Optocoupler relays can be classified according to their different characteristics and applications. Here are some common classifications of optocoupler relays:

Classified by output type:

Switch type optocoupler relay (SPST-NO): With only one switch channel, it can achieve switch operation.

Double pole double throw optocoupler relay (DPDT): It has two switch channels that can switch the connection between two different circuits.

Multi channel optocoupler relay: With multiple switch channels, it can achieve multi-channel signal transmission or isolation.

Classified by type of photosensitive element:

Photodiode: an optocoupler relay that uses a photodiode as a photosensitive component, suitable for high-speed applications.

Phototransistor: an optocoupler relay that uses a phototransistor as a photosensitive element, typically with high gain and sensitivity.

Photovoltaic FET: an optocoupler relay that uses a photosensitive field-effect transistor as a photosensitive element, suitable for low-power applications.

Classified by application field:

Industrial automation: used to control and isolate signals in industrial automation systems.

Power control: used in power switches and protective devices to achieve isolation and control.

Communication equipment: used to isolate and transmit signals between communication devices to reduce electromagnetic interference.

Medical equipment: used for signal isolation and control in medical devices.

Classified by voltage resistance:

Low voltage optocoupler relay: suitable for low voltage applications.

High voltage optocoupler relay: suitable for high voltage applications, such as those in power systems.

Please note that these classifications are only possible ways to classify optocoupler relays. Different manufacturers and application fields may classify optocoupler relays in more detail as needed.