ZkTeco MiniAC Plus & ERPNext not working

Hi,
I am using ERPNext: v15.x.x-develop (73e82b7) with

  1. Essl - Aiface - Mercury
  2. ZkTeco - VF780
  3. ZkTeco - MiniAC Plus

Device 1 & 2 is working perfectly, all data is pushed to the Employee Checkin but the device 3 is not pushing data. Onace it pushed the single data to ERPNext after that it is not working, please give suggetion if anyone done this before with the ZkTeco - MiniAC Plus or you have any suggetion.

Thankyou…