---
url: >-
  https://acquirer-api-docs-v4-en.pingpongx.com/en/notes/api/services/InPersonPayments/gmc/heartbeat/index.md
description: >-
  The GMC serial heartbeat interface is used to maintain the connection status
  between SAAS and POS devices. It is recommended to send a heartbeat packet
  every 30 seconds, and continuous 3 times of no response can determine that the
  device is offline. The bizContent field can be empty.
---
# GMC Serial Heartbeat Interface

```apidef
endpoint: POST /onsiteAcquirer/gmc/heartbeat
name: GMC Serial Heartbeat Interface
```

The GMC serial heartbeat interface is used to maintain the connection status between SAAS and POS devices. It is recommended to send a heartbeat packet every 30 seconds, and continuous 3 times of no response can determine that the device is offline. The bizContent field can be empty.

### Request Example

```json
{
  "accId": "PPX_ACC_202312001",
  "clientId": "PPX_MCH_20230001",
  "signType": "SHA256",
  "sign": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
  "version": "1.0",
  "event": "HEARTBEAT",
  "requestTime": "1683533500000"
}
```