光源总小时数
该 parameter 用于读取 fixture 的 total source hours。Source hours 通常表示 light source hours；对于其他 fixture types，也可以表示任意 active action 的累计时间。
应作为 supported parameter 暴露。
| Data Type | DS_UNSIGNED_DWORD | PDL Size | 4 |
| Cmd Class | CC_GET | Unit | UNITS_NONE |
| Prefix | PREFIX_NONE | Default | 0x00 |
| Min | 0x00 | Max | 0x00 |
| Description | "TOTAL_SOURCE_HOURS" | ||
GET Command 0x8404
Controller Incoming Command:
| (Port ID) | (Msg. Count) | (Sub-Device) | |
| 0x01-0xFF | 0x00 | 0x0000 (Root) or 0x0001-0x0200 | |
| (CC) | (PID) | (PDL) | |
| GET_COMMAND | TOTAL_SOURCE_HOURS (0x8404) | 0x00 | |
Controller Response:
| (Response Type) | (Msg. Count) | (Sub-Device) | |
| ACK | 0x00-0xFF | Copy of Controller SD | |
| (CC) | (PID) | (PDL) | |
| GET_COMMAND_RESPONSE | TOTAL_SOURCE_HOURS (0x8404) | 4 | |
| (PD) | |||
| Total Source Hours (32-bit) | |||
