduction
Traffic signal projects may specify NEMA TS-2, an ATC controller and cabinet architecture, or agency-specific equipment such as Caltrans installations. These specifications address different layers and must not be treated as identical packages. Establish the authority’s approved standard editions, interfaces and environmental requirements before selecting equipment.
NEMA TS-2: The North American Workhorse
NEMA TS-2 distinguishes Type 1 and Type 2 controller assemblies. Type 1 uses an SDLC link to communicate with cabinet equipment; Type 2 also provides legacy parallel interfaces. Confirm the specified type, standard edition, cabinet wiring and controller documentation. Do not describe all TS-2 interfaces as one 37-pin connector or assume central-system integration is identical for every product.
Standardized interfaces can support interchangeability, but replacement is conditional. Verify the exact controller and cabinet types, standard editions, connectors, I/O mapping, electrical ratings, monitoring, firmware and communications. Obtain documented compatibility and complete acceptance testing before treating a different manufacturer’s unit as a drop-in replacement.
ATC 5.2b: The Modern Successor
The ATC family provides an open hardware and software platform for transportation applications. Controller architecture, cabinet architecture and application interfaces are covered by separate standards: ATC 5201, ATC 5301 and ATC 5401. Specify the required editions, cabinet interfaces, application software and communications, then verify the selected product’s implementation. ATC architecture alone does not establish NTCIP support or automatic application portability across links.
Select controller and cabinet standards from the authority’s requirements and the existing installation. For new work, specify the approved editions and required functions rather than assuming one architecture is universally preferred. For replacements, verify electrical, mechanical, software and communications compatibility. Confirm GAOQIAO’s offered configuration and supporting documents in the project quotation.
Caltrans 170/2070: The California Standard
Caltrans TEES 2009 specifies a different cabinet form factor (the 170-style cabinet) and the 2070 controller unit. The Caltrans 170/2070 ecosystem is required on California state highway projects and adopted by several neighbouring states. If your project is in California or a state that follows Caltrans, you need a 2070-compatible controller; a TS-2 or ATC controller will not drop into a 170 cabinet without a substantial adapter.
For a Caltrans 170/2070 project, confirm the authority’s current approved equipment list, procurement requirements and required interfaces. Ask GAOQIAO to confirm product availability and compatibility in writing for the specific configuration.
Choosing the Right Standard
| Document family | Scope to verify | Interface checks |
|---|---|---|
| NEMA TS-2 | Traffic controller assemblies; confirm the required edition and assembly type | Type 1 uses SDLC interfaces; Type 2 also supports parallel interfaces. Verify actual connectors and approved wiring |
| ATC standards | Controller, cabinet and application interface requirements are covered by separate ATC documents | Confirm the selected controller I/O, cabinet interface and software support; ATC alone does not establish interchangeability |
| Caltrans 170/2070 | Confirm the authority-required specification edition, controller configuration and cabinet assembly | Verify the approved equipment drawings, power, connector assignments, software and acceptance requirements |
Featured Products
GAOQIAO supplies TS-2 and ATC compatible controllers for North American projects. See the controller cabinet guide and the compatibility checklist for procurement details.
Conclusion
Select controller and cabinet standards from the authority’s requirements and the existing installation. For new work, specify the approved editions and required functions rather than assuming one architecture is universally preferred. For replacements, verify electrical, mechanical, software and communications compatibility. Confirm GAOQIAO’s offered configuration and supporting documents in the project quotation.
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Frequently Asked Questions
Can a TS-2 controller run in an ATC cabinet?
Compatibility depends on the selected controller’s field I/O interface, cabinet architecture, software and approved wiring. An ATC controller is not automatically restricted to an ATC cabinet, nor is it automatically compatible with every TS-2 cabinet. Obtain a documented compatibility assessment for the exact combination before procurement.
Which standard is required for projects in Texas, Florida or New York?
Most states outside California accept either NEMA TS-2 or ATC. Confirm with the authority before procurement; many specify ATC for new projects and TS-2 for retrofits into legacy cabinets.
Does GAOQIAO supply Caltrans 170 controllers?
For a Caltrans 170/2070 project, confirm the authority’s current approved equipment list, procurement requirements and required interfaces. Ask GAOQIAO to confirm product availability and compatibility in writing for the specific configuration.
How long does it take to migrate from TS-2 to ATC?
The cabinet wiring is unchanged, so a TS-2 to ATC swap is typically a one-day controller replacement. The bigger work is the firmware update and the new operator training.
Relevant GAOQIAO products
These public GAOQIAO catalogue pages are related to the guide. Open them for the representative description, then confirm the latest drawing and configuration before ordering.
- Traffic signal controllersWired and solar controllers with 6, 22, 44 and 56 output options.
- LED traffic signal heads200mm, 300mm and 400mm signal heads with MUTCD, EN12368, GB14886 compliance.
- Signal polesVertical, signal arm and double-arm poles for any intersection geometry.
- Spare parts and accessoriesSpare LED modules, lenses, visors, surge arrestors and anchor bolts.