A PoE (Power over Ethernet) adapter passive (D-type) typically refers to a type of adapter used in networking that provides both power and data transmission over an Ethernet cable. Here’s a breakdown of the components you mentioned:

• PoE (Power over Ethernet): This technology allows Ethernet cables to carry both data and electrical power to devices like IP cameras, VoIP phones, wireless access points, and other networked devices. PoE eliminates the need for separate power cables for these devices.

• Passive PoE: In contrast to active PoE (such as IEEE 802.3af/at standards), passive PoE does not adhere to these formal standards and works by supplying a constant voltage (often 24V or 12V) over the Ethernet cable. The devices receiving this power must be compatible with the specified voltage.

• D-Type: This term typically refers to the D-sub connector used in various types of adapters. D-type connectors are often used for serial communication and other specialized equipment.

If you're referring to a specific adapter (e.g., one that converts a PoE-enabled device to a D-type connector), it would be a passive adapter that allows you to run Ethernet power to the connected device while utilizing a D-type connector.

Do you have a particular product or use case in mind? Let me know if you'd like more detailed information!