# Check

## Function

This API is used for the standby manager to make cyclic requests to the working device and the common standby to obtain appeal information.

## Request Message

### Parameter Description

#### Table 1

Parameter | Range | Type | Description
--- | --- | --- | ---
request_type | "active", "passivity" | string | The type of request, whether it is actively obtained or passively received.

Sample:

    POST /API/RecordPatch/Check HTTP/1.1

    {
    	"request_type": "active"
    }

## Response Message

### Parameter Description

#### Table 2

Parameter | Range | Type | Description
--- | --- | --- | ---
channels | "All" "CH1"…"CHx" "IP_CH1"…"IP_CHx" "WIFI_CH1"…"WIFI_CHx" | string array | The channel where changes occur. Dedicated for the working device.
record_patch |  | object array | Dedicated for the hot standby device.For detailed information, please refer to Table 3

#### Table 3

Parameter | Range | Type | Description
--- | --- | --- | ---
ip |  | string | The IP address of the working device.
status | "start", "working", "end", "idle" | string | The status of the working device's request for video recordings from the hot standby device.

Sample:

1. Worker:

    HTTP/1.1 200 OK
    Content-Type: application/json

    {
        "data": {
            "channels":["ALL"]
        }
    }

2. Standy:

    HTTP/1.1 200 OK
    Content-Type: application/json

    {
        "data": {
            "record_patch": [
                {
                    "ip": "172.18.1.210",
                    "status": "start"
                }
            ]
        }
    }