[OS Version 1.30 2015/08/25]
1. new Feature:
  Add PPTP VPN Client function.

2. Improvement: 
  Add network type option: "Automatic", "3G only", "2G only"

------------------------------------
[OS Version 1.21 2015/04/15]
1. Fix problem: 
  RS-485 setting of "RTU Client" function always keeps in N81

2. Fix problem: 
  Log file of "RTU Client" function disappear after reboot

3. Improvement: 
  Minimum time interval of FTP report change to 3 minutes (from 1 hour)

4. Improvement:
  "Reboot Timer" can reboot at the same time

5. new Feature:
  Add FTP NAT Filter. the FTP active mode will work with 3G.

------------------------------------
[OS Version 1.20 2014/09/30]
1. Add new feature "RTU Client"

2. new function:
  Power on when rotary switch is 9 to boot with default IP "192.168.255.1"

3. new function:
  restore to factory default by hardware operation. (default IP is "192.168.255.1")
  (1)set rotary switch as 8
  (2)wire RxD3 to TxD3
  (3)power on the device

4. new function : NTP client function


------------------------------------
[OS Version 1.10 2014/01/29]
1. Add new feature "Modbus/TCP to MOdbus/RTU" for VxServer firmware.
  the user can send Modbus/TCP command in server side.
  when GRP-520 receive Modbus/TCP command, it will convert to Modbus/RTU command.

2. solve the problem:
  the ISP Chunghwa Telecom upgrades their system cause GRP-520 difficult to dial-up in Taiwan.
  the user can enable this function to avoid this problem. When GRP-520 dial-up fails, it will   try to solve this problem automatically.

3. Add new function "Reboot Timer".
  the some customer say that they need a Timer to reboot the GRP-520 automatically,
  because their system is in the place that they are hard to go again.