# ECR Integration Limitations

## Overview

This page lists the known limitations and constraints when integrating an Electronic Cash Register (ECR) with Maya Terminals. Understanding these boundaries will help you design a more reliable integration and avoid unexpected issues in Production.

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## Supported Maya Terminals

ECR integration is supported in two terminal types: **Sunmi P2** and **PAX A920**.

* The **core specifications** (messaging format, request/response handling) are identical across both terminals.
* You can swap between Sunmi P2 and PAX A920 without changing your integration logic.

### Terminal-specific Limitations

| Features/Capabilities            | PAX A920                                                                | Sunmi P2                           |
| :------------------------------- | :---------------------------------------------------------------------- | :--------------------------------- |
| **Wireless ECR**                 | Supports “wireless” operation when paired with the **L920 cradle dock** | Not supported                      |
| **Custom Ads and Image Display** | Supports displaying custom ads or images on the terminal                | Not supported                      |
| **USB Drivers**                  | Requires a specific **USB driver**                                      | Requires a specific **USB driver** |

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## OS Compatibility

For ECR Integration, Maya supports the following operating systems:

* Windows
* Linux
* macOS

> Always install the correct USB driver for your terminal type and operating system. Incorrect drivers may cause communication failures.

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## FAQs

#### Q: Can I use the same codebase for both Sunmi and PAX?

**A:** Yes. The core specifications are identical. Only terminal-specific features (wireless mode, ads) differ.

#### Q: Do I need separate drivers for each OS?

**A:** Yes. Always match the driver to both the terminal and the operating system.

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## Next Steps

Now that you’re familiar with the **supported terminals** and **OS compatibility**, proceed to the next stage of your ECR integration:

* Learn how **asynchronous** and **synchronous** flows work to ensure your ECR integration communicates effectively with the Maya Terminal, see: [Asynchronous and Synchronous Flows in ECR Integration](/reference/asynchronous-and-synchronous-flows-in-ecr-integration)