0x40A3 · fnInversionMultiHost

fnInversionForMultiHostDevices 控制 F 行按键默认以标准功能键还是以标注的媒体键 / 特殊功能行为。与单主机前代版本 0x40A2（fnInversionWithDefaultState）不同，此变体为每个主机槽位独立存储翻转状态。

getGlobalFnInversion（function 0）读取指定 HostIndex 的当前状态、出厂默认状态及设备能力。setGlobalFnInversion（function 1）为主机槽位写入所需的 FnInversionState；设备将该值持久化在自身的非易失性存储中，并返回生成的 FnInversionInfo。

• FnInversionState —— Off（F 键按标注功能键行为），On（F 键按媒体键 / 特殊功能行为）。
• FnInversionCapabilities —— MANUAL_FN_LOCK 标志位表示设备支持手动 Fn 锁控制。
• FnInversionInfo —— 响应结构体，包含 host_index、state、default_state 与 capabilities。

规格： Logitech HID++ 2.0 —— fnInversionForMultiHostDevices。用于： openlogi-hidpp 中的类型化封装。

Function reference

The FnInversionMultiHostFeature wrapper (0x40a3) exposes:

Methods

All methods are async and return Result<_, Hidpp20Error>.

Types

FnInversionInfo

Function-key inversion state for a host slot.

FnInversionState

Function-key inversion state.

FnInversionCapabilities

Function-key inversion capabilities (bitflags).

HostIndex

A host slot selector (defined in hosts_info).

Wire format

Requests carry a 3-byte payload; responses are parsed from the 16-byte long payload returned by extend_payload().

get_global_fn_inversion (fn 0)

Request: [host_index, 0x00, 0x00]

• Byte 0: host_index — u8 encoding of HostIndex (0xff = current slot, 0x00–0xfe = zero-based slot index)
• Bytes 1–2: reserved, always 0x00

Response (byte → field):

set_global_fn_inversion (fn 1)

Request: [host_index, state, 0x00]

• Byte 0: host_index — u8 encoding of HostIndex
• Byte 1: state — u8 encoding of FnInversionState (0 = Off, 1 = On)
• Byte 2: reserved, always 0x00

Response (byte → field): identical layout to get_global_fn_inversion — the device echoes back the resulting FnInversionInfo for the host slot.

Usage (Rust)

use hidpp::{
    device::Device,
    feature::fn_inversion::{FnInversionMultiHostFeature, FnInversionState},
};

// mut device: Device, already created via Device::new(channel, index)
device.enumerate_features().await?;
if let Some(feat) = device.get_feature::<FnInversionMultiHostFeature>() {
    // Read the current state for the active host slot.
    let info = feat.get_global_fn_inversion(hidpp::feature::hosts_info::HostIndex::Current).await?;
    println!("state={:?}, default={:?}, caps={:?}", info.state, info.default_state, info.capabilities);

    // Enable Fn-inversion on host slot 0.
    let updated = feat
        .set_global_fn_inversion(hidpp::feature::hosts_info::HostIndex::Slot(0), FnInversionState::On)
        .await?;
    println!("new state={:?}", updated.state);
}