> For the complete documentation index, see [llms.txt](https://docs.smart-stuff.nl/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.smart-stuff.nl/p1-modbus-dongle/hardware-variants/hardware-variants.md).

# Hardware variants

Choose the hardware page that matches the product name and hardware ID shown in the Device Manager.

| Product                                                                                 | Hardware ID                                         | Use this variant for                                                                                                                        |
| --------------------------------------------------------------------------------------- | --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| [D1MC](/p1-modbus-dongle/hardware-variants/hardware-variants/d1mc.md)                   | D1MC                                                | DIN-rail installations using DSMR/P1 or HAN-NVE, with screw-terminal Modbus RTU and flexible 5 V power                                      |
| [P1 Modbus Pro](/p1-modbus-dongle/hardware-variants/hardware-variants/p1-modbus-pro.md) | NRGD, including the ZAP2/NRGDH-based implementation | Compact DSMR/P1-to-Modbus RTU installations with P1 output; the ZAP2/NRGDH-based implementation also supports HAN-NVE with an adapter cable |

{% hint style="info" %}
NRGD exists as a regular implementation and as an implementation based on ZAP2/NRGDH. The enclosure does not reliably distinguish them. Check the connection sticker because the `A` and `B` terminal positions differ; the ZAP2/NRGDH-based implementation also replaces the separate blue status LED with an RGB LED in the P1 input.
{% endhint %}

Firmware configuration and register mappings are documented once under [Firmware v2 — current](/p1-modbus-dongle/firmware-v2-current/firmware-v2.md).