Prepare and backup project 
  7.3 System settings 
TP 270, OP 270, MP 270B (WinCC flexible) 
Operating Instructions, Edition 03/2004, 6AV6691-1DD01-0AB0 
7-13 
7.3.2  Set operating mode 
Conditions for changing operating modes 
In order to switch the HMI device between the operating modes described below, the 
relevant function must be linked to an operating element in the configuration. 
Operating modes 
The HMI device is designed for the following operating modes: 
•  Offline mode 
•  Online mode 
•  Transfer mode 
The operating modes "Offline" and "Online" can be adjusted in the system and can be 
executed by means of a configured object. The function of transfer mode can only be 
configured as an operating element. 
Offline mode 
In this mode, there is no communication connection between the HMI device and PLC. The 
HMI device can be operated but data cannot be downloaded or received by the PLC. 
Online mode 
In this mode, a communication connection between the HMI device and PLC exists. When 
using this mode, processes in progress can be operated and visualized without restriction.  
Transfer mode 
This operating mode is used to transfer a project from the configuration computer to the HMI 
device.