Operating a project   
6.2 Function keys 
  Comfort Panels 
174  Operating Instructions, 08/2018, A5E36770603-AC 
 
Function keys 
Function keys 
Function key assignment is defined during configuration. The configuration engineer can 
assign function keys globally and locally.  
Function keys are available only on key HMI devices.  
Function keys with global function assignment 
A globally assigned function key always triggers the same action on the HMI device or in the 
controller regardless of the screen displayed. Such an action could be, for example, the 
activation of a screen or the closure of an alarm window. 
Function keys with local function assignment  
A function key with local function assignment is screen-specific and is therefore only 
effective within the active screen. 
The function assigned locally to a function key can vary from screen to screen. 
The function key of a screen can be assigned one function only, either a global or local one. 
The local assignment function takes priority over the global setting. 
The configuration engineer can assign function keys in such a way that you can manipulate 
operating elements with function keys, for example, the alarm view, trend view, recipe view 
or status/force.  
 
Direct keys on the HMI device are used to set bits in the I/O area of a SIMATIC S7.  
Direct keys enable operations with short reaction times that are, for example, a jog mode 
requirement.  
 
Note 
Direct keys are still active when the HMI device is in "offline" mode. 
 
 
Note 
If you operate a function key with direct key functionality in a running project, the direct key 
function is 
always executed, independent of the current screen contents.