Overview 
  1.8 Terms for fail-safe operation 
Mobile Panels 2nd Generation 
Operating Instructions, 09/2018, A5E33876626-AC 
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Safety-related operating mode 
In fail-safe mode, you can use the HMI device in combination with a connection box in one of 
the following operating modes: 
●  Stop button evaluated by safety relay 
This operating mode is intended for a hardwired F-system. The signals of the safety-
related operator controls are wired to a safety relay. If you press the  
emergency stop / stop button, the plant typically responds with a stop. 
The emergency stop / stop button does not light up. 
In this operating mode, the emergency stop / stop button is called the 
. 
●  E-stop button evaluated by safety relay 
This operating mode is intended for a hardwired F-system. The signals of the safety-
related operator controls are wired to a safety relay. When you press the emergency stop 
/ stop button, the plant responds with an emergency stop. 
The emergency stop / stop button lights up when active. 
In this operating mode, the emergency stop / stop button is called the 
. 
●  E-stop button evaluated by PROFIsafe 
This operating mode is intended for a PROFIsafe-based F-system. If you press the 
emergency stop / stop button, an emergency stop is triggered in the plant. 
The emergency stop / stop button lights up when active, that is, if the HMI device has 
been registered in the safety program. 
In this operating mode, the emergency stop / stop button is called the 
. 
Emergency stop / stop bypass 
The emergency stop / stop bypass is a function of the connection box advanced for 
hardwired F-systems. 
The function ensures that no stop or emergency stop will be triggered in the plant when 
reconnecting the Mobile Panel to another connection box. 
PROFIsafe communication, logon and logoff in the safety program  
The following applies in a PROFIsafe-based F-system for the logon and logoff of the fail-safe 
Mobile Panel to a safety program: 
If you have connected the fail-safe HMI device with a connection box and started the HMI 
project, the HMI device is automatically logged onto the safety program. After logon, the fail-
safe HMI device is integrated into PROFIsafe communication and the emergency stop button 
and enabling button become active.